246 results on '"Bacteriocinas"'
Search Results
2. Compuestos bioactivos en quesos: biosíntesis, actividad biológica y contribución de las bacterias ácido lácticas
- Author
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Joel López-Mendoza, Lourdes Adriano-Anaya, Didiana Gálvez-López, and Alfredo Vázquez-Ovando
- Subjects
ácido gamma-aminobutírico ,aminas biogénicas ,bacteriocinas ,cultivo iniciador ,alimentos funcionales ,Agriculture - Abstract
Introducción. A partir de 1990 se ha observado un incremento en la tasa de enfermedades asociadas con dietas poco saludables y estilos de vida sedentaria, cuya atención supone un reto para los sistemas de salud. Lo anterior, ha despertado el interés por los alimentos funcionales, es decir, aquellos que además de proporcionar macro y micronutrientes, aporten sustancias que poseen efecto fisiológico en el organismo, lo que se traduce en la mejora de la salud de quien lo ingiere. De manera genérica a estos compuestos se les conoce como bioactivos. Objetivo. Revisar las principales sustancias bioactivas reportadas en quesos, el papel de los microorganismos en la producción de las mismas y las rutas de biosíntesis de los principales compuestos. Desarrollo. La leche y sus derivados son productos alimenticios consumidos alrededor del mundo y presentan un incremento constante en su producción y consumo. Esta tendencia de mercado es debida a su sabor y aporte nutrimental. Uno de los derivados lácteos con mayor demanda en el mundo son los quesos. Son una fuente de sustancias como péptidos, ácidos grasos, vitaminas, bacteriocinas, ácidos orgánicos, ácido gamma aminobutírico, etc., todas con importante actividad biológica. Conclusión. La presencia, cantidad y disponibilidad de los compuestos bioactivos presentes en los quesos difiere, como resultado del tipo de leche empleada para su elaboración, el tipo de microorganismo empleado, ya sea como cultivo iniciador o secundario, así también como el proceso tecnológico empleado.
- Published
- 2023
- Full Text
- View/download PDF
3. Evaluation of Lactic Acid Bacteria (LAB) against Shigella sonnei ATCC 25931.
- Author
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Cortés-Gaona, María del Pilar and Amorocho-Cruz, Claudia Milena
- Subjects
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LACTIC acid bacteria , *SHIGELLA , *CEFTRIAXONE , *ORGANIC acids , *COFFEE beans , *NUTRITIONAL value , *PATHOGENIC microorganisms , *BREAST milk , *ANTI-infective agents - Abstract
The main functions of Lactic Acid Bacteria (LAB) are the production of organic acids and their characteristic as inhibitors of pathogenic microorganisms. Disease caused by Shigella sonnei is a public health risk factor, as is the resistance they develop to antibiotics. Accordingly, in this study 4 LAB isolated from coffee, quesillo, and breast milk were evaluated under in vitro conditions on Shigella sonnei, considering the presence and cell-free filtration of LAB. The LAB strains were also studied via an antibiotic test using Penicillin, Ceftriaxone, and Ciprofloxacin. The results showed antagonistic activity against Shigella sonnei due to the presence of cells and organic acids. However, the LAB bacteriocins did not inhibit the pathogen. Furthermore, LABs were sensitive to the antibiotics tested. Products from the region such as coffee and quesillo, as well as breast milk are important for their nutritional value and for their LAB content. It would be useful to involve biotechnological research in the coffee and dairy chain on the one hand, and to promote breastfeeding on the other. The tests carried out are qualitative and the inhibitory effect is attributed to the strain and not to a generalization of species. It would also be useful to perform molecular identification of the lactic acid strains studied to introduce them in other food matrices, to evaluate their viability, and to carry out in vivo tests to assess their antimicrobial activity. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
4. Las bacteriocinas y su efecto sinérgico con tecnologías emergentes en alimentos.
- Author
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Castellanos-Rozo, José, Galvis-López, Jaqueline A., Pérez Pulido, Rubén, Grande, Ma. José, Lucas, Rosario, and Gálvez, Antonio
- Subjects
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LACTIC acid bacteria , *HYDROSTATIC pressure , *TECHNOLOGICAL innovations , *FOOD preservatives , *BACTERIOCINS , *ESSENTIAL oils , *BACTERIOPHAGES , *PATHOGENIC bacteria - Abstract
Bacteriocins --peptides synthesized by bacteria that have great potential as food preservatives--are a good alternative to replace chemical additives and produce minimally processed foods. The more widely studied bacteriocins in the food industry are those derived from lactic acid bacteria (LAB) because they are Generally Regarded As Safe (GRAS). However, bacteriocins have certain disadvantages when applied to food, especially dairy products. Such drawbacks can be remedied by combining bacteriocins with other treatments emerging from the food industry. The objective of this research was to analyze the main bacteriocins used and their synergistic effect on pathogenic and/or spoilage bacteria, when applied in combination with other treatments such as chemical substances, lactoperoxidase system, high hydrostatic pressures, nanoparticles, bacteriophages and essential oils. The results of this study indicate that applying bacteriocins with other treatments can increase antimicrobial activity, which improves food safety. It is concluded that the best combinations of bacteriocins and emerging technologies are bacteriocins and nanoparticles and bacteriocins with bacteriophages, whose combinations inhibit the growth of both Gram-positive and Gramnegative bacteria. The advantages that such combinations offer are: They are easily applied to foods, are low cost, do not modify the sensory characteristics of the product, allow combating antimicrobial resistance and completely destroy microorganisms without giving them the opportunity to recover during the maturation or storage period. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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5. Las bacteriocinas y su efecto sinérgico con tecnologías emergentes en alimentos
- Author
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José Castellanos-Rozo, Jaqueline Arleth Galvis López, Rubén Pérez Pulido, María José Grande Burgos, Rosario Lucas, and Antonio Gálvez
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inocuidad ,bacteriocinas ,queso ,patógenos ,Science ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
Las bacteriocinas son péptidos sintetizados por bacterias que presentan un amplio potencial como conservador de alimentos. Son una buena alternativa para reemplazar los aditivos químicos y producir alimentos mínimamente procesados. Las bacteriocinas que se han estudiado con mayor interés en la industria alimentaria son las derivadas de bacterias ácido-lácticas (bal) porque tienen el estatus Generally Regarded As Safe (gras). No obstante, se ha determinado que las bacteriocinas tienen ciertas desventajas a la hora de aplicarlas en los alimentos, especialmente en derivados lácteos. Esas desventajas pueden enmendarse al combinar las bacteriocinas con otros tratamientos emergentes en la industria alimentaria. El objetivo de esta revisión fue realizar un análisis sobre las principales bacteriocinas utilizadas y su efecto sinérgico contra bacterias patógenas y/o alteradoras, cuando se aplican de manera combinada con otros tratamientos como sustancias químicas, sistema lactoperoxidasa, altas presiones hidrostáticas, nanopartículas, bacteriófagos y aceites esenciales. Los resultados de esta revisión indican que cuando se aplican las bacteriocinas con otros tratamientos pueden aumentar la actividad antimicrobiana, lo cual mejoraría la seguridad alimentaria. Se concluye que las mejores combinaciones del uso de las bacteriocinas y tecnologías emergentes son bacteriocinas y nanopartículas y bacteriocinas con bacteriófagos, cuyas combinaciones inhiben el crecimiento tanto de bacterias Gram positivas como de Gram negativas, entre las ventajas están, fáciles de aplicar en los alimentos, pueden ser de bajo costo, no cambian las características sensoriales del producto, permiten combatir la resistencia antimicrobiana, y destruyen completamente a los microorganismos sin darles oportunidad de recuperación durante el periodo de maduración o almacenamiento.
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- 2022
- Full Text
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6. Efecto de la nisina en la inhibición del crecimiento de Staphylococcus areus y en las propiedades sensoriales del queso costeño
- Author
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Beatriz Alvarez Badel, María Alejandra Doria Espitia, Vanesa Hodeg Peña, Mónica María Simanca Sotelo, Yenis Pastrana Puche, and Claudia Denise De Paula
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Bacteriocinas ,Concentración mínima inhibitoria ,S. aureus ,Animal culture ,SF1-1100 ,Veterinary medicine ,SF600-1100 - Abstract
Se evaluó el efecto de la adición de nisina en queso costeño obtenido en la ciudad de Montería – Córdoba, Colombia, sobre la inhibición del crecimiento de Staphylococcus aureus y sobre las características sensoriales del queso. Se obtuvieron muestras de queso costeño en 9 comercializadoras de la ciudad y se aisló S. aureus, se determinó la concentración mínima inhibitoria (CMI) con nisina; se elaboró queso costeño con la adición de nisina a 0, 500 y 625 UI/kg. Se realizó el recuento de S. aureus, a las 0 y 24 h de almacenamiento; se estableció un diseño completamente al azar con 57 unidades experimentales. Se realizó una prueba triangular con panel de 40 catadores para determinar diferencias sensoriales entre el queso costeño tradicional y con adición de nisina. Se determinó que el queso costeño presentó contaminación por S. aureus; dichas cepas fueron inhibidas con una CMI de nisina de 500 UI/ml. Los recuentos de S. aureus en queso costeño adicionado con nisina presentaron diferencias significativas (P≤0.05) con el testigo; se observó que después de 24 h la nisina redujo de 2.3 ciclos logarítmicos para concentración de 500 UI/kg y 1.9 ciclos logarítmicos para 625 UI/kg. El queso costeño adicionado con 500 UI de nisina/kg no presentó diferencias (P≥0.05) en las propiedades sensoriales con relación al testigo. Se concluye que la nisina a 500 UI/ml inhibe al S. aureus aislado del queso costeño comercializado en la ciudad de Montería- Córdoba.
- Published
- 2022
- Full Text
- View/download PDF
7. Bioactive compounds in cheeses: biosynthesis, biological activity, and contribution of lactic acid bacteria
- Author
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Joel López-Mendoza, Lourdes Adriano-Anaya, Didiana Gálvez-López, and Alfredo Vázquez-Ovando
- Subjects
aminas biogénicas ,ácido gamma-aminobutírico ,gamma-aminobutiryc acid ,cultivo iniciador ,starter culture ,Soil Science ,biogenic amines ,Agronomy and Crop Science ,alimentos funcionales ,functional foods ,bacteriocins ,Food Science ,bacteriocinas - Abstract
Resumen Introducción. A partir de 1990 se ha observado un incremento en la tasa de enfermedades asociadas con dietas poco saludables y estilos de vida sedentaria, cuya atención supone un reto para los sistemas de salud. Lo anterior, ha despertado el interés por los alimentos funcionales, es decir, aquellos que además de proporcionar macro y micronutrientes, aporten sustancias que poseen efecto fisiológico en el organismo, lo que se traduce en la mejora de la salud de quien lo ingiere. De manera genérica a estos compuestos se les conoce como bioactivos. Objetivo. Revisar las principales sustancias bioactivas reportadas en quesos, el papel de los microorganismos en la producción de las mismas y las rutas de biosíntesis de los principales compuestos. Desarrollo. La leche y sus derivados son productos alimenticios consumidos alrededor del mundo y presentan un incremento constante en su producción y consumo. Esta tendencia de mercado es debida a su sabor y aporte nutrimental. Uno de los derivados lácteos con mayor demanda en el mundo son los quesos. Son una fuente de sustancias como péptidos, ácidos grasos, vitaminas, bacteriocinas, ácidos orgánicos, ácido gamma aminobutírico, etc., todas con importante actividad biológica. Conclusión. La presencia, cantidad y disponibilidad de los compuestos bioactivos presentes en los quesos difiere, como resultado del tipo de leche empleada para su elaboración, el tipo de microorganismo empleado, ya sea como cultivo iniciador o secundario, así también como el proceso tecnológico empleado. Abstract Introduction. Since 1990, there has been an increase in the rate of diseases associated with unhealthy diets and sedentary lifestyles, whose care is a challenge for health systems. This has aroused interest in functional foods, i.e., those that in addition to providing macro and micronutrients, provide substances that have a physiological effect on the body, which translates into improving the health of those who ingest them. Generically, these compounds are known as bioactives. Objective. To review the main bioactive substances reported in cheeses, as well as the role of microorganisms in their production and the biosynthetic routes of the main compounds. Development. Milk and its derivatives are food products consumed around the world and show a constant increase in their production and consumption. This market trend is due to its flavor and nutritional value. One of the most demanded dairy products in the world are cheeses. They are a source of substances such as peptides, fatty acids, vitamins, bacteriocins, organic acids, gamma aminobutyric acid, etc. all with important biological activity. Conclusion. The presence, quantity, and availability of the bioactive compounds present in the cheeses differ, as a result of the type of milk used for its elaboration, the type of microorganism used, either as starter or secondary culture, as well as the technological process employed.
- Published
- 2023
8. Bioconservación frente a patógenos de transmisión alimentaria en frutas y hortalizas mínimamente procesadas
- Author
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Isabel Alegre Vilas, Maribel Abadias Seró, Pilar Colás Medà, Cyrelys Collazo Cordero, and Inmaculada Viñas Almenar
- Subjects
cultivos protectores ,bacteriocinas ,bacteriófagos ,iv gama ,seguridad microbiológica ,General Works - Abstract
El aumento en la producción y consumo de frutas y hortalizas mínimamente procesadas de los últimos años ha contribuido a incrementar las toxiinfecciones alimentarias asociadas al consumo de productos vegetales frescos. Esto es debido a que los tratamientos desinfectantes llevados a cabo actualmente por industria de IV gama son insuficientes para garantizar la seguridad microbiológica de los productos finales, y además estos no reciben ningún tratamiento capaz de eliminar todos los patógenos antes de su consumo. Por lo tanto, es necesario utilizar estrategias alternativas para reducir los microorganismos patógenos y alterantes en frutas y hortalizas. La bioconservación, mediante el uso de microorganismos o sus metabolitos, es una alternativa que, en combinación con las prácticas habituales, puede reducir o prevenir el crecimiento de patógenos en productos mínimamente procesados, mejorando su calidad microbiológica. En este artículo se presentan los resultados más relevantes sobre la bioconservación de frutas y hortalizas mínimamente procesadas.
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- 2020
- Full Text
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9. BACTERIOCINOGENIC POTENTIAL OF LACTIC ACID BACTERIA ISOLATED FROM ARTISANAL COLONIAL TYPE-CHEESE.
