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Bacteria that are capable of accumulating lipids in their cells as storage compounds can also produce polyhydroxyalkanoates of high technological value, depending on the specific culture conditions. The objective of this study was to utilize crude glycerol from biodiesel (CGB) as a substrate, which is a major byproduct from biodiesel production, to produce lipophilic compounds. Bacillus megaterium INCQS 425 was cultivated and evaluated for the production of lipophilic compounds and the properties of these compounds were investigated. Cultivation of the bacteria in a medium with a C:N ratio of 0.60:1 favored the accumulation of lipids by (17.5%) comprising mainly palmitic acid (13.08%), palmitoleic (39.48%), and especially oleic acid (37.02%), which imparts good characteristics to biodiesel. Meanwhile, cultivation of the bacteria in a medium with a C:N ratio of 4:1 favored the accumulation of polyhydroxyalkanoates (PHA) (3.31gL-1) mainly comprising medium and long chain PHA. Low crystallinity (

This objective of this work was to monitor the EPS production during the growth of Spirulina sp. LEB-18, evaluate the productivity and to characterize the exopolymers obtained on pilot-scale under outdoor conditions. The production of crude EPS occurred in all phases of biomass growth and was approximately ten folds higher than that biomass concentration of Spirulina sp. LEB-18 at the end cultivation, demonstrating the importance of the use of supernatant after harvesting of Spirulina to obtain high value bioproducts. The EPS extracted by Spirulina sp. LEB-18 are typically heteropolymers with one high molecular weight fraction (polysaccharides) with potential to be utilized as an alternative bioflocculant and another fraction of lower molecular mass (proteins). The presence of uronic acids, pyruvates and acyl groups of carbohydrates or carboxylic groups of amino acids in protein moiety is the main responsible for overall negative charge of EPS, which is also of biotechnological importance. Moreover, due to the pseudoplastic behavior of the solutions and high thermal stability, the obtained EPS can be widely applied in several industrial sectors, thus determining its technological and market potentiality.

Este trabalho traz um estudo sobre produção de nanopartículas de amido de mandioca (SNP), por hidrólise ácida, e sua eficiência como aditivo para lubrificantes. O nanolubrificante foi preparado utilizando o óleo Rocol® Ultracut 250, adicionado de SNP’s em concentrações variadas (0,05, 0,5, 1,00 e 1,25% m/m). As nanopartículas foram caracterizadas quanto ao Potencial Zeta e análise termogravimétrica (TGA). O nanolubrificante (Rocol® Ultracut 250 + SNP), foi submetido ao teste pino-disco, onde foram medidos o coeficiente de atrito (µ) e a taxa de desgaste (w), antes e depois da adição das SNP’s. A adição de nanopartículas de amido ao lubrificante levou a melhorias significativas no desempenho do mesmo, com redução do coeficiente de atrito em torno de 30% e aumento da taxa de desgaste em mais de 700%.