- Author
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Pegoraro, Kadigia, Jagnow Sereno, Mallu, Quintana Cavicchioli, Valéria, Viana, Cibeli, Augusto Nero, Luís, and dos Santos Bersot, Luciano
- Subjects
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LACTIC acid bacteria , *CHEESE varieties , *PATHOGENIC microorganisms , *BACTERIOCINS , *FOOD conservation , *FOOD production , *GOURMET foods , *BACILLUS cereus - Abstract
Autochthonous microbiota from artisanal cheeses is predominantly composed of lactic acid bacteria (LAB), which are able to produce antimicrobial compounds, such as bacteriocins, suggesting their application in food biopreservation. Knowledge about LAB growth and bacteriocin production during food production and conservation is essential to determine their use. In this way, the study aimed at isolating bacteriocinogenic LAB from twenty-one artisanal Colonialtype cheeses obtained from the western region of Parana state, Brazil, determining the best conditions for growth and bacteriocin production (25°C, 30°C, and 37°C/24h); bacteriocin stability under different ranges of pH (2, 4, 6, 8, and 10 for 2h) and temperature (60oC/2h; 80oC/2h; 121oC/15min). Their activity against different target microorganisms was also evaluated. A total of 34 LAB strains presented characteristics compatible with bacteriocin production. Most of them presented better results for bacteriocin production when cultured at 25°C and 30°C. Bacteriocins remained active against L. monocytogenes when exposed from pH 4 to 8 and a wide temperature range; some bacteriocins were even resistant to sterilization temperatures. Bacteriocins produced were able to inhibit spoilage and pathogenic microorganisms, such as L. monocytogenes, B. cereus, and P. fluorescens. These results indicated that isolated bacteriocinogenic LAB present potential to be used as food biopreservatives. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
10. QUALIDADE HIGIÊNICO-SANITÁRIA DE SUCO DE LARANJA IN NATURA E ESTABELECIMENTOS COMERCIAIS.
- Author
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Adriana Santo, Carla, Louren;co Avelino, Juliana, Messias Souza, Gabrielle, and Kretli Winkelstroter, Lizziane
- Abstract
Current paper analyzes the microbiological quality of in natura orange juice in Presidente Prudente, Brazil, and in commercial establishments. Hygiene and sanitary conditions of work environment was investigated through a check-list and the quality of orange juice was analyzed by plate counts for ANOVA results for non-parameter data (Kruskal-Wallis) at p<0.05. Most commercial establishments had good hygiene practice and thermo-tolerant coliforms were not extant. There were, however, high contaminations in several juice samples. Acidlactic bacteria had counts between 3.15(dp=0.21) and 5.68(dp=0.01) log CFU/mL. Inhibitory evaluation was satisfactory since their impaired Escherichia coli (15 - 27 mm) and Listeria monocytogenes (23 - 27mm). Good practice in hygiene and continued education by food handlers cause a reduction of contamination. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
11. Bioactive compounds in cheeses: biosynthesis, biological activity, and contribution of lactic acid bacteria
- Author
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López Mendoza, Joel, Anaya, Lourdes Adriano, Gálvez López, Didiana, Vázquez Ovando, Alfredo, López Mendoza, Joel, Anaya, Lourdes Adriano, Gálvez López, Didiana, and Vázquez Ovando, Alfredo
- Abstract
Introduction. Since 1990, there has been an increase in the rate of diseases associated with unhealthy diets and sedentary lifestyles, whose care is a challenge for health systems. This has aroused interest in functional foods, i.e., those that in addition to providing macro and micronutrients, provide substances that have a physiological effect on the body, which translates into improving the health of those who ingest them. Generically, these compounds are known as bioactives. Objective. To review the main bioactive substances reported in cheeses, as well as the role of microorganisms in their production and the biosynthetic routes of the main compounds. Development. Milk and its derivatives are food products consumed around the world and show a constant increase in their production and consumption. This market trend is due to its flavor and nutritional value. One of the most demanded dairy products in the world are cheeses. They are a source of substances such as peptides, fatty acids, vitamins, bacteriocins, organic acids, gamma aminobutyric acid, etc. all with important biological activity. Conclusion. The presence, quantity, and availability of the bioactive compounds present in the cheeses differ, as a result of the type of milk used for its elaboration, the type of microorganism used, either as starter or secondary culture, as well as the technological process employed., Introducción. A partir de 1990 se ha observado un incremento en la tasa de enfermedades asociadas con dietas poco saludables y estilos de vida sedentaria, cuya atención supone un reto para los sistemas de salud. Lo anterior, ha despertado el interés por los alimentos funcionales, es decir, aquellos que además de proporcionar macro y micronutrientes, aporten sustancias que poseen efecto fisiológico en el organismo, lo que se traduce en la mejora de la salud de quien lo ingiere. De manera genérica a estos compuestos se les conoce como bioactivos. Objetivo. Revisar las principales sustancias bioactivas reportadas en quesos, el papel de los microorganismos en la producción de las mismas y las rutas de biosíntesis de los principales compuestos. Desarrollo. La leche y sus derivados son productos alimenticios consumidos alrededor del mundo y presentan un incremento constante en su producción y consumo. Esta tendencia de mercado es debida a su sabor y aporte nutrimental. Uno de los derivados lácteos con mayor demanda en el mundo son los quesos. Son una fuente de sustancias como péptidos, ácidos grasos, vitaminas, bacteriocinas, ácidos orgánicos, ácido gamma aminobutírico, etc., todas con importante actividad biológica. Conclusión. La presencia, cantidad y disponibilidad de los compuestos bioactivos presentes en los quesos difiere, como resultado del tipo de leche empleada para su elaboración, el tipo de microorganismo empleado, ya sea como cultivo iniciador o secundario, así también como el proceso tecnológico empleado.
- Published
- 2023
12. Estudio de la respuesta de Lactococcus lactis al daño de la envoltura celular
- Author
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Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Principado de Asturias, Rendueles Martínez, Claudia, Escobedo, Susana, Rodríguez González, Ana, Martínez Fernández, Beatriz, Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Principado de Asturias, Rendueles Martínez, Claudia, Escobedo, Susana, Rodríguez González, Ana, and Martínez Fernández, Beatriz
- Abstract
Lactococcus lactis es el componente mayoritario de los cultivos iniciadores utilizados en la elaboración de productos lácteos fermentados. Durante los procesos industriales de manufacturación, las células de L. lactis están expuestas a condiciones de estrés que comprometen su viabilidad y que en muchas ocasiones tienen impacto sobre la pared celular, una estructura crucial para la supervivencia celular ante condiciones adversas. Dada su relevancia, las bacterias disponen de mecanismos que vigilan su integridad mediante la activación de una respuesta capaz de neutralizar el daño y permitir la adaptación a las nuevas condiciones, y que en su conjunto constituyen lo que se denomina respuesta a estrés celular o respuesta CES (Cell Envelope Stress) En L. lactis la respuesta CES esta mediada por el sistema de dos componentes (TCS) CesSR (ortólogo LiaFSR de Bacillus subtilis), pero en algunas cepas existe además otra ruta de detección y respuesta constituida por un complejo de transducción de señales de tipo Bce, que consta de un sistema TCS y un transportador ABC (TCS-G/YsaDBC). Para dilucidar los mecanismos implicados en la respuesta CES en L. lactis y analizar la posible aplicación de este conocimiento en la generación de cultivos iniciadores robustos con un mayor interés biotecnológico, expusimos un total de siete cepas de L. lactis a concentraciones crecientes de lactococina 972, una bacteriocina específica del género Lactococcus capaz de activar la respuesta CES en L. lactis. De cada una de las siete cepas, tres de origen industrial: L. lactis L81, L62 y L98, y cuatro cepas aisladas en el IPLA (IPLA517, IPLA947, IPLA641 e IPLA1064), se obtuvieron varios mutantes estables resistentes a Lcn972 (Lcn972R) tras la exposición y un proceso de estabilización. Mediante secuenciación y análisis genómico comparativo entre las cepas salvajes y mutantes resistentes, se detectaron un total de 51 mutaciones no sinónimas en 22 genes diferentes, que parecen depender de la cepa parent
- Published
- 2023
13. determinación de bacteriocinas en muestras de consorcios microbianos nativos de ecosistemas de manglar en el departamento del atlántico, como fuente potencial de nuevos tratamientos biomédicos
- Author
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Vanessa Galván Carbonó
- Subjects
bacteriocinas ,saturación ,proteínas ,Medicine - Abstract
Los manglares son ecosistemas con gran diversidad microbiana; la presión de las condiciones físicas de este, se ha relacionado con la producción de metabolitos con estructuras moleculares únicas para los microorganismos. Dado el desarrollo de resistencia bacteriana a antimicrobianos a nivel mundial, se hace necesaria la búsqueda de nuevas soluciones que nos permitan contrarrestar los efectos de dichos patógenos. En este estudio, se buscó aislar, identificar y evaluar la actividad antimicrobiana de bacteriocinas producidas por microorganismos nativos del ecosistema de Manglar de la Ciénaga de Mallorquín, frente a microorganismos patógenos de interés clínico. Se comprobó actividad antimicrobiana leve del extracto CN11, CN 8, P4C3, frente a S. Aureus ATCC 25923, actividad antimicrobiana leve del extracto de P4C3 frente a E. coli BLEE, actividad antimicrobiana leve frente a Klebsiella Pneumoniae ATCC 700603 de los extractos P4C3 y CN9; y actividad antimicrobiana moderada para el caso del extracto proteico de la cepa CN9 frente a E.coli ATCC 25922
- Published
- 2017
- Full Text
- View/download PDF
14. Lactobacillus pentosus en la alimentación animal. Artículo de revisión.
- Author
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Florentino Uña Izquierdo, Ileana Sánchez Ortíz, Redimio Pedraza Olivera, and Amilcar Arenal Cruz
- Subjects
producción de carne ,bacteriocinas ,biosurfactantes ,probióticos ,Animal culture ,SF1-1100 - Abstract
Esta revisión tuvo el objetivo de evaluar la participación de Lactobacillus pentosus en la esfera de la producción de alimentos. Se consultaron revistas especializadas en la producción avícola y otras relacionadas con la producción animal en general, cuyo descriptor principal fue Lactobacillus. Se constató que L. pentosus es una especie versátil encontrada en varios nichos; presentes también en la preparación de muchos alimentos fermentados y en la secreción de diversas sustancias de carácter antimicrobiano. La especie, además, contribuye a disminuir la contaminación ambiental. Existen pocas investigaciones sobre su participación en la producción agropecuaria de carne y aves.
- Published
- 2017
15. Antimicrobial pectin-gellan films: effects on three foodborne pathogens in a meat medium, and selected physical-mechanical properties.
- Author
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Trejo-González, Lorena, Rodríguez-Hernández, Adriana-Inés, del Rocío López-Cuellar, Ma., Juárez-Martínez, Víctor-Manuel, and Chavarría-Hernández, Norberto
- Subjects
- *
FOOD pathogens , *ANTI-infective agents , *PECTINS - Abstract
It is first reported the elaboration and characterization of films (F2) containing 1% (w/v) citrus pectin, 0.2% (w/v) gellan gum, 0.5% (w/v) glycerol, CaCl2 5 mM, ethylenediaminetetraacetic acid (EDTA) 0.05 M and 90 (Arbitrary Units)/mL of an antimicrobial concentrated supernatant (ACS) from fermentation culture broths of the lactic acid bacterium, Streptococcus infantarius. The functional films inhibited the growth of Listeria monocytogenes, Escherichia coli and Staphylococcus aureus in "Barbacoa" medium in 7-day cultures at 35°C. "Barbacoa" is a highly appreciated Mexican meat product. In contrast, the control cultures exhibited bacterial-growths up to 107-109 (Colony-Forming Units)/g. An antimicrobial-activity synergy between ACS and EDTA was demonstrated. Some film-physical properties were modified by the EDTA-ACS incorporation [F2/control-film]: Young's modulus (MPa), 1,394/707; elongation at break (%), 1.9/9.3; stress at break (MPa), 5.7/12.6; water vapor permeability (10-11 g m Pa−1 s−1 m−2), 3/20 and oxygen permeability (10-12 g m Pa−1 s−1 m−2), 1.9/1.2. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
16. Revisão: Aspectos gerais das bacteriocinas
- Author
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Mayara Baptistucci OGAKI, Márcia Cristina FURLANETO, and Luciana Furlaneto MAIA
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Bacteriocinas ,Peptídeos antimicrobianos ,Aplicações industriais ,Bioconservantes ,Nutrition. Foods and food supply ,TX341-641 - Abstract
Resumo Bacteriocinas são peptídeos antimicrobianos sintetizados nos ribossomos, tendo sido descrita uma grande diversidade de bacteriocinas, as quais diferem entre si quanto a composição de aminoácidos, biossíntese, transporte e modo de ação. Nos alimentos, as bacteriocinas podem ser encontradas naturalmente como produtos da microbiota normal ou introduzida (cultura starter ou probióticos). Devido às suas aplicabilidades frente a organismos patogênicos contaminantes em alimentos, vários estudos têm sido publicados, tornando o uso destes peptídeos uma alternativa aos conservantes químicos tradicionais. Considerando-se as propriedades das bacteriocinas e sua potencial aplicação como bioconservadores de alimentos e alternativa aos antibióticos, o presente estudo busca acercar-se de uma visão geral das bacteriocinas quanto aos aspectos históricos, sistemas de classificação, biossíntese e transporte, modo de ação, abordando também algumas de suas aplicações na indústria de alimentos.
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- 2015
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17. Influence of temperature and pH on the production of biosurfactant, bacteriocin and lactic acid by Lactococcus lactis CECT-4434.
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Souza, Ellen Cristina, Azevedo, Pamela Oliveira de Souza de, Domínguez, José Manuel, Converti, Attilio, and Oliveira, Ricardo Pinheiro de Souza
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- *
LACTOCOCCUS lactis , *BIOSURFACTANTS , *BACTERIOCINS - Abstract
Operational conditions such as temperature and pH are well known to influence the production of biosurfactants, bacteriocins, and lactic acid by lactic acid bacteria. The bacterial strainLactococcus lactissubsp.lactisCECT-4434 was used to investigate the effects of temperature (30°C, 37°C and 40°C) and pH control on the production of these biomolecules, in order to establish whether they are able to preferentially address its metabolism towards one product or another. It was observed that the pH control within the range 5.0–5.3 favored the production of lactic acid, which was 38% higher than that obtained without control. The bacteriocin production was higher in the temperature range between 30°C and 37°C, evidenced by the formation of inhibition zones againstLactobacillus sakeiandStaphylococcus aureus, 5–22% and 4–14% higher, respectively, compared with those achieved at 40°C. Finally, the best results for biosurfactant synthesis occurred at 37°C without pH control, with a surface tension reduction between 22.5 and 24.7 mN/m after 6–24 h of culture, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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18. EFECTO DE FACTORES EXTRINSECOS SOBRE LA ACTIVIDAD ANTIMICROBIANA DEL METABOLITO W10b PRODUCIDO POR Weissella confusa
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LILIANA SERNA-COCK, LEIDY JOHANA VALENCIA H, and ANGELA VIVIANA RUALES S
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Bacteriocinas ,Bacteria ácido Láctica ,Staphylococcus aureus ,Streptococcus agalactiae ,Agriculture (General) ,S1-972 ,Biotechnology ,TP248.13-248.65 - Abstract
Las bacterias ácido lácticas producen sustancias antimicrobianas que pueden perder su actividad debido a factores extrínsecos. En este estudio se determinaron los efectos de temperatura, pH, tiempo de exposición y enzimas sobre la actividad antimicrobiana del metabolito W10b producido por la bacteria ácido láctica Weissella confusa. W10b es activo contra Staphylococcus aureus y Streptococcus agalactiae. W. confusa se produjo mediante fermentación a 32°C por 4 horas y el metabolito W10b se obtuvo a partir del sobrenadante libre de células mediante centrifugación, filtración y liofilización. W10b se sometió a pH ácido, neutro y básico, para dos tiempos de exposición (10 y 30 minutos) y diferentes temperaturas (27, 40, 60 y 100°C). Además se midió el efecto de las enzimas pepsina y amiloglucosidasa sobre W10b. Se encontró diferencias significativas (p
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- 2014
19. Evaluation of the antimicrobial effect of a probiotic mixture against Cronobactersakazakii and Salmonellaenterica in infant formulas
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C. Candel-Pérez, J. García-Alonso, R. García-Iborra, and Mª Carmen Martínez-Gracia
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Preparados para lactantes ,6 - Ciencias aplicadas::63 - Agricultura. Silvicultura. Zootecnia. Caza. Pesca [CDU] ,Salmonella ,biology ,Salmonella enterica ,General Medicine ,biology.organism_classification ,medicine.disease_cause ,Cronobacter sakazakii ,Follow-on infant formula ,Microbiology ,Incubation temperature ,Lactobacillus rhamnosus ,Antimicrobial effect ,medicine ,Bifidobacterium infantis ,Bi-fidobacterium infantis ,Bacteriocinas - Abstract
Cronobacter sakazakii y Salmonella enterica son considerados patógenos capaces de causar sepsis y meningitis en lactantes. Se han descrito casos de infección por estos patógenos asociados al consumo de preparados para lactantes contaminados. La inclusión de probióticos en los preparados, además de su papel en la modulación de la microbiota intestinal, podría ser útil para contrarrestar la contaminación de microorganismos patógenos de estos productos una vez reconstituidos y, por lo tanto, reducir el riesgo de infección. El objetivo de esta investigación fue evaluar el efecto antimicrobiano de una mezcla de probióticos (Lactobacillus rhamnosus y Bifidobacterium infantis) frente a Cronobacter sakazakii y Salmonella enterica en preparados reconstituidos para lactantes. Las muestras (con o sin probióticos) se inocularon con C. sakazakii o S. enterica y se incubaron a 30 o 40ºC durante 72 horas. Los resultados muestran que la presencia de probióticos en los preparados lácteos no tiene un marcado efecto en el crecimiento de los patógenos. Sin embargo sí se ve potenciado su efecto inhibitorio frente a C. sakazakii por la interacción entre la temperatura de incubación y los probióticos. Los probióticos empleados fueron viables durante todo el período de incubación, por lo que el agotamiento de los nutrientes se descartó como posible mecanismo de inhibición. La disminución del pH en los preparados lácteos inoculados no explica de manera satisfactoria un comportamiento tan diferente entre ambos patógenos. Por lo tanto, se sugiere como posible mecanismo inhibidor la liberación de bacteriocinas específicas con acción contra C. sakazakii pero sin efecto contra Salmonella. Se deben realizar estudios adicionales para probar esta hipótesis. Cronobacter sakazakii and Salmonella enterica have been implicated in outbreaks causing sepsis and meningitis in infants. Several infection cases have been associated with the consumption of contaminated powdered infant formulae. Besides its role in modulating gut microbiota, the inclusion of probiotics in infant formulae may be useful to counteract pathogen contamination in these products and thus to reduce the risk of infection. The aim of this research was to evaluate the antimicrobial effect of a mixture of the probiotics Lactobacillus rhamnosus and Bifidobacterium infantis against Cronobacter sakazakii and Salmonella enterica in reconstituted follow-on formulae. For that, infant formulae (with or without probiotics) were inoculated with either C. sakazakii or S. enterica and incubated at 30 or 40ºC for 72 hours. Overall, the results showed the presence of probiotics inhibiting the growth of C. sakazakii together with incubation temperature (interaction between both factors). Probiotics were viable throughout the incubation period so that nutrient exhaustion could be ruled out as the mechanism of C. sakazakii inhibition. Thus, the acidification of media observed during the study was hypothesized to be responsible for pathogen growth inhibition. However, since in the case of formulae inoculated with Salmonella the behavior of probiotics and pH values was similar to C. sakazakii, the decrease of pH does not satisfactorily explain such a different behavior. So, it is suggested that the production of specific bacteriocins by probiotics against C. sakazakii but not against Salmonellla could be the underlying inhibitory mechanism. Further studies should be carried out to test this hypothesis.
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- 2020
20. Lactobacillus pentosus en la alimentación animal. Artículo de revisión.
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Uña Izquierdo, Florentino, Sánchez Ortíz, Ileana, Pedraza Olivera, Redimio, and Arenal Cruz, Amilcar
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LACTOBACILLUS , *ANIMAL feeding , *ANIMAL feeds , *BACTERIOCINS , *MEAT industry , *BIOSURFACTANTS , *PROBIOTICS - Abstract
This review aimed to assess the involvement of Lactobacillus pentosus in the field of food production. Journals specialized in poultry and animal production in general were reviewed. The main descriptor used was Lactobacillus. It was found that L. pentosus is a versatile species found in a variety of environmental niches, which has a significant presence in the preparation of many fermented foods; also in the secretion of various substances of antimicrobial character, and it contributes to reduce environmental pollution. There are very few researches on the participation of L. pentosus in the agricultural production of meat and poultry. [ABSTRACT FROM AUTHOR]
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- 2017
21. ADICION DE Carnobacterium maltaromaticum CB1 EN CHORIZO Y MORCILLA EMPACADOS AL VACIO, PARA INHIBIR EL CRECIMIENTO DE Listeria monocytogenes
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María I. GONZALEZ H., Wan YIEN, Jorge A. CASTRILLON V., and Ángela ORTEGA P.
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Biotecnología ,Carnobacterium ,bacteriocinas ,productos cárnicos ,Food processing and manufacture ,TP368-456 ,Pharmaceutical industry ,HD9665-9675 - Abstract
Antecedentes: En años recientes la demanda de productos alimenticios percibidos como ''naturales'' se ha incrementado de manera importante, los cuales no contienen dentro de sus ingredientes conservantes o aditivos de origen químico o artificial. Al retirar de la fórmula estos conservantes/aditivos artificiales se puede generar en el producto un medio ideal de crecimiento de bacterias alterantes o patógenas. Esto es particularmente cierto en productos cárnicos procesados empacados al vacío, donde su alta actividad acuosa, bajo pH y un largo periodo de almacenamiento a condiciones de refrigeración generan un ambiente ideal para el crecimiento de microorganismos patógenos como Listeria monocytogenes. Por tanto, esto genera la necesidad de nuevas y efectivas tecnologías que permitan su control y eliminación. Los Bio-Conservantes (adición de bacterias vivas a los productos cárnicos) ofrecen una solución ideal a este tipo de problemas directamente relacionados con la seguridad alimentaria, y a la vez satisfacen la demanda por parte de los consumidores de productos saludables. Objetivos: Determinar si el cultivo C. maltaromaticum CB1 puede controlar el crecimiento de una cepa nativa de L. monocytogenes en morcilla y chorizo empacados al vacío (película de baja permeabilidad al oxigeno). Métodos: Tres lotes diferentes de chorizo y morcilla producidos a nivel industrial fueron posteriormente inoculados con una cepa nativa de L. monocytogenes a un nivel de 10² UFC/g junto con el bio-conservante C. maltaromaticum CB1 a un nivel de 10³ UFC/g. A los tratamientos denominados como control no se les aplicó el bio-conservante. Después de ser empacados al vacío, los productos fueron almacenados a dos temperaturas diferentes de 4°C (refrigeración) y 8°C (abuso de temperatura) durante 35 días. En intervalos de 7 días se hizo recuentos del crecimiento de la L. monocytogenes utilizando agar Oxford. Resultados: Se obtuvo una reducción significativa (P < 0.05) en los recuentos de L. monocytogenes tanto en la morcilla como en el chorizo tratados con bio-conservante C. maltaromaticum CB1 y almacenados a 4°C y 8°C respectivamente, en comparación con los productos denominados control. Conclusiones: La cepa de C. maltaromaticum CB1 demostró ser efectiva en el control del crecimiento de la cepa nativa de L. monocytogenes en chorizo y morcilla.
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- 2013
22. Caracterização da função do sistema scwdABC de Staphylococcus aureus em interações inter-espécie e com o hospedeiro
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Silva, Miguel Ângelo Patinho, Sobral, Rita, and Portela, Raquel
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Internalização em Macrófagos ,Staphylococcus aureus ,Biossíntese de Peptidoglicano ,Engenharia e Tecnologia::Outras Engenharias e Tecnologias [Domínio/Área Científica] ,Bacteriocinas ,Formação de Biofilme - Abstract
Em estudos anteriores sobre o gene murF de Staphylococcus aureus, responsável pela adição do terminal D-alanil-D-alanina do pentapéptido do peptidoglicano, verificou-se que a sua interrupção, no mutante de inserção F9, levava à anormal incorporação de tripéptido na parede, apesar da sua viabili- dade e taxa de crescimento não serem afetadas. A análise transcriptómica deste mutante revelou a exis- tência de um sistema sobreexpresso, constituído por dois genes de função desconhecida, scwdA e scwdB, e um gene que codifica uma proteína transmembranar, scwdC. Resultados preliminares mostra- ram que estas proteínas têm um papel no fitness de S. aureus aquando da presença de danos na parede e sugerem que ScwdA-B se associam a membranas biológicas através de hélices-α anfipáticas. A hipó- tese colocada é que a expressão das proteínas ScwdA-B seja desencadeada pelo dano na parede, sendo secretadas pela ScwdC, e atuem como bacteriocinas contra outras bactérias ou no hospedeiro. Esta tese teve como objetivo caracterizar o papel do sistema scwdABC em interações inter- espécie e com o hospedeiro. As proteínas ScwdA e ScwdB recombinantes foram expressas e purificadas como fusões His- tag, tendo estes processos sido otimizados. Quanto à localização, os resultados mostraram uma possível associação entre as proteínas ScwdA-B e a membrana celular de Escherichia coli, quando estas proteí- nas são sobreexpressas heterologamente por E. coli. A sobreexpressão de ScwdC na presença de tampão fosfato afetou negativamente o crescimento de S. aureus, um efeito que foi acentuado pelo aumento de concentração de fosfato, e foi revertido na presença de ScwdB, revelando um possível papel no fitness da bactéria em condições de stress. As proteínas, isoladamente, bem como o meio de cultura dos mu- tantes de sobreexpressão não apresentaram atividade antimicrobiana contra as espécies bacterianas e estirpes de S. aureus estudadas, não sendo possível concluir quanto à sua atividade como bacteriocinas. Adicionalmente, os resultados não mostraram uma correlação entre os genes scwdA-B e a capacidade de formação de biofilme. No entanto, a sua sobreexpressão resultou num aumento da internalização de S. aureus em macrófagos. revelando um possível papel de ScwdA-B na interação com o hospedeiro. Previous studies on the Staphylococcus aureus murF gene, responsible for the addition of the D- alanyl-D-alanine terminus of the peptidoglycan pentapeptide, showed that its interruption, in the F9 insertion mutant, led to the abnormal incorporation of tripeptide into the cell wall, although its viability and growth rate were not affected. The transcriptomic analysis of this mutant revealed the overexpres- sion of a genetic system, constituted by two genes of unknown function, scwdA-B, and a gene encoding a transmembrane protein, scwdC. Preliminary results showed a role for these proteins in the fitness of S. aureus in the presence of a cell wall damage and a possible association between ScwdA-B and bio- logical membranes through amphipathic α-helices. The hypothesis raised is that the expression of ScwdA-B proteins is triggered by a damage to the wall, being both proteins secreted, possibly by ScwdC, and acting as bacteriocins on other bacteria or on the host. The aim of this thesis was to characterize the role of the scwdABC system in inter-species and host interactions. ScwdA and ScwdB recombinant proteins were expressed and purified as His-tag fusions and these processes were optimized. The results showed a possible association between the ScwdA-B pro- teins and Escherichia coli cell membrane, when the proteins were heterologously expressed by E. coli. The overexpression of ScwdC in the presence of increasing concentrations of phosphate buffer nega- tively affected the growth of S. aureus, and this effect was reversed in the presence of ScwdB, revealing a possible role of ScwdB in the fitness of the bacteria under stress conditions. The proteins alone, as well as the spent medium of the overexpression mutants did not show antimicrobial activity against the studied bacterial species and S. aureus mutant strains, thus it was not possible to conclude on their activity as bacteriocins. Additionally, the results did not show a correlation between scwdA-B genes and the capacity to form biofilm. However, their overexpression was shown to increase the internaliza- tion of S. aureus into macrophages, revealing a possible role of ScwdA-B in host interaction.
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- 2022
23. Growth and antimicrobial activity of lactic acid bacteria from rumen fluid according to energy or nitrogen source Crescimento e atividade antimicrobiana de bactérias ácido-láticas do líquido ruminal de acordo com a fonte de energia ou de compostos nitrogenados
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Isabela Pena Carvalho de Carvalho, Edenio Detmann, Hilário Cuquetto Mantovani, Mário Fonseca Paulino, Sebastião de Campos Valadares Filho, Viviane Aparecida Carli Costa, and Daiany Iris Gomes
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bacteriocinas ,celulose ,efeito proteína ,microbiologia do rúmen ,bacteriocin ,cellulose ,protein effect ,rumen microbiology ,Animal culture ,SF1-1100 - Abstract
The objective of this study was to evaluate the effects of supplementation with different sources of energy and nitrogenous compounds on the in vitro growth and production of bacteriocin of lactic acid bacteria. Incubations were performed by using ruminal fluid from a rumen-fistulated Holstein-Zebu steer. The animal was kept on a Brachiaria decumbens pasture receiving 200 g/day of supplemental crude protein. Substrates and inoculum were placed in glass flasks considering eight treatments: cellulose, cellulose and casein, cellulose and soy peptone, cellulose and urea, starch, starch and casein, starch and soy peptone and starch and urea. Successive incubations were conducted to select microorganisms according to the energy sources and nitrogenous compounds. Starch favoured growth of lactic acid bacteria when compared to cellulose. Supplementation with true protein (soy peptone and casein) stimulated the growth of these bacteria when compared to the control (without supplementation with nitrogenous compounds). The addition of urea did not stimulate the growth of lactic acid bacteria. No antimicrobial activity was detected from colonies of isolated lactic acid bacteria. Sources of true protein increase the competition between non-structural and structural carbohydrates fermenting bacteria.Objetivou-se avaliar os efeitos da suplementação com diferentes fontes de energia e de compostos nitrogenados sobre o crescimento e produção de bacteriocinas de bactérias ácido-láticas in vitro. As incubações foram conduzidas utilizando-se fluido ruminal originado de um novilho Holandês-Zebu fistulado no rúmen. O animal foi mantido em pastagem de Brachiaria decumbens recebendo 200 g/dia de proteína bruta suplementar. Os substratos e o inóculo foram acondicionados em frascos de vidro considerando-se oito tratamentos: celulose, celulose e caseína, celulose e peptona de soja, celulose e ureia, amido, amido e caseína, amido e peptona de soja e amido e ureia. Incubações sucessivas foram conduzidas para seleção dos microrganismos em função das fontes energéticas e de compostos nitrogenados. O amido favoreceu o crescimento de bactérias ácido-láticas em comparação à celulose. A suplementação com proteína verdadeira (peptona de soja e caseína) estimulou o crescimento dessas bactérias em comparação ao controle (sem suplementação com compostos nitrogenados). A adição de ureia não estimulou o crescimento de bactérias ácido-láticas. Nenhuma atividade antimicrobiana foi detectada a partir das colônias de bactérias ácido-láticas isoladas. Fontes de proteína verdadeira incrementam a competição entre bactérias fermentadoras de carboidratos estruturais e não-estruturais.
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- 2011
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24. EFECTO DEL EXTRACTO CRUDO DE BACTERIOCINAS SOBRE LAS CARACTERÍSTICAS MICROBIOLÓGICAS Y SENSORIALES DE SOLOMO REDONDO (Longissimus dorsi) EMPACADO AL VACÍO CRUDE BACTERIOCIN EXTRACT EFFECT ON THE MICROBIOLOGICAL AND SENSORIAL CHARACTERISTICS OF SOLOMO REDONDO (Longissimus dorsi) VACUUM-PACKAGING
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Sandra M VÁSQUEZ, Héctor SUÁREZ M, and Olga I MONTOYA C
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biopreservación ,Longissimus dorsi ,bacteriocinas ,Lactobacillus plantarum LPBM10 ,empaque al vacío ,biopreservation ,bacteriocin ,vacuum packaging ,Food processing and manufacture ,TP368-456 ,Pharmaceutical industry ,HD9665-9675 - Abstract
Se evalúa la aplicación de extracto crudo de bacteriocinas (ECB), producido por Lactobacillus plantarum LPBM10 sobre las características microbiológicas y sensoriales de filetes de solomo redondo (Longissimus dorsi) empacado al vacío, durante 31 días de almacenamiento a 3°C. Se realizan análisis microbiológicos, de pH, fuerza de corte, pérdida de peso y análisis sensorial. Los resultados presentan diferencias significativas en conteos de psicrotrófilos en el quinto día de almacenamiento, siendo mejor el tratamiento con ECB que el que se sigue con ácido láctico pH 5.74. Los valores de coliformes fecales estuvieron alrededor de 1.5 NMP/g en las muestras de carne con ECB registrando diferencias significativas en todos los días de almacenamiento (pThe application of crude bacteriocins extract (CBE) produced by Lactobacillus plantarum LPBM10 is tested on the microbiological and sensory characteristics of rib filets (Longissimus dorsi) vacuum packing for 31 days storage at 3°C. As parameters of meat quality through time microbiology analysis, pH, cutting force, weight loss and sensorial are made. Significant differences are found in psychrotrophic counts in the fifth day storage, being better the treatment with crude bacteriocin extract. Levels of fecal coliforms persist around 1.5 UFC/g in meat samples with crude bacteriocins extract. Significant difference in every day storage (p
- Published
- 2009
25. BACTERIOCINAS E ENZIMAS PRODUZIDAS POR Bacillus spp. PARA CONSERVAÇÃO E PROCESSAMENTO DE ALIMENTOS
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D. SCHULZ, R. R. BONELLI, and C. R.V. BATISTA
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Bacteriocinas ,enzimas ,Bacillus spp. ,alimentos ,Nutrition. Foods and food supply ,TX341-641 - Abstract
Alguns microrganismos possuem a capacidade de produzir substâncias que podem influenciar no desenvolvimento de outros microrganismos. Desde os anos 50 é relatada a capacidade de várias espécies de bactérias do gênero Bacillus de produzir substâncias com atividade antimicrobiana como peptÃdeos, também denominados de bacteriocinas e enzimas como a subtilisina, subtilina, as proteases e as termolisinas. Muitos desses peptÃdeos e enzimas têm sido caracterizados bioquimicamente e geneticamente. Embora sejam conhecidas, a função estrutural, a biossÃntese e modo de ação de alguns peptÃdeos antimicrobianos e enzimas, muitos aspectos desses compostos ainda permanecem desconhecidos. Esse artigo descreve uma revisão sobre as principais bacteriocinas e enzimas produzidas por Bacillus spp., bem como suas aplicações em alimentos. Alguns dados de segurança de bacteriocinas e enzimas produzidas por Bacillus spp. também são relatados. PALAVRAS-CHAVE: Bacteriocinas; enzimas; Bacillus spp.; alimentos.
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- 2009
26. Aislamiento de Lactobacillus plantarum LPBM10 y caracterización parcial de su bacteriocina Isolation of Lactobacillus plantarum LPBM10 and partial characterization of its bacteriocin
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Sandra ZAPATA, Juliana MUÑOZ, Orlando S RUIZ, Olga I MONTOYA, and Pablo A GUTIÉRREZ
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Lactobacillus plantarum ,Bacteriocinas ,Antimicrobianos ,Bacteriocins ,Antimicrobials ,Food processing and manufacture ,TP368-456 ,Pharmaceutical industry ,HD9665-9675 - Abstract
Las bacterias acidolácticas (BAL) son un grupo de microorganismos Gram positivos utilizados ampliamente en la preservación de alimentos debido a sus propiedades probióticas y su capacidad para producir bacteriocinas. Las bacteriocinas son compuestos antimicrobianos de naturaleza peptídica y han recibido gran atención por la industria de alimentos debido a su uso potencial como sustitutos de aditivos químicos. En este trabajo reportamos el aislamiento y caracterización de la cepa de Lactobacillus plantarum LPBM10. Esta bacteria fue aislada a partir de leche fermentada, presenta propiedades probióticas y es productora de bacteriocinas. El extracto libre de células de LPBM10 presenta actividad antimicrobiana frente a bacterias Gram positivas y Gram negativas. La bacteriocina LPBM10 es altamente termoestable, presenta mayor actividad a pH ácido y su actividad no se ve afectada por la presencia de proteinasa K, agentes quelantes y detergentes. El compuesto antibacteriano LPBM10 fue purificado mediante diálisis y cromatografía de exclusión. El análisis por espectroscopía ultravioleta e infrarroja sugiere que la bacteriocina LPBM10 es de naturaleza peptídica con presencia de tirosina y cisteína. Pruebas sobre el extracto crudo dializado mediante cromatografía de intercambio iónico indican la presencia de un compuesto aniónico antagonista del compuesto LPBM10.Lactic acid bacteria are a group of Gram-positive microorganisms widely used in food preservation due to their probiotic properties and their ability to produce bacteriocins. Bacteriocins are antibiotic compounds of peptide nature which have been studied intensively for their potential use as substitutes of chemical additives in food preservation. In this paper we report the isolation and characterization of Lactobacillus plantarum LPBM10. This bacteriocin was isolated from fermented milk and can be classified as probiotic. The free cell extract was active against Gram positive and Gram negative bacteria. This bacteriocin is highly thermostable, active at low pH and its activity is not affected by proteinase K, chelating agents and detergents. This antibiotic compound was purified by dyalisis and size exclusion chromatography. Its analysis by UV and FT-IR spectroscopy suggests that bacteriocin is a peptide containing some cystein and tyrosine aminoacids. Experiments on dyalized crude extract by ion-exchange chromatography suggest the presence of an anionic inhibitor of LPBM10.
- Published
- 2009
27. CARACTERIZACIÓN PRELIMINAR DE COMPUESTOS ANTILISTERIALES PRODUCIDOS POR BACTERIAS ÁCIDO LÁCTICAS NATIVAS
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Blanca Botina A, Barbara H. Zimmermann, and María Vanegas L
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Bacterias ácido lácticas ,L. monocytogenes ,antagonismo ,bacteriocinas ,Veterinary medicine ,SF600-1100 - Abstract
Objetivo. Caracterizar los metabolitos producidos por bacterias ácido lácticas nativas con capacidad antilisterial. Materiales y métodos. Se analizaron 42 muestras tomadas de alimentos y equipos procesadores de alimentos, de donde se aislaron bacterias ácido lácticas, las cuales se identificaron por medio de pruebas bioquímicas. Se evaluó la actividad antagónica de las cepas aisladas frente a 17 cepas de L. monocytogenes pertenecientes a los serotipos 4b, 4e, y 3b utilizando la técnica de la gota y doble capa. Se obtuvieron extractos crudos para la caracterización de los metabolitos inhibitorios del crecimiento de las cepas de L. monocytogenes, los cuales fueron tratados con catalasa, ácido clorhídrico, proteinasa K y temperaturas de 95ºC y 121ºC. El peso molecular de las proteínas se aproximó utilizando la técnica de electroforesis SDS-PAGE y bioensayos. Resultados. De un total de 250 aislamientos se lograron identificar 75 cepas de bacterias ácido lácticas. La evaluación de la actividad antagónica indicó que los metabolitos inhibitorios producidos por las bacterias ácido lácticas no actuaban de igual manera frente a las diferentes cepas de L. monocytogenes. Sin embargo, se encontró que tres de los aislamientos nativos identificados como Lactobacillus spp., Leuconostoc spp. y Enterococcus spp. presentaban una mejor actividad antilisterial debido a que sintetizan proteínas o metabolitos de peso molecular menor a 7600 Da. Conclusiones. En los alimentos distribuidos en Colombia existen cepas de bacterias ácido lácticas con potencial bioprotector.
- Published
- 2008
28. INFLUENCIA DE BACTERIOCINAS PRODUCIDAS POR Lactobacillus plantarum LPBM10 SOBRE LA VIDA ÚTIL DE FILETES DEL HÍBRIDO DE CACHAMA Piaractus brachypomus x Colossoma macropomum EMPACADO AL VACÍO: INFLUENCE OF BACTERIOCINS PRODUCED BY Lactobacillus plantarum LPBM10 ON SHELF LIFE OF CACHAMA HYBRID FILLETS Piaractus rachypomus x Colossoma macropomum VACUUM PACKAGED
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Héctor SUÁREZ M, Alicia de FRANCISCO, and Luiz H BEIRÃO
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bacteriocinas ,peces ,Lactobacillus plantarum LPBM10 ,acuicultura ,vida útil ,bacteriocins ,fish ,aquaculture ,shelf life ,Food processing and manufacture ,TP368-456 ,Pharmaceutical industry ,HD9665-9675 - Abstract
El uso de algunos de los géneros de las bacterias ácidolácticas (BAL) como Lactobacillus, Leuconostoc, Lactococcus, o sus productos antimicrobianos como las bacteriocinas, son alternativas en la biopreservación de productos mínimamente procesados que son mantenidos bajo refrigeración. El potencial de biopreservación de un extracto crudo de bacteriocinas producidas por una cepa nativa de Lactobacillus plantarum LPBM10, se evalúa sobre filetes de híbrido de cachama Piaractus brachypomus x Colossoma macropomum empacados al vacío durante 30 días de almacenamiento a 3±0,5 0C. La evaluación se realiza por medio del recuento: mesófilos (heterótrofos), psicrófilos, esporas sulfitoreductoras, coliformes totales y fecales y presencia de Salmonella, teniendo en cuenta tres tratamientos: extracto crudo de bacteriocinas, ácido láctico y el control. El recuento de heterótrofos no presenta diferencia entre los tratamientos, mientras el recuento de psicrotrófilos alcanza valores de 5.2 ciclos log, 6.7 ciclos log y 6.4 ciclos log (PSome lactic acid bacteria genera (BAL) as Lactobacillus, Leuconostoc, Lactococcus or their antimicrobial products as bacteriocins are used as alternatives biopreservation of minimally processed foods kept under refrigeration. Potential Biopreservatives from a bacteriocin producer native strain, Lactobacillus plantarum LPBM10, was evaluated on fillets of cachama hybrid Piaractus brachypomus x Colossoma macropomum, vacuum-packed and stored at 30±0,5°C during 30 days. The evaluation was undertaken using three treatments, bacteriocins raw extract, lactic acid and control. There were not differences among treatments on Mesophylls count. Meanwhile, psychotrophylls count reached values for fillets treated with raw extract of bacteriocins, lactic acid and control, 5.2 cycles log, 6.7 cycles log and 6.4 cycles log (P
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- 2008
29. Lactococcus lactis autóctono: evaluación del efecto antilisterial y de propiedades sensoriales en quesos tipo Cuartirolo.
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González Revello, Álvaro, Carro, Silvana, Cal, Karina, Giacaman, Sheila, and Aldrovandi, Ariel
- Abstract
Copyright of Innotec is the property of Laboratorio Tecnologico del Uruguay and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2016
30. Antilisterial activity and physical-mechanical properties of bioactive caseinate films.
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Calderón-Aguirre, Ángel-Guadalupe, Chavarría-Hernández, Norberto, Mendoza-Mendoza, Bethsua, Vargas-Torres, Apolonio, García-Hernández, Edgar, and Rodríguez-Hernández, Adriana-Inés
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ANTI-infective agents , *ACTIVE food packaging , *STREPTOCOCCUS , *LISTERIA monocytogenes , *BACTERIOCINS , *PERMEABILITY , *NISIN - Abstract
Antimicrobial films were formulated with sodium caseinate (C), glycerol and antimicrobial substances (AM) produced byStreptococcus infantarius.The antilisterial activity of the films was evaluated usingListeria monocytogenesas test microorganism and two incubation conditions: T = 35°C, 32 ± 10% RH and T = 4°C, 98 ± 10% RH. A comparison of the antimicrobial action was made with caseinate films carrying equivalent activity units of commercial nisin (Nis). At 35°C and 32% RH, AM increased the lag-phase and inhibited 80% of the growth ofL. monocytogenes. At 4°C and 98% RH, C-Nis and C-AM films extended the lag-phase of the bacterial growth up to 11 and 38 days, respectively. AM showed a higher antilisterial effect than nisin at both incubation conditions. The incorporation of AM or Nis did not produce significant differences in the barrier properties of the films, but AM acted as an additional plasticizer into the films. [ABSTRACT FROM AUTHOR]
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- 2015
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31. Screening and characterization of bacteriocins produced by bacteria against Escherichia coli and Staphylococcus aureus
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Yenush, Lynne Paula, Diep, Dzung Bao, Universitat Politècnica de València. Departamento de Biotecnología - Departament de Biotecnologia, Universitat Politècnica de València. Escuela Técnica Superior de Ingeniería Agronómica y del Medio Natural - Escola Tècnica Superior d'Enginyeria Agronòmica i del Medi Natural, Casado García-Consuegra, Zulema, Yenush, Lynne Paula, Diep, Dzung Bao, Universitat Politècnica de València. Departamento de Biotecnología - Departament de Biotecnologia, Universitat Politècnica de València. Escuela Técnica Superior de Ingeniería Agronómica y del Medio Natural - Escola Tècnica Superior d'Enginyeria Agronòmica i del Medi Natural, and Casado García-Consuegra, Zulema
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[ES] En los últimos años, la aparición de bacterias resistentes a los antibióticos se ha convertido en una amenaza mundial debido al mal uso y abuso de estas sustancias en el tratamiento de enfermedades animales y humanas. Por este motivo, tratamientos convencionales para ciertas patologías han perdido total o parcialmente su efectividad. Además, la presencia de antibióticos en el medio ambiente tiene un impacto de larga duración que incrementa la incidencia de resistencias. Con el objetivo de controlar esta crisis emergente, las bacteriocinas se consideran una alternativa plausible ya que son capaces de matar a las bacterias resistentes mediante un mecanismo de acción que difiere del que presentan los antibióticos convencionales. Las bacteriocinas son proteínas biológicamente activas sintetizadas por las bacterias y secretadas al medio extracelular, donde presentan actividad antimicrobiana contra otras bacterias. Concretamente, las bacteriocinas producidas por bacterias ácido-lácticas son especialmente interesantes ya que son reconocidas como seguras (GRAS), y no presentan toxicidad en humanos debido a que son degradadas por proteasas en el tracto intestinal. El objetivo de nuestro estudio es aislar, caracterizar y purificar bacteriocinas ácido-lácticas que puedan inhibir al patógeno Gram negativo de origen alimentario Escherichia coli., [EN] In recent years, bacterial antibiotic resistance has become a worldwide hazard due to the misuse and abuse of antibiotics in the treatment of animal and human disorders. The emergence of resistant bacteria leads some conventional treatments to lose partial or total effectiveness. Moreover, the leaking of antibiotics into the environment has a long-lasting impact which increases the incidence of resistances. To control the resistance crisis, bacteriocins are considered one plausible alternative because may kill antibiotic-resistant bacteria using a different killing mechanism than antibiotics. Bacteriocins are proteins biologically active from bacteria, which are secreted to the extracellular medium, and have an antimicrobial action against other bacteria. Concretely, bacteriocins produced by lactic acid bacteria are specially interesting because they are generally recognized as safe (GRAS), and have no toxicity in humans since they are degraded by proteases in the intestinal tract. The purpose of our study is to isolate, characterize, and purify lactic acid bacteriocins which may inhibit the Gram-negative foodborne pathogen Escherichia coli.
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- 2021
32. Characterization of the lactic microbiota of Minas artisanal Cheese produced in the region of Serro, Minas Gerais, by dependent and independent culture methods
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Ferreira, Letícia Rocha and Nero, Luís Augusto
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Microbiologia de Alimentos ,Microbiota ,Queijo-de-minas - Microbiologia ,Bacteriocinas - Abstract
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Queijos Minas artesanais (QMA) possuem importância social, econômica e cultural para inúmeras famílias de produtores rurais. QMA são tradicionalmente produzidos em várias regiões de Minas Gerais com leite cru e fermento endógeno, “pingo”, derivado de sua dessoragem. Além da produção tradicional, alguns produtores da região do Serro utilizam “rala” como fermento endógeno, obtida pela raspagem do QMA após 3-5 dias de fabricação. A alteração do fermento endógeno pode levar a alterações da microbiota do QMA, incluindo a microbiota lática que exerce papel fundamental na produção, maturação, desenvolvimento de características sensoriais, bioconservação e inocuidade. O conhecimento da microbiota lática autóctone do QMA auxilia na caracterização de sua identidade, permitindo sua consolidação como símbolo regional. O estudo da microbiota de alimentos fermentados usualmente é realizado por métodos cultura-dependentes, limitados pela microbiota complexa e pelo cultivo de parte da microbiota. Como alternativa, métodos cultura-independentes têm sido cada vez mais utilizados; esses métodos também possuem algumas limitações, como dificuldade de diferenciação entre microrganismos viáveis e não viáveis. A abordagem ideal para a caracterização da microbiota de queijos artesanais é a associação de métodos cultura- dependentes e -independentes de cultivo. Esse estudo teve como objetivo caracterizar a microbiota lática autóctone do QMA do Serro com diferentes características de produção por métodos cultura-dependentes e -independentes de cultivo. Amostras de QMA do Serro (n = 55) foram obtidas na Cooperativa dos Produtores Rurais do Serro (CooperSerro) e caracterizadas quanto ao fermento endógeno (“pingo” e “rala”), cidade produtora (Alvorada de Minas, Sabinópolis, Santo Antônio do Imbé, Serra Azul de Minas e Serro), tamanho da fazenda produtora (produção diária de leite) e tempo de produção (dias). As amostras foram submetidas a enumeração de bactérias ácido láticas (BAL) em ágar MRS, pH 5,7 e obtenção de isolados (n = 176) que foram caracterizados por Repetitive extragenic palindromic-PCR (Rep-PCR) e identificados por sequenciamento da região V1-V3 do 16S rRNA. Em paralelo, as amostras foram submetidas a extração de DNA total para caracterização da diversidade microbiana por Rep-PCR, Denaturing Gradient Gel Eletrophoresis (DGGE) e sequenciamento da região V3-V4 do 16S rRNA. A contagem de BAL em amostras e QMA do Serro variaram entre 5,4 e 8,4 log UFC/g com um valor médio de 6,9 log UFC/g, e os principais grupos/gêneros identificados foram lactobacilos, Lactococcus lactis e Enterococcus sp.; não foram identificadas tendências nas contagens e distribuição de BAL considerando as características das amostras. Rep-PCR identificou semelhanças intraespécies superiores a 75%. O sequenciamento das bandas de DGGE identificou a prevalência de L. lactis em todas as amostras, além de Streptococcus salivarius. Considerando o DNA total das amostras, L. lactis foi identificado como espécie dominante em todas as amostras. Rep-PCR e DGGE provaram ser ferramentas úteis para estudar a microbiota lática de queijos artesanais. A abordagem integrada dos métodos cultura- dependente e -independente forneceu uma descrição mais detalhada da diversidade lática presente no QMA do Serro. A microbiota lática do QMA do Serro possui uma composição estável, sem variações evidentes considerando as características de produção avaliadas. Palavras-chave: Bactérias ácido láticas. Pingo. Rala. Cultura-dependente. Cultura-independente. Sequenciamento. Minas artisanal cheeses (MAC) have social, economic and cultural importance for countless rural producer families. MAC are traditionally produced in several regions of Minas Gerais with raw milk and endogenous starter, “pingo”, derived from its desorption. In addition to traditional production, some producers in the Serro region use “rala” as endogenous starter, obtained by grating the MAC after 3-5 days of manufacture. The change of endogenous starter can lead to changes in the MAC microbiota, including the lactic microbiota that plays a fundamental role in production, ripening, development of sensory characteristics, bioconservation and safety. Knowledge of the MAC's autochthonous lactic microbiota helps to characterize its identity, allowing its consolidation as a regional symbol. The study of the microbiota of fermented foods is usually carried out by culture-dependent methods, limited by the complex microbiota and by the cultivation of part of the microbiota. As an alternative, culture-independent methods have been increasingly used; these methods also have some limitations, such as difficulty in differentiating between viable and non-viable microorganisms. The ideal approach to characterize the microbiota of artisanal cheeses is the association of culture-dependent and -independent methods. This study aimed to characterize the autochthonous lactic microbiota of the QMA do Serro with different production characteristics by culture-dependent and culture-independent methods. Samples of MAC do Serro (n = 55) were obtained from the Cooperativa de Produtores Rurais do Serro (CooperSerro) and characterized for endogenous starter (“pingo” and “rala”), producer city (Alvorada de Minas, Sabinópolis, Santo Antônio do Imbé, Serra Azul de Minas and Serro), farm size (daily milk production) and time of production (days). The samples were subjected to enumeration of lactic acid bacteria (LAB) in MRS Agar, pH 5.7 and obtaining isolates (n = 176) that were characterized by Repetitive extragenic palindromic-PCR (Rep-PCR) and identified by region sequencing V1-V3 of the 16S rRNA. In parallel, the samples were submitted to total DNA extraction for characterization of microbial diversity by Rep-PCR, Denaturing Gradient Gel Eletrophoresis (DGGE) and sequencing of the V3-V4 region of the 16S rRNA. LAB counts in samples and MAC of Serro ranged between 5.4 and 8.4 log CFU/g with a mean value of 6.9 log CFU/g, and the main groups/genus identified were lactobacilli, Lactococcus lactis and Enterococcus sp.; trends in LAB counts and distribution were not identified considering the characteristics of the samples. Rep-PCR identified intraspecies similarities greater than 75%. The sequencing of DGGE bands identified the prevalence of L. lactis in all samples, in addition to Streptococcus salivarius. Considering the total DNA of the samples, L. lactis was identified as the dominant species in all samples. Rep-PCR and DGGE have proven to be useful tools for studying the lactic microbiota of artisanal cheeses. The integrated approach of the culture- dependent and -independent methods provided a more detailed description of the lactic diversity present in the MAC of Serro. The lactic microbiota of MAC of Serro has a stable composition, with no evident variations considering the evaluated production characteristics. Keywords: Lactic acid bacteria. Pingo. Rala. Culture-dependent. Culture-independent. Sequencing.
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- 2021
33. Estudo de estratégia de contenção do crescimento de micro-organismos patogênicos em alimentos
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Delboni, Roberta Regina, 1979, Yang, Hyun Mo, 1959, Calsavara, Bianca Morelli Rodolfo, Boldrini, José Luiz, Fontanari, José Fernando, Mancera, Paulo Fernando de Arruda, Universidade Estadual de Campinas. Instituto de Matemática, Estatística e Computação Científica, Programa de Pós-Graduação em Matemática Aplicada, and UNIVERSIDADE ESTADUAL DE CAMPINAS
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Nonlinear partial differential equations ,Traveling waves ,Bacteriocins ,Equações diferenciais ordinárias ,Equações diferenciais parciais não-lineares ,Ondas viajantes ,Bacteriocinas ,Ordinary differential equations - Abstract
Orientador: Hyun Mo Yang Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Matemática Estatística e Computação Científica Resumo: A contaminação microbiana é um grande problema para a indústria de alimentos e também para a saúde pública. As perdas econômicas ocorrem devido aos processos civis que representam um impacto negativo para a indústria. O desafio é o atendimento de demandas por alimentos minimamente processados, que não foram submetidos a tratamentos térmicos intensos, para reduzir a adição de conservadores químicos, mas ao mesmo tempo, garantir a segurança microbiológica desses produtos. Bactérias lácticas são tradicionalmente utilizadas na produção de alimentos fermentados. Elas são responsáveis pela produção de compostos antimicrobianos, tais como ácidos orgânicos e bacteriocinas, que são compostos protéicos que possuem efeito bactericida contra espécies relacionadas e outras bactérias, tais como Listeria monocytogenes e Staphylococcus aureus. Para estudar quantitativamente o controle biológico como técnica de conservação, desenvolvemos um modelo matemático para descrever a interação entre bactérias lácticas e bactérias contaminantes em alimentos. O diferencial do modelo proposto é a inclusão do efeito de quorum sensing na taxa de crescimento das bactérias lácticas e também na taxa de produção da bacteriocina. O objetivo desse estudo é encontrar os limiares que determinam a existência de múltiplos equilíbrios e analisar a sua importância biológica. A análise dos estados estacionários e das trajetórias dinâmicas do modelo permite-nos estudar a possível utilização de bactérias lácticas com a finalidade de reduzir o crescimento de bactérias indesejáveis nos alimentos Abstract: Microbial contamination is a big problem for the food industry and also for the public health. The economic losses occur due to civil process impacting negatively to the industry. The challenge is the attending demands for minimally processed foods, such as the avoiding of intense heat treatments and the reduction of the addition of chemical preservatives, but at the same time ensuring microbiological safety of these products. Lactic acid bacteria are traditionally used in the production of fermented foods. They are responsible for the production of antimicrobial compounds, such as organic acids and bacteriocins, which are protein compounds with bactericidal effect against related species and bacteria such as Listeria monocytogenes and Staphylococcus aureus. Aiming to study quantitatively the biological control as a technique of conservation, we developed a mathematical model to describe the interaction between lactic acid bacteria and contaminating bacteria in the food. The differential of the proposed model is the inclusion of quorum sensing effect in the growth rate of lactic acid bacteria and also in the bacteriocin production rate. The goal of this study is to find the thresholds which determine the existence of multiple equilibria and analyze their biological significance. The steady state and dynamical trajectories analyses of the model permit us to study the suitability of including lactic bacteria in order to reduce the growth of undesirable bacteria in food Doutorado Matemática Aplicada Doutora em Matemática Aplicada FAPESP 2008/10735-0 CAPES 10172/12-2
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- 2021
34. Analise da frequencia e da expressão de genes de biossintese de mutacinas em isolados de Streptococcus mutans
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Kamiya, Regianne Umeko, Gonçalves, Reginaldo Bruno, 1966, Jorge, Antonio Olavo Cardoso, Ito, Izabel Yoko, Rosalen, Pedro Luiz, Höfling, José Francisco, Universidade Estadual de Campinas. Faculdade de Odontologia de Piracicaba, Programa de Pós-Graduação em Biologia Buco-Dental, and UNIVERSIDADE ESTADUAL DE CAMPINAS
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Streptococcus mutans ,Antibacterial agents ,Fatores de virulência ,Virulence factors ,Bacteriocins ,Gene expression ,Expressão gênica ,Agentes antibacterianos ,Bacteriocinas - Abstract
Orientador: Reginaldo Bruno Gonçalves Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba Resumo: Esta tese, apresentada na forma de 3 artigos, teve por objetivos: (1) analisar a freqüência dos genes de produção de mutacinas I, II, III e IV, em genótipos de S. mutans isolados de indivíduos cárie-ativos e livres de cárie, (2) analisar a freqüência dos genes de produção das mutacinas I, II, III, IV, N, B-Ny 266, 1140 e genes homólogos às bacteriocinas, identificadas em outras espécies bacterianas, em cepas de S. mutans isolados de crianças, bem como detectar a expressão diferencial dos genes identificados, em células de S. mutans crescidas na condição planctônica e séssil, (3) analisar a expressão dos genes de produção das mutacinas I, II e proteínas kinases CiaH, Dgk e ComD, em diferentes fases do crescimento planctônico e séssil. O rastreamento e a freqüência dos genes estruturais de diferentes mutacinas em isolados de S. mutans, foram realizados pela técnica de PCR e a análise da expressão gênica, pela técnica de RT-PCR semi-quantitativa. Os estudos, apresentados nesta tese, demonstraram o papel das mutacinas como um fator de virulência, altamente diversificado entre a espécie S. mutans, e relacionado com o risco de cárie. Este fator de virulência, pode ser regulado por mecanismos quorum-sensing, sendo assim, dependente da condição de crescimento planctônica ou séssil. A regulação da produção de mutacinas, por mecanismos quorum-sensing, pode representar uma vantagem seletiva à espécie produtora, principalmente em ambiente complexo, como o biofilme dental e lesões de cárie. Futuramente, mais estudos serão necessários para identificar novos determinantes genéticos, necessários para a síntese de substâncias semelhantes às mutacinas, bem como, identificar os mecanismos e componentes, que modulam a expressão deste importante fatorde virulência em S. mutans Abstract: This thesis, comprised of 3 manuscripts was designed (1) to analyse the frequency of biosynthesis genes of the mutacins types I, II, III and IV, in S. mutans isolated from caries-affected and caries-free individuals, (2) to analyse the frequency of biosynthesis genes of the mutacins types I, II, III, IV, N, B-Ny 266, 1140 and genes homologues to bacteriocins identified in other bacterial species, in S. mutans isolated from children, in addition, to detect the differential expression of these genes, in S. mutans cells grown in planktonic and sessil conditions, (3) and to analyse the expression of the mutacins I and II production genes and kinase proteins genes (ciaH, dgk e comD), in different phases of the planktonic and sessile growth. The screening and frequency of the mutacins structural genes in S. mutans isolates were realized by PCR technique and the analysis of genetic expression, by RT-PCR semiquantitative method. The studies, presented in this thesis, demonstrate the role of mutacins as a virulence factor, highly diverse among S. mutans, and related to risk of dental caries. The mutacins production may be regulated by quorum-sensing mechanisms and is dependent on planktonic and sessile conditions. The modulation by quorum-sensing mechanisms may represent a selective advantage for producer S. mutans strain, mainly in complex environments as the dental biofilm and caries. Hereafter, more studies will be necessary to identify new genetic determinants for synthesis of mutacin-like substances and elucidate the mechanisms and components that modulate the genetic expression of this important virulence factor in S. mutans Doutorado Microbiologia e Imunologia Doutor em Biologia Buco-Dental
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- 2021
35. El género Weissella en la industria alimentaria: Una revisión
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Teixeira, Camila Gonçalves, Silva, Raiane Rodrigues da, Fusieger, Andressa, Martins, Evandro, Freitas, Rosângela de, and Carvalho, Antônio Fernandes de
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Metabolismo ,Metabolism ,Potencial tecnológico ,Food industry ,Ecology ,Weissella ,Industria de alimentos ,Bacteriocinas ,Bacteriocins ,Ecología ,Technological potential ,Indústria alimentícia ,Ecologia - Abstract
The genus Weissella is composed of bacteria classified as Gram-positive, catalase negative, non-spore forming, coccoid morphology or short bacilli. They belong to the group of lactic acid bacteria (LAB), mainly by production of lactic acid from the fermentation of carbohydrates. Weissella species are distributed in different habitats, such as soils, milking machines, sugar cane and some strains with interesting technological features can be isolated from fermented foods, such as cheeses made from raw milk, fermented vegetables and fermented milk. From the point of view of food technology, some strains have potential in the production of exopolysaccharides, non-digestible oligosaccharides, which is beyond their probiotic potential. Therefore, the bacteria belonging to the genus Weissella might have great technological importance, being also involved in the control of foodborne diseases by production of bacteriocins and hydrogen peroxide. This genus has great potential for use in the food industry. El género Weissella está compuesto por bacterias clasificadas como gram-positivas, catalasa negativas, no formadoras de esporas, de morfología cocoide o bacilos cortos. Pertenecen al grupo de las bacterias del ácido láctico (BAL), principalmente por la producción de ácido láctico a partir de la fermentación de carbohidratos. Las especies de Weissella se encuentran distribuidas en distintos hábitats, como suelos, ordeñadoras, caña de azúcar y algunas cepas con interesantes características tecnológicas pueden aislarse de alimentos fermentados, como quesos elaborados a partir de leche cruda, vegetales fermentados y leche fermentada. Desde el punto de vista de la tecnología de los alimentos, algunas cepas tienen potencial en la producción de exopolisacáridos, oligosacáridos no digeribles, que está más allá de su potencial probiótico. Por tanto, las bacterias pertenecientes al género Weissella podrían tener una gran importancia tecnológica, estando también implicadas en el control de enfermedades transmitidas por alimentos mediante la producción de bacteriocinas y peróxido de hidrógeno. Este género tiene un gran potencial para su uso en la industria alimentaria. O gênero Weissella é composto por bactérias classificadas como Gram-positivas, catalase negativas, não formadoras de esporos, morfologia cocóide ou bacilos curtos. Pertencem ao grupo das bactérias lácticas (BAL), principalmente pela produção de ácido láctico a partir da fermentação de carboidratos. As espécies de Weissella estão distribuídas em diferentes habitats, como solos, ordenhadeiras, cana-de-açúcar e algumas cepas com características tecnológicas interessantes podem ser isoladas de alimentos fermentados, como queijos de leite cru, vegetais fermentados e leite fermentado. Do ponto de vista da tecnologia de alimentos, algumas cepas apresentam potencial na produção de exopolissacarídeos, oligossacarídeos não digeríveis, que está além de seu potencial probiótico. Portanto, as bactérias pertencentes ao gênero Weissella podem ter grande importância tecnológica, estando também envolvidas no controle de doenças de origem alimentar pela produção de bacteriocinas e peróxido de hidrogênio. Este gênero possui grande potencial para uso na indústria alimentícia.
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- 2021
36. Antagonistic action of Lactobacillus spp. against Staphylococcus aureus in cheese from Mompox – Colombia.
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Montero Castillo, Piedad M., Díaz Caballero, Antonio, and Durán Lengua, Marlene
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ANTIBIOSIS , *BACTERIOCINS , *COMPOSITION of dairy products , *LACTOBACILLUS , *STAPHYLOCOCCUS aureus - Abstract
In the food industry, food preservation techniques that do not use chemical products are becoming more common. Therefore, the aim of this research was to evaluate the antagonistic activity (antibiosis) of lactic-acid bacterial strains against pathogenic microorganisms. Lactic-acid bacterial strains were isolated from layered cheese and a commercial product (yogurt); and the same was done with pathogenic bacteria solely from layered cheese. The lactic-acid bacterial strains were identified as species from the Lactobacilli family, while the pathogenic bacteria from layered cheese were identified as Micrococcaceae family species (Staphylococcus aureus). Subsequently, in the same culture medium, bacteria of each species were sowed in order to determine the inhibitory activity ability of the Lactic Acid Bacteria (BAL) As a result, the highly antagonistic activity of the Lactobacilli (inhibition halos were larger than 0.5 centimeters in diameter) against isolated pathogenic microorganisms was demonstrated. [ABSTRACT FROM AUTHOR]
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- 2015
- Full Text
- View/download PDF
37. The importance of antimicrobial compounds produced by beneficial bacteria on the biocontrol of phytopathogens
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Cesa-Luna, Catherine, Baez, Antonino, Quintero-Hernández, Verónica, De la Cruz-Enríquez, Joel, Castañeda-Antonio, Ma Dolores, Muñoz-Rojas, Jesús, Cesa-Luna, Catherine, Baez, Antonino, Quintero-Hernández, Verónica, De la Cruz-Enríquez, Joel, Castañeda-Antonio, Ma Dolores, and Muñoz-Rojas, Jesús
- Abstract
Bacteria produce antimicrobial compounds to compete for nutrients and space in a particular habitat. Antagonistic interactions can be evaluated by several methodologies including the double-layer agar and simultaneous inhibition assays. Among the well-known inhibitory substances produced by bacteria are the broad-spectrum antibiotics, organic acids, siderophores, antifungal, and bacteriocins. The most studied bacterial genera able to produce these inhibitory substances are Enterococcus, Lactococcus, Streptomyces, Bacillus, Pseudomonas, Klebsiella, Escherichia, and Burkholderia. Some beneficial bacteria can promote plant growth and degrade toxic compounds in the environment representing an attractive solution to diverse issues in agriculture and soil pollution, particularly in fields with damaged soils where pesticides and fertilizers have been indiscriminately used. Beneficial bacteria may increase plant health by inhibiting pathogenic microorganisms; some examples include Gluconacetobacter diazotrophicus, Azospirullum brasilense, Pseudomonas fluorescens, Pseudomonas protegens, and Burkholderia tropica. However, most studies showing the antagonistic potential of these bacteria have been performed in vitro, and just a few of them have been evaluated in association with plants. Several inhibitory substances involved in pathogen antagonism have not been elucidated yet; in fact, we know only 1 % of the bacterial diversity in a natural environment leading us to assume that many other inhibitory substances remain unexplored. In this review, we will describe the characteristics of some antimicrobial compounds produced by beneficial bacteria, the principal methodologies performed to evaluate their production, modes of action, and their importance for biotechnological purposes., Las bacterias producen compuestos antimicrobianos para competir por nutrientes y espacio en un hábitat particular. Las interacciones antagónicas pueden evaluarse mediante varias metodologías, incluido el agar de doble capa y los ensayos de inhibición simultánea. Las sustancias inhibidoras mejor conocidas producidas por bacterias incluyen antibióticos, ácidos orgánicos, sideróforos, antifúngicos y bacteriocinas. Entre los géneros bacterianos más estudiados que producen sustancias inhibidoras se incluyen Enterococcus, Lactococcus, Streptomyces, Bacillus, Pseudomonas, Klebsiella, Escherichia y Burkholderia. Algunas bacterias beneficiosas tienen la capacidad de promover el crecimiento de las plantas y degradar compuestos tóxicos en el ambiente, por lo que podrían incrementar el rendimiento de los cultivos y disminuir problemas de contaminación del suelo, especialmente donde los pesticidas y fertilizantes han sido utilizados indiscriminadamente. Algunas bacterias beneficiosas pueden aumentar la salud de las plantas al inhibir microorganismos patógenos, por ejemplo, Gluconacetobacter diazotrophicus, Azospirullum brasilense, Pseudomonas fluorescens, Pseudomonas protegens y Burkholderia tropica. Sin embargo, la mayoría de los estudios que muestran el potencial antagónico de estas bacterias se han realizado in vitro, y pocos de ellos se han evaluado en asociación con plantas. Varias sustancias inhibitorias implicadas en el antagonismo de los patógenos aún son desconocidas; de hecho, sabemos que solo se ha aislado el 1 % de la diversidad bacteriana en un ambiente natural, lo que sugiere que hay muchas otras sustancias inhibitorias que no han sido exploradas. En esta revisión describimos las características de algunos compuestos antimicrobianos producidos por bacterias beneficiosas, las principales metodologías usadas para evaluar su producción, modos de acción y su importancia para fines biotecnológicos.
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- 2020
38. Functional potential of Leuconostoc mesenteroides LB10.4 and Lactococcus lactis L4A8 buffala milk isolates
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Badillo Almeira, Carlos Augusto and Motta, Amanda de Souza da
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Lactococcus lactis ,Alimento funcional ,Probióticos ,Leuconostoc mesenteroides ,Bacteriocinas ,Leite de búfala - Abstract
O crescente interesse por alimentos funcionais faz com que a indústria procure novas linhagens de bactérias com potencial funcional. Neste contexto, o leite de búfala pode ser utilizado para o isolamento de cepas BALs com eventual potencial probiótico ou tecnológico. O objetivo deste trabalho foi explorar o potencial funcional de Leuconostoc mesenteroides LB10.4 e Lactococcus lactis L4A8 isolados do leite de búfala e identificar aplicações na indústria de alimentos. Para atingir este objetivo, foram avaliados testes de inocuidade, atividade antimicrobiana, propriedades tecnológicas, condições de temperatura, influência de conservantes alimentares, tolerância em condições do trato gastrointestinal, avaliação da eficiência de microencapsulação e manutenção das culturas microencapsuladas aplicada em leite UHT e em caldo MRS. Os resultados da inocuidade não apresentaram atividade hemolítica nem produção de gelatinase. Leuconostoc mesenteroides LB10.4 apresentou resultado mais tardio da atividade proteolítica-acidificante em Litmus Milk em comparação à Lactococcus lactis L4A8. Em ágar leite, ambas apresentaram atividade proteolítica. Não foi detectada atividade lipolítica, produção de gás e hidrólise da lisina. Os isolados demostraram ser capazes de obter crescimento microbiano em temperaturas de 20, 30 e 37ºC. Também, sofreram efeitos moderados das bacteriocinas Nisina e Pediocina. Em associação, os isolados apresentaram tolerância adversa ao trato gastrointestinal e viabilidade na liberação das células microencapsuladas aplicadas em Leite UHT. Os resultados mostraram-se promissores à aplicação na indústria alimentícia como culturas starter. The growing interest in functional foods makes the industry look for new strains of bacteria with functional potential. In this context, buffalo milk can be used for isolating BALs strains with probiotic or technological potential. This work objective was to explore the functional potential of Leuconostoc mesenteroides LB10.4 and Lactococcus lactis L4A8 isolated from buffalo milk and to identify their applications in food industry. To achieve this objective, safety tests, antimicrobial activity, technological properties, temperature conditions, influence of food preservatives, tolerance in conditions of the gastrointestinal tract, evaluation of microencapsulation efficiency and maintenance of microencapsulated cultures applied in UHT milk and broth MRS were all evaluated. Innocuity results did not show hemolytic activity or gelatinase production. Leuconostoc mesenteroides LB10.4 showed a later result of proteolytic-acidifying activity in Litmus Milk compared to Lactococcus lactis L4A8. In milk agar, both showed proteolytic activity. No lipolytic activity, gas production and lysine hydrolysis were detected. The isolates demonstrated microbial growth at temperatures of 20, 30 and 37ºC. Also, they suffered moderate effects from the bacteriocins Nisina and Pediocina. In association, the isolates showed tolerance to the gastrointestinal tract and viability in the release of microencapsulated cells applied in UHT milk. The results showed promise for application in the food industry as starter crops.
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- 2021
39. Listeriolysin S : a bacteriocin from 'Listeria monocytogenes' that induces membrane permeabilization in a contact-dependent manner
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Meza Torres, Jazmín., Lelek, Mickaël., Quereda Torres, Juan José., Sachse, Martin., Manina, Giulia., Ershov, Dmitry., UCH. Departamento de Producción y Sanidad Animal, Salud Pública Veterinaria y Ciencia y Tecnología de los Alimentos, and Producción Científica UCH 2021
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Listeriosis ,Intoxicación por alimentos ,Bacteriocinas ,Veterinary microbiology ,Listeriolysin S (LLS) ,Microbiología veterinaria ,Listeria monocytogenes ,Bacteriocins ,Food poisoning - Abstract
Este artículo se encuentra disponible en la siguiente URL: https://www.pnas.org/doi/epdf/10.1073/pnas.2108155118 En este artículo de investigación también participan: Jean-Yves Tinevez, Lilliana Radoshevich, Claire Maudet, Thibault Chaze, Quentin Giai Gianetto, Mariette Matondo, Marc Lecuit, Isabelle Martin-Verstraete, Christophe Zimmer, Hélène Bierne, Olivier Dussurget, Pascale Cossart y Javier Pizarro-Cerdá. Listeriolysin S (LLS) is a thiazole/oxazole–modified microcin (TOMM) produced by hypervirulent clones of Listeria monocytogenes. LLS targets specific gram-positive bacteria and modulates the host intestinal microbiota composition. To characterize the mechanism of LLS transfer to target bacteria and its bactericidal function, we first investigated its subcellular distribution in LLS-producer bacteria. Using subcellular fractionation assays, transmission electron microscopy, and single-molecule superresolution microscopy,we identified that LLS remains associated with the bacterial cell membrane and cytoplasm and is not secreted to the bacterial extracellular space. Only living LLS-producer bacteria (and not purified LLS-positive bacterial membranes) display bactericidal activity. Applying transwell coculture systems and microfluidic-coupled microscopy, we determined that LLS requires direct contact between LLS-producer and -target bacteria in order to display bactericidal activity, and thus behaves as a contact-dependent bacteriocin. Contact-dependent exposure to LLS leads to permeabilization/depolarization of the target bacterial cell membrane and adenosine triphosphate (ATP) release. Additionally, we show that lipoteichoic acids (LTAs) can interact with LLS and that LTA decorations influence bacterial susceptibility to LLS. Overall, our results suggest that LLS is a TOMM that displays a contact-dependent inhibition mechanism.
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- 2021
40. Genome mining for antimicrobial compounds in wild marine animals-associated Enterococci
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Prichula, Janira, Barros, Muriel Primon de, Luz, Romeu C. Z., Castro, Ícaro Maia Santos de, Paim, Thiago Galvão da Silva, Tavares, Maurício, D'Azevedo, Pedro Alves, Frazzon, Jeverson, Frazzon, Ana Paula Guedes, Seixas, Adriana, and Gilmore, Michael S.
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Genoma microbiano ,Anti-infecciosos ,Bacteriocins ,Wild marine species ,Enterococci ,Genome-wide analysis ,Probiotics ,Família multigênica ,Enterococcus ,Bacteriocinas ,Fauna marinha - Abstract
New ecosystems are being actively mined for new bioactive compounds. Because of the large amount of unexplored biodiversity, bacteria from marine environments are especially promising. Further, host-associated microbes are of special interest because of their low toxicity and compatibility with host health. Here, we identified and characterized biosynthetic gene clusters encoding antimicrobial compounds in host-associated enterococci recovered from fecal samples of wild marine animals remote from human-affected ecosystems. Putative biosynthetic gene clusters in the genomes of 22 Enterococcus strains of marine origin were predicted using antiSMASH5 and Bagel4 bioinformatic software. At least one gene cluster encoding a putative bioactive compound precursor was identified in each genome. Collectively, 73 putative antimicrobial compounds were identified, including 61 bacteriocins (83.56%), 10 terpenes (13.70%), and 2 (2.74%) related to putative nonribosomal peptides (NRPs). Two of the species studied, Enterococcus avium and Enterococcus mundtti, are rare causes of human disease and were found to lack any known pathogenic determinants but yet possessed bacteriocin biosynthetic genes, suggesting possible additional utility as probiotics. Wild marine animal-associated enterococci from human-remote ecosystems provide a potentially rich source for new antimicrobial compounds of therapeutic and industrial value and potential probiotic application.
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- 2021
41. Enterocin Cross-Resistance Mediated by ABC Transport Systems
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M. Esther Fárez-Vidal, Manuel Martínez-Bueno, Mercedes Maqueda, Eva Valdivia, Juan Manuel Peralta-Sánchez, Claudia Teso-Pérez, Antonio M. Martín-Platero, [Teso-Pérez,C, Martínez-Bueno,M, Peralta-Sánchez,JM, Valdivia,E, Maqueda,M, Martín-Platero,AM] Departamento de Microbiología, Universidad de Granada, Granada, Spain. [Fárez-Vidal,ME] Departamento de Bioquímica y Biología Molecular III e Inmunología, Facultad de Medicina, Universidad de Granada, Granada, Spain. [Fárez-Vidal,ME] Instituto de Investigación Biomédica IBS, Granada, Complejo Hospitalario Universitario de Granada, Universidad de Granada, Granada, Spain., and This research was funded by Junta de Andalucía (Programa Operativo FEDER Andalucía 2014–2020), grant number A-BIO-083-UGR18. C.T.-P. was funded by Plan Estatal de Garantía Juvenil (Fondo Social Europeo, Gobierno de España, Ref. PEJ2018-003019-A).
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Microbiology (medical) ,QH301-705.5 ,Enterocin ,Antimicrobial peptides ,Mutant ,ATP-binding cassette transporter ,Microbiology ,Article ,Enterococcus faecalis ,MR10A/B ,03 medical and health sciences ,Chemicals and Drugs::Amino Acids, Peptides, and Proteins::Proteins::Membrane Proteins::Membrane Transport Proteins::ATP-Binding Cassette Transporters [Medical Subject Headings] ,Shuttle vector ,Bacteriocin ,Inmunidad ,Virology ,Gene cluster ,Chemicals and Drugs::Amino Acids, Peptides, and Proteins::Proteins::Bacterial Proteins::Bacteriocins [Medical Subject Headings] ,Biology (General) ,Bacteriocin immunity ,Bacteriocinas ,030304 developmental biology ,bacteriocin immunity ,Genetics ,0303 health sciences ,biology ,030306 microbiology ,Vectores genéticos ,food and beverages ,Phenomena and Processes::Immune System Phenomena::Immunity [Medical Subject Headings] ,biochemical phenomena, metabolism, and nutrition ,biology.organism_classification ,Phenomena and Processes::Genetic Phenomena::Genetic Structures::Genetic Vectors [Medical Subject Headings] ,Transportadoras de casetes de unión a ATP ,enterocin ,Organisms::Bacteria::Gram-Positive Bacteria::Lactobacillales::Enterococcaceae::Enterococcus::Enterococcus faecalis [Medical Subject Headings] ,bacteria ,Chemicals and Drugs::Chemical Actions and Uses::Pharmacologic Actions::Therapeutic Uses::Anti-Infective Agents [Medical Subject Headings] ,ABC transporter ,Phenomena and Processes::Genetic Phenomena::Genetic Structures::Genome::Genome Components::Genes::Multigene Family [Medical Subject Headings] ,AS-48 - Abstract
In their struggle for life, bacteria frequently produce antagonistic substances against competitors. Antimicrobial peptides produced by bacteria (known as bacteriocins) are active against other bacteria, but harmless to their producer due to an associated immunity gene that prevents selfinhibition. However, knowledge of cross-resistance between different types of bacteriocin producer remains very limited. The immune function of certain bacteriocins produced by the Enterococcus genus (known as enterocins) is mediated by an ABC transporter. This is the case for enterocin AS-48, a gene cluster that includes two ABC transporter-like systems (Transporter-1 and 2) and an immunity protein. Transporter-2 in this cluster shows a high similarity to the ABC transporter-like system in MR10A and MR10B enterocin gene clusters. The aim of our study was to determine the possible role of this ABC transporter in cross-resistance between these two different types of enterocin. To this end, we designed different mutants (Tn5 derivative and deletion mutants) of the as-48 gene cluster in Enterococcus faecalis and cloned them into the pAM401 shuttle vector. Antimicrobial activity assays showed that enterocin AS-48 Transporter-2 is responsible for cross-resistance between AS-48 and MR10A/B enterocin producers and allowed identification of the MR10A/B immunity gene system. These findings open the way to the investigation of resistance beyond homologous bacteriocins., Junta de Andalucía (Programa Operativo FEDER Andalucía 2014–2020), grant number A-BIO-083-UGR18, Plan Estatal de Garantía Juvenil (Fondo Social Europeo, Gobierno de España, Ref. PEJ2018-003019-A)
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- 2021
42. Screening and characterization of bacteriocins produced by bacteria against Escherichia coli and Staphylococcus aureus
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Casado García-Consuegra, Zulema
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Bacteriocins ,Antibiotics ,Escherichia coli ,Lactic acid bacteria ,BIOQUIMICA Y BIOLOGIA MOLECULAR ,Grado en Biotecnología-Grau en Biotecnologia ,Purificación ,Antibióticos ,Bacterias ácido-lácticas ,Bacteriocinas ,Purification - Abstract
[ES] En los últimos años, la aparición de bacterias resistentes a los antibióticos se ha convertido en una amenaza mundial debido al mal uso y abuso de estas sustancias en el tratamiento de enfermedades animales y humanas. Por este motivo, tratamientos convencionales para ciertas patologías han perdido total o parcialmente su efectividad. Además, la presencia de antibióticos en el medio ambiente tiene un impacto de larga duración que incrementa la incidencia de resistencias. Con el objetivo de controlar esta crisis emergente, las bacteriocinas se consideran una alternativa plausible ya que son capaces de matar a las bacterias resistentes mediante un mecanismo de acción que difiere del que presentan los antibióticos convencionales. Las bacteriocinas son proteínas biológicamente activas sintetizadas por las bacterias y secretadas al medio extracelular, donde presentan actividad antimicrobiana contra otras bacterias. Concretamente, las bacteriocinas producidas por bacterias ácido-lácticas son especialmente interesantes ya que son reconocidas como seguras (GRAS), y no presentan toxicidad en humanos debido a que son degradadas por proteasas en el tracto intestinal. El objetivo de nuestro estudio es aislar, caracterizar y purificar bacteriocinas ácido-lácticas que puedan inhibir al patógeno Gram negativo de origen alimentario Escherichia coli., [EN] In recent years, bacterial antibiotic resistance has become a worldwide hazard due to the misuse and abuse of antibiotics in the treatment of animal and human disorders. The emergence of resistant bacteria leads some conventional treatments to lose partial or total effectiveness. Moreover, the leaking of antibiotics into the environment has a long-lasting impact which increases the incidence of resistances. To control the resistance crisis, bacteriocins are considered one plausible alternative because may kill antibiotic-resistant bacteria using a different killing mechanism than antibiotics. Bacteriocins are proteins biologically active from bacteria, which are secreted to the extracellular medium, and have an antimicrobial action against other bacteria. Concretely, bacteriocins produced by lactic acid bacteria are specially interesting because they are generally recognized as safe (GRAS), and have no toxicity in humans since they are degraded by proteases in the intestinal tract. The purpose of our study is to isolate, characterize, and purify lactic acid bacteriocins which may inhibit the Gram-negative foodborne pathogen Escherichia coli.
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- 2021
43. Búsqueda, extracción, purificación y elucidación de productos naturales a partir de microorganismos
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Salazar De La Luz, Francisco Fidel, Sansisinenea Royano, Estibaliz, and Ortiz Márquez, J. Aurelio
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Biotecnología ,Agentes antibacteriales ,Bacillus amyloliquefaciens ,BIOLOGÍA Y QUÍMICA ,Lipopéptidos ,Bacteriocinas ,Policétidos - Abstract
“El presente trabajo se desarrolló en el área de Productos Naturales, compuestos orgánicos derivados del metabolismo secundario de organismos vivos. En este proyecto se utilizaron dos microorganismos de interés; la bacteria Bacillus amyloliquefaciens y un hongo endófito Fusarium sp, por lo cual este trabajo se ha dividido en dos capítulos. En el primer capítulo se presenta el estudio de los compuestos orgánicos aislados de la bacteria B. amyloliquefaciens ELI149, con ayuda de la resina adsorbente Amberlita® XAD-16. Los compuestos estudiados son: de tipo bacteriocina con un amplio espectro de actividad antibacteriana, las cuales demostraron una alta resistencia al calor y pH (2-10) conservando su actividad, dos lipopéptidos llamados Surfactina y Fengicina, con actividad antifúngica contra hongos fitopatógenos, y por último se aislaron dos compuestos tipo policétidos (macrolactinas) que con ayuda de la espectroscopia de RMN 1D y RMN 2D se lograron identificar sus estructuras adecuadamente y se probó su actividad frente a hongos fitopatógenos en una concentración mínima (1 mg/mL) lográndose observar el daño celular producido por estos compuestos a microscopia de contraste de fases. En el segundo capítulo se presenta el estudio de los compuestos orgánicos obtenidos de un hongo endófito llamado Fusarium sp. aislado de la planta Mentha rotundifolia para evaluar su potencial biotecnológico.”
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- 2020
44. Identificación y caracterización microbiológica, fenotípica y genotípica del Streptococcus mutans: experiencias de investigación.
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Gamboa Jaimes, Fredy Omar
- Abstract
Background: Dental caries is a localized, transmissible, infectious, and pathological process that leads to the destruction of the dental hard tissue. In ecological terms, this disease is caused by an imbalance in the oral ecosystem leading to the dominance of a flora, previously considered normal in the mouth and now treated as pathogenic. The main microorganisms associated to cariogenesis are, in order of frequency: (1) Streptococcus mutans (S. mutans) (mainly serotype c) and to a lesser extent S. sobrinus and S. gordonii; and (2) species of Lactobacillus and Actinomyces. Overall, the scientific community's consensus identifies S. mutans as the most important microorganism in dental caries. Therefore, isolation, identification, characterization, prevention and control strategies are directed primarily against S. mutans. Method: Based on our own research experience and contrasting it with that of other research groups this article describes the microbiology, isolation strategies, counting, and identification of S. mutans from dental plaque and saliva samples. It also depicts aspects of phenotyping, genotyping, phenotypic detection of bacteriocins and antimicrobial susceptibility of S. mutans strains. Conclusion: The correct understanding of the phenotypic and genotypic characteristics of S. mutans should lead to designing better prevention and control strategies. [ABSTRACT FROM AUTHOR]
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- 2014
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45. EFECTO DE FACTORES EXTRINSECOS SOBRE LA ACTIVIDAD ANTIMICROBIANA DEL METABOLITO W10b PRODUCIDO POR (Weissella confusa).
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SERNA-COCK, LILIANA, LEIDY JOHANA VALENCIA, H., and ANGELA VIVIANA RUALES, S.
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Antimicrobial substances produced by lactic acid bacteria (LAB) may lose activity due to extrinsic factors. This study determined the effects of temperature, pH, and exposure to enzymes, on the activity of antimicrobial compounds (W10b) isolated from Weissella confusa. W10b were active against Staphylococcus aureus and Streptococcus agalactiae. W. confusa was obtained by fermentation at 32°C for 4 h and W10b by centrifugation, microfiltration, and lyophilization from the resulting cell-free supernatant W10b was exposed to acidic, neutral and basic pH, for two residence times (10 and 30 minutes) and four temperatures (27, 40, 60, and 100°C). The effect of the enzymes pepsin and amyloglucosidase on W10b was also determined. Significant differences (P< 0,05) on the antimicrobial activity of W10b due to pH and temperature were found. The highest antimicrobial activity was obtained against S. aureus at basic pH and 27°C, and against S. agalactiae at neutral pH and 27°C. W10b presented sensitivity to the pepsin and amyloglucosidase enzymes, indicating the proteinaceous nature and chemical complexity of the compounds. Although further research is needed, antimicrobial compounds from W. confusa have a strong potential to be used in industrial setups. [ABSTRACT FROM AUTHOR]
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- 2014
46. Enterocin microencapsulation in whey aiming the application against food pathogens
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Ramalho, Regiane, Leimann, Fernanda Vitória, Furlaneto-Maia, Luciana, Marques, Leila Larisa Medeiros, and Herrig, Suelen Pereira Ruiz
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Bactérias patogênicas ,Salmonella typhimurium ,Bacteriocins ,CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::TECNOLOGIA DE ALIMENTOS [CNPQ] ,Tecnologia de Alimentos ,Bacteria, Pathogenic ,Bacteriocinas - Abstract
Enterocinas são peptídeos antimicrobianos produzidos pelo gênero Enterococcus, e apresentam grande espectro de inibição contra bactérias potencialmente patogênicas, incluindo as veiculadas por alimentos. Entretanto, a inter-relação entre enterocina e matriz alimentar pode interferir na ação bactericida do peptídeo, assim, a microencapsulação tem sido uma alternativa para este propósito. Diante do exposto, o objetivo desse trabalho foi microencapsular a enterocina produzida por Enterococcus durans MF5 usando soro de leite como agente encapsulante. Para a microencapsulação, soro de leite foi preparado na concentração de 10% acrescido de 10%p/p (E10) e 50%p/p (E50) de enterocina liofilizada. O material foi submetido ao processo de spray drying e foram realizados ensaios para determinar a atividade antimicrobiana do material encapsulado contra as bactérias Salmonella Typhimurium, Escherichia coli, Pseudomonas sp, Staphylococcus aureus, Listeria monocytogenes, Listeria innocua e Listeria ivanovi. O rendimento da microencapsulação foi de 31,66% e 34,16% para as concentrações E10 e E50, respectivamente. Não houve diferença significativa entre a ação antagônica das concentrações E10 e E50, sendo que a enterocina encapsulada apresentou-se eficiente por até 12 horas de cocultivo com células de Listeria sp. Enterocina encapsulada apresentou valores de 6.000 UA.mL-1, sendo superior aos valores de enterocina pura. O dano causado na parede celular das bactérias alvo foi analisado pela Microscopia Eletrônica de Varredura (MEV). A caracterização das partículas obtidas realizou-se por meio das análises de Espectroscopia no Infravermelho com Transformada de Fourier (FTIR) e Calorimetria Diferencial de Varredura (DSC). Os resultados de FTIR mostraram a interação entre enterocina e soro de leite pela redução da intensidade da banda correspondente à estrutura β-pregueada da proteína do soro, que a encapsulação levou a uma modificação da estrutura proteica. Na análise térmica foi observada maior estabilidade térmica da enterocina encapsulada. Em conclusão constatou-se que a microencapsulação de enterocina teve um rendimento satisfatório, e que a encapsulação potencializa o seu poder antimicrobiano, sendo assim a microencapsulação da enterocina é uma técnica totalmente aplicável em industrias. Enterocins are antimicrobial peptides produced by the genus Enterococcus and have a wide spectrum of inhibition against potentially pathogenic bacteria, including those carried by food. However, the interrelationship between enterocin and the food matrix can interfere with the bactericidal action of the peptide. Thus, microencapsulation has been an alternative for this purpose. Given the above, the objective of this work was to microencapsulate the enterocin produced by Enterococcus durans MF5 using whey as an encapsulating agent. For the microencapsulation, whey was prepared at a concentration of 10% with the addition of 10%wt/wt and 50%wt/wt of lyophilized enterocin. The material was subjected to the spray drying process, and tests were performed to determine the antimicrobial activity of the encapsulated material against the bacteria Salmonella Typhimurium, Escherichia coli, Pseudomonas sp, Staphylococcus aureus, Listeria monocytogenes, Listeria innocua, and Listeria ivanovi. The microencapsulation yield was 31.66% and 34.16% for enterocin concentrations of E10 and E50, respectively. There was no significant difference between the antagonistic action of the enterocin concentrations E10 and E50, and the encapsulated enterocin was efficient for up to 12 hours of co-culture with Listeria sp cells. It is also noteworthy that the encapsulated enterocin showed values of 6,000 UA.mL-1, being higher than the values of pure enterocin. The damage caused to the cell wall of the target bacteria was analyzed by Scanning Electron Microscopy (SEM). The characterization of the particles obtained was carried out employing Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC). The FTIR results showed the interaction between enterocin and whey by reducing the intensity of the band corresponding to the β-pleated structure of whey protein, which encapsulation led to a modification of the protein structure. In the thermal analysis, greater thermal stability of the encapsulated enterocin was observed. In conclusion, it was found that enterocin microencapsulation had a satisfactory yield, and that encapsulation potentiates its antimicrobial power, thus enterocin microencapsulation is a fully applicable technique.
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- 2020
47. Bioconservación de alimentos utilizando antimicrobianos de bacterias ácido lácticas
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Raíssa Vieira da Silva, Luciane Maria Colla, Lariane Strack, Christian Oliveira Reinehr, Kátia Bitencourt Sartor, and Rodrigo Cavalheiro Carli
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0301 basic medicine ,Preservative ,Microorganism ,030106 microbiology ,Shelf life ,lcsh:Social Sciences ,03 medical and health sciences ,0404 agricultural biotechnology ,Bacteriocin ,Bacteriocins ,Bioproducts ,lcsh:Science (General) ,Bacteriocinas ,General Environmental Science ,lcsh:LC8-6691 ,Probióticos ,lcsh:Special aspects of education ,business.industry ,Conservação ,Food preservation ,food and beverages ,Probiotics ,04 agricultural and veterinary sciences ,Biopreservation ,Antimicrobial ,040401 food science ,Preservation ,Biotechnology ,lcsh:H ,Conservación ,General Earth and Planetary Sciences ,Business ,lcsh:Q1-390 - Abstract
There is a growing consumer demand for natural foods, and it is of great interest to develop and produce natural and effective substances for food preservation, replacing synthetic preservatives. The growth of bacteria can occur in food due to environmental conditions during handling and storage, even if good manufacturing practices have been observed. This can cause losses for the industry, also becoming a risk of contamination to the consumer, being necessary to develop new techniques for controlling these sources of contamination. Lactic acid bacteria are known for their benefits to the organisms of those who consume them and for the ability to produce, under appropriate conditions, natural antimicrobial compounds, which can be used as biopreservatives in food and contribute to the increase of shelf life. Bacteriocins are proteins or peptides produced in ribosomes that have the capacity to act against certain pathogens, preventing their multiplication in products during the periods of storage and distribution. The aim of this review is to present the main bacteriocin-producing microorganisms, the forms of production, as well as the techniques by which these bioproducts have been applied in the biopreservation of food products and the results obtained. Biopreservation using bacteriocins has been studied and established as a new and important method, however it is necessary to search for production processes of these bacteriocins on a larger scale and with cost reduction, so that their potential can be increasingly explored by science and industry. Studies related to mechanisms of action and applications in food are also necessary in order to support the decisions of regulatory agencies. Existe una creciente demanda de los consumidores de alimentos naturales, y es de gran interés desarrollar y producir sustancias naturales y efectivas para la conservación de alimentos, que reemplacen a los conservantes sintéticos. El crecimiento de bacterias puede ocurrir en los alimentos debido a las condiciones ambientales durante la manipulación y el almacenamiento, incluso si se han observado buenas prácticas de fabricación. Esto puede causar pérdidas para la industria, y también convertirse en un riesgo de contaminación para el consumidor, con la necesidad de desarrollar nuevas técnicas para controlar estas fuentes de contaminación. Las bacterias del ácido láctico son conocidas por sus beneficios para los organismos de quienes las consumen y por su capacidad para producir, en condiciones apropiadas, compuestos antimicrobianos naturales, que pueden usarse como bioconservadores en los alimentos y contribuyen al aumento de la vida útil de los productos. Las bacteriocinas son proteínas o péptidos producidos en los ribosomas que tienen la capacidad de actuar contra ciertos patógenos, evitando su multiplicación en productos durante los períodos de almacenamiento y distribución. El propósito de esta revisión es presentar los principales microorganismos productores de bacteriocinas, las formas de producción, así como las técnicas por las cuales estos bioproductos se han aplicado en la bioconservación de productos alimenticios y los resultados obtenidos. La biopreservación con bacteriocinas se ha estudiado y establecido como un método nuevo e importante, sin embargo, es necesario buscar procesos de producción de estas bacteriocinas a mayor escala y con reducción de costos, de modo que su potencial pueda ser explorado cada vez más por la ciencia y la industria. Los estudios relacionados con los mecanismos de acción y las aplicaciones en los alimentos también son necesarios para apoyar las decisiones de las agencias reguladoras. Há uma crescente demanda dos consumidores por alimentos naturais, sendo de grande interesse desenvolver e produzir substâncias naturais e eficazes para a conservação de alimentos, que substituam os conservantes sintéticos. O crescimento de bactérias pode ocorrer nos alimentos devido às condições ambientais durante o manuseio e armazenamento, mesmo que tenham sido observadas as boas práticas de fabricação. Isto pode ocasionar perdas para a indústria, tornando-se também um risco de contaminação ao consumidor, havendo a necessidade de desenvolver novas técnicas de controle dessas fontes de contaminação. As bactérias ácido-láticas são conhecidas por seus benefícios aos organismos de quem os consome e pela capacidade de produzir, em condições adequadas, compostos antimicrobianos naturais, os quais podem ser utilizados como bioconservadores nos alimentos e contribuir para o aumento da sua vida de prateleira. As bacteriocinas são proteínas ou peptídios produzidos nos ribossomos que possuem capacidade de agir contra determinados patógenos, evitando sua multiplicação nos produtos durante os períodos de armazenamento e distribuição. O objetivo desta revisão é apresentar os principais microrganismos produtores de bacteriocinas, as formas de produção, bem como as técnicas pelas quais esses bioprodutos têm sido aplicados na biopreservação de produtos alimentícios e os resultados obtidos. A biopreservação por bacteriocinas vem sendo estudada e estabelecida como um novo e importante método, entretanto é necessária a busca por processos de produção dessas bacteriocinas em maior escala e com redução do custo, para que cada vez mais seu potencial possa ser explorado pela ciência e pela indústria. Estudos relacionados aos mecanismos de ação e às aplicações em alimentos são também necessários, a fim de subsidiar as decisões das agências reguladoras.
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- 2020
48. Biodiversidad, producción de bacteriocinas, seguridad y propiedades funcionales de cepas bacterianas aisladas de leche materna
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MARÍN GÓMEZ, WENDY MARÍA, LUCAS LÓPEZ, MARÍA DEL ROSARIO, GRANDE BURGOS, MARÍA JOSÉ, GÁLVEZ DEL POSTIGO RUIZ, ANTONIO MIGUEL, and Universidad de Jaén. Departamento de Ciencias de la Salud
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Probioticos ,Biodiversidad Bacteriana ,Leche Humana ,Bacteriocinas - Abstract
Se tomaron 3 muestras semanales de leche materna de una sola donante durante 28 semanas. Las 84 muestras obtenidas, se sembraron en diferentes medios de cultivo. Se aislaron 578 cepas bacterianas. Se estudió la producción de sustancias antimicrobianas, mediante ensayos en gota y en pocillos. Las 101 cepas productoras de inhibidores de tipo bacteriocina fueron identificadas mediante ADNr 16S. Las cepas pertenecían solo a 3 filos y 11 géneros. Atendiendo a las propiedades funcionales (crecer en agar bilis/esculina, a alta concentración de sal y bajo pH) y seguridad (no ser hemolíticas, no hidrolizar ADN, y ausencia de genes de resistencia antimicrobianos) se seleccionaron 13 cepas para posteriores estudios. Se realizó un estudio de biodiversidad de la leche materna mediante secuenciación masiva, detectándose Streptococcus como grupo predominante en muchas de las muestras. Otros grupos relevantes fueron Staphylococcus, Rothia o Veillonella.Three weekly samples of breast milk were taken from a single donor during 28 weeks. The 84 samples obtained were plate count in different media. 578 bacterial strains were isolated. The production of antimicrobial substances was studied by spot-on-a-lawn and agar well assays. The 101 strains that produced bacteriocin-like substances were identified using 16S rDNA. The strains belonged to only 3 phyla and 11 genera. According to their functional characteristics (growth on bile /aesculin agar, at high salt concentration and low pH) and safety (lack of hemolytic and DNAase activities, and absence of antimicrobial resistance genes), 13 strains were selected for further studies. The bacterial diversity of milk samples was studied by high-throughput sequencing analysis. Streptococcus was the main bacterial group detected in many of the milk samples. Other relevant bacterial groups detected were Staphylococcus, Rothia or Veillonella. Tesis Univ. Jaén. Departamento de Ciencias de la Salud
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- 2020
49. Antibacterial Properties of Triethoxysilylpropyl Succinic Anhydride Silane (TESPSA) on Titanium Dental Implants
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Meritxell Molmeneu, Miquel Punset, Maria Godoy-Gallardo, Francisco Javier Gil, Judit Buxadera-Palomero, Universitat Politècnica de Catalunya. Departament de Ciència i Enginyeria de Materials, Universitat Politècnica de Catalunya. BBT - Biomaterials, Biomecànica i Enginyeria de Teixits, and Universitat Internacional de Catalunya
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Polymers and Plastics ,02 engineering and technology ,biofilm ,chemistry.chemical_compound ,0302 clinical medicine ,Silane ,Lactobacilos ,Bacteriocinas ,Titanium ,Implantes dentales ,biology ,Lactobacillus salivarius ,Biofilm ,Succinic anhydride ,Adhesion ,021001 nanoscience & nanotechnology ,Antimicrobial ,Titanio ,Materials biomèdics ,Infection ,0210 nano-technology ,silane ,chemistry.chemical_element ,Bacterial adhesion ,616.3 ,Enginyeria dels materials [Àrees temàtiques de la UPC] ,Triethoxysilylpropyl succinic anhydride (TESPSA) ,Article ,lcsh:QD241-441 ,03 medical and health sciences ,lcsh:Organic chemistry ,Infección ,titanium ,Implants dentals ,Dental implants ,technology, industry, and agriculture ,Titani ,030206 dentistry ,General Chemistry ,biology.organism_classification ,bacterial adhesion ,Antibacterial ,Lactobacillus ,Streptococcus sanguinis ,antibacterial ,chemistry ,Titani -- Aplicacions mèdiques ,Biofilms ,Lactobacil·làcies ,Bactericides ,Infecció ,triethoxysilylpropyl succinic anhydride (TESPSA) ,Biomedical materials ,Nuclear chemistry - Abstract
Infections related to dental implants are a common complication that can ultimately lead to implant failure, and thereby carries significant health and economic costs. In order to ward off these infections, this paper explores the immobilization of triethoxysilylpropyl succinic anhydride (TESPSA, TSP) silane onto dental implants, and the interaction of two distinct monospecies biofilms and an oral plaque with the coated titanium samples. To this end, titanium disks from prior machining were first activated by a NaOH treatment and further functionalized with TESPSA silane. A porous sodium titanate surface was observed by scanning electron microscopy and X-ray photoelectron spectroscopy analyses confirmed the presence of TESPSA on the titanium samples (8.4% for Ti&ndash, N-TSP). Furthermore, a lactate dehydrogenase assay concluded that TESPSA did not have a negative effect on the viability of human fibroblasts. Importantly, the in vitro effect of modified surfaces against Streptococcus sanguinis, Lactobacillus salivarius and oral plaque were studied using a viable bacterial adhesion assay. A significant reduction was achieved in all cases but, as expected, with different effectiveness against simple mono-species biofilm (ratio dead/live of 0.4) and complete oral biofilm (ratio dead/live of 0.6). Nevertheless, this approach holds a great potential to provide dental implants with antimicrobial properties.
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- 2020
50. Optimization of the production of bacteriocines from lactic bacteria in wastewater from cassava starch industry
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Tomoto, Aruani Letícia da Silva, Gomes, Simone Damasceno, Arruda, Priscila Vaz de, and Sene, Luciane
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Agroindustry residues ,Bacteriocin ,Lactobacillus fermentum ,Lactic acid bacteria ,ENGENHARIA AGRICOLA [CIENCIAS AGRARIAS] ,Leuconostoc mesenteroides ,Bacteriocinas ,Resíduos agroindustriais ,Bactérias do ácido lático - Abstract
Submitted by Neusa Fagundes (neusa.fagundes@unioeste.br) on 2020-10-13T17:17:37Z No. of bitstreams: 2 Aruani_Tomoto2020.pdf: 2782501 bytes, checksum: 1fdb55f0b70a5ec202223d86c0987d63 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Made available in DSpace on 2020-10-13T17:17:37Z (GMT). No. of bitstreams: 2 Aruani_Tomoto2020.pdf: 2782501 bytes, checksum: 1fdb55f0b70a5ec202223d86c0987d63 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2020-02-17 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES Bacteriocins are antimicrobial peptides produced from lactic acid bacteria, which act against pathogenic bacteria and can be used as biopreservatives in food. Residues from cassava processing are usually associated with the presence of lactic acid bacteria, and can be used as a substrate for the isolation of lactic acid bacteria and as a culture medium for the production of bacteriocins. In this sense, the objective of this work was to optimize the production of bacteriocins in wastewater from the cassava starch industry, by lactic acid bacteria isolated from the residue of the cassava processing. Initially, a lactic acid bacteria was isolated from the liquid residue of the cassava flour industry, and then its potential for the production of bacteriocins was evaluated. Along with the strain of lactic bacteria isolated in the present work, a strain of Leuconostoc mesenteroides was also used, already isolated from the same residue and with proven bacteriocin production capacity. The isolated strain was identified by morphological and biochemical tests and by 16S genetic sequencing (V3-V4), being identified as Lactobacillus fermentum, with 99.48% homology. To select the factors that influenced the production of bacteriocins by L. mesenteroides and L. fermentum,experimental designs of the Plackett-Burman (PB) were carried out, with 5 factors (sucrose, yeast extract, potassium phosphate, magnesium sulfate, and Tween 80), with an incubation time of 36 hours, at 30 °C, and agitation of 100 rpm. The factors defined in the PB in 90%, for both strains, were: sucrose, yeast extract, and Tween 80. Then, kinetic tests were performed for both strains, in the total time of 35 h, with samples taken every 5 h, to identify the best fermentation time for the production of bacteriocins. Both strains showed the highest production in 20 hours of cultivation. Having defined the significant factors of PB for the production of bacteriocins and the best fermentation time, the Central Rotational Composite Design (CRCD) was performed for the strains of L. fermentum and L. mesenteroides, in order to optimize the production of bacteriocins. The factors for DCCR were: sucrose, yeast extract, and Tween 80, fermentation time of 20 hours, temperature of 30 °C, and agitation of 100 rpm. In the DCCR tests, the response surfaces and the significant effects of the independent variables on the dependent variable (production of bacteriocins) were evaluated to establish a statistical model to optimize the process. The results indicated that the best bacteriocin production for L. fermentum and L. mesenteroides was 11,751.03 and 3693.34 AU/mL, respectively. Finally, the co-culture of the two strains was evaluated; however, the production of bacteriocins decreased, demonstrating that the L. fermentum and L. mesenteroides strains showed incompatibility. Bacteriocinas são peptídeos antimicrobianos produzidos a partir de bactérias láticas, que agem contra bactérias patogênicas, podendo ser utilizadas como biopreservantes nos alimentos. Os resíduos do processamento da mandioca normalmente estão associados com a presença de bactérias láticas, podendo assim ser utilizados como substratos para o isolamento de bactérias láticas e como meio de cultivo para a produção de bacteriocinas. Nesse sentido, o objetivo deste trabalho foi otimizar a produção de bacteriocinas em água residuária de indústria de fécula de mandioca, por bactérias láticas isoladas do próprio resíduo do processamento da mandioca. Inicialmente, foi feito o isolamento de uma bactéria lática a partir do resíduo líquido da indústria de farinha de mandioca, e então avaliado seu potencial para a produção de bacteriocinas. Juntamente com a cepa de bactéria lática isolada no presente trabalho, utilizou-se também uma cepa de Leuconostoc mesenteroides, já isolada do mesmo resíduo e que apresentava capacidade comprovada de produção de bacteriocinas. A identificação da cepa isolada foi realizada por testes morfológicos, bioquímicos e por sequenciamento genético 16S (V3-V4), sendo identificada como Lactobacillus fermentum, com homologia de 99,48%. Para selecionar os fatores que influenciavam nas produções de bacteriocinas por L. mesenteroides e L. fermentum foram realizados delineamentos experimentais do tipo Plackett-Burman (PB), com 5 fatores (sacarose, extrato de levedura, fosfato de potássio, sulfato de magnésio e Tween 80), com tempo de incubação de 36 horas, a 30 °C e agitação de 100 rpm. Os fatores significativos no PB a 90%, para ambas as cepas, foram: sacarose, extrato de levedura e Tween 80. Na sequência, foram realizados ensaios cinéticos para ambas as cepas, no tempo total de 35 h, com amostras retiradas a cada 5 h, para identificar o melhor tempo de fermentação para a produção de bacteriocinas. As duas cepas apresentaram a maior produção em 20 h de cultivo. Definidos os fatores significativos do PB para a produção de bacteriocinas e o melhor tempo de fermentação, foi realizado o Delineamento Composto Central Rotacional (DCCR) para as cepas de L. fermentum e L. mesenteroides, a fim de otimizar a produção de bacteriocinas. Os fatores para o DCCR foram: sacarose, extrato de levedura e Tween 80, tempo de fermentação de 20 horas, temperatura de 30 °C e agitação de 100 rpm. Nos ensaios do DCCR foram avaliadas as superfícies de respostas e os efeitos significativos das variáveis independentes sobre a variável dependente (produção de bacteriocinas), para estabelecer um modelo estatístico para otimizar o processo. Os resultados indicaram que as melhores produções de bacteriocinas para L. fermentum e L. mesenteroides foram de 11751,03 e 3693,34 AU/mL, respectivamente. Por último foi avaliada a cocultura das duas cepas; no entanto, a produção de bacteriocinas diminuiu, demonstrando que as cepas de L. fermentum e L. mesenteroides apresentaram incompatibilidade.
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- 2020
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