The presence of metals in industrial effluents has become a major environmental problem since these residues are often disposed of in lakes or rivers. Aiming to recover contaminated areas the remediation by washing using biosurfactants appears as an alternative technique that features low toxicity to the environment. This paper aims to evaluate the efficiency in iron removal within a synthetic effluent, utilizing a biosurfactant. This was produced in a bioreactor (37°C, 200 rpm, 0.5 vvm) derived from a papaya peel aqueous extract and the Bacillus subtilis UFPEDA strain 86. The fermentation tests revealed that this Bacillus is a great producer for the biosurfactant. The tests also displayed that the papaya peel extract is a viable substrate for the production of biosurfactant by this strain. Among the results found, in 24 hours of cultivation, the highest concentration of biomass and product was obtained, of 2.17 ± 0.04 g.L-1 and 2.88 ± 0.01 g.L-1, respectively. The biosurfactant provided a Critical Micellar Concentration (CMC) of 20 mg.L-1. The batch method was used in the obtainment of removal data, in which a series of solutions at different concentrations of iron ions were exposed to different amounts of biosurfactant, both raw and purified, at a temperature of 25 °C, under agitation (200 rpm) and pH ~ 6.3. A multivariate experimental design was carried out in the presence of crude and purified biosurfactant. The results demonstrated significant interactions involved for the following independent variables: concentration of iron ions, concentration of biosurfactant and the treatment time. The iron removal percentages varied between 47.2% and 95.82% in the presence of the raw biosurfactant, and between 37.01% to 91.94% in the presence of the purified surfactant. The Langmuir adsorption model was the better adjusted, providing a maximum adsorption capacity at approximately 10 mg.g-1. La presencia de metales en los efluentes industriales se ha convertido en un problema ambiental importante ya que estos residuos a menudo se eliminan en lagos o ríos. Con el objetivo de recuperar áreas contaminadas, la remediación mediante el lavado con biosurfactantes aparece como una técnica alternativa que presenta baja toxicidad para el medio ambiente. El presente trabajo tuvo como objetivo evaluar la eficiencia en la eliminación de hierro en un efluente sintético, utilizando un biosurfactante producido en un biorreactor (37°C, 200 rpm, 0.5 vvm), del extracto acuoso de la cáscara de papaya y la cepa de Bacillus subtilis UFPEDA 86. Las pruebas fermentativas mostraron que este Bacillus es un buen productor de biosurfactantes y que el extracto de la cáscara de papaya es un sustrato viable para la producción de biosurfactantes por esta cepa. Entre los resultados encontrados, en 24 horas de cultivo, se obtuvo la mayor concentración de biomasa y producto, de 2.17 ± 0.04 g.L-1 y 2.88 ± 0.01 g.L-1, respectivamente. El biosurfactante producido mostró una concentración micelar crítica (CMC) de 20 mg.L-1. SEl método por lotes se utilizó en la obtención de datos de eliminación, en el que una serie de soluciones a diferentes concentraciones de iones de hierro se expusieron a diferentes cantidades de biosurfactantes, tanto crudos como purificados, a una temperatura de 25 ° C, bajo agitación (200 rpm) y pH ~ 6.3. E llevó a cabo una planificación experimental multivariada, en presencia de biosurfactante crudo y purificado, donde los resultados mostraron que las interacciones entre las variables independientes (concentración de iones de hierro, concentración de biosurfactante y el tiempo de tratamiento) fueron significativas para ambos. Los porcentajes de eliminación de hierro variaron entre 47.2 y 95.82%, en presencia del bisurfactante crudo y de 37.01 a 91.94% en presencia del biosurfactante purificado. El modelo de adsorción de Langmuir fue el mejor ajustado, con la capacidad de adsorción máxima estimada en 10 mg.g-1. A presença de metais em efluentes industriais tornou-se um grande problema ambiental, uma vez que esses resíduos são frequentemente descartados em lagos ou rios. Com o objetivo de recuperar áreas contaminadas, a remediação por lavagem com biossurfactantes aparece como uma alternativa que apresenta baixa toxicidade para o meio ambiente. O presente trabalho objetivou avaliar a eficiência na remoção do ferro em um efluente sintético, utilizando um biossurfactante produzido em um biorreator (37°C, 200 rpm, 0.5 vvm), a partir do extrato aquoso da casca de mamão e da cepa Bacillus subtilis UFPEDA 86. Os ensaios fermentativos mostraram que esse Bacillus é um bom produtor de biossurfactante e que o extrato da casca de mamão é um substrato viável para a produção de biossurfactante por esta cepa. Dentre os resultados encontrados, em 24 horas de cultivo, obteve-se a maior concentração de biomassa e produto, de 2,17 ± 0,04 g.L-1 e 2,88 ± 0,01 g.L-1, respectivamente. O biossurfactante produzido apresentou Concentração Micelar Crítica (CMC) de 20 mg.L-1. Ensaios em batelada foram utilizados para obtenção dos dados de remoção, nos quais uma série de soluções em diferentes concentrações de íons de ferro foram expostas a diferentes quantidades de biossurfactante, bruto e purificado, a uma temperatura de 25 ° C, sob agitação (200 rpm) e pH ~ 6,3. Foi realizado um planejamento experimental multivariado, na presença de biossurfactante bruto e purificado, onde os resultados mostraram que as interações entre as variáveis independentes (concentração dos íons de ferro, concentração de biossurfactante e o tempo de tratamento) foram significantes para ambos. As porcentagens de remoção do ferro variaram entre 47,2 e 95,82%, na presença do bissurfactante bruto e de 37,01 a 91,94% na presença do biossurfactante purificado. O modelo de adsorção de Langmuir foi o melhor ajustado, sendo a capacidade máxima de adsorção estimada em 10 mg.g-1.

This study sought to evaluate influence of nitrogen availability on cell growth, biomass composition, production, and the properties of polyhydroxyalkanoates during cultivation of microalgae Chlorella minutissima, Synechococcus subsalsus, and Spirulina sp. LEB-18. The cellular growth of microalgae reduced with the use of limited nitrogen medium, demonstrating that nitrogen deficiency interferes with the metabolism of microorganisms and the production of biomass. The biochemical composition of microalgae was also altered, which was most notable in the degradation of proteins and chlorophylls and the accumulation of carbonaceous storage molecules such as lipids and polyhydroxyalkanoates. Chlorella minutissima did not produce these polymers even in a nitrogen deficient environment. The largest accumulations of the polyhydroxyalkanoates occurred after a 15 days culture, with a concentration of 16% (dry cell weight) produced by the Synechococcus subsalsus strain and 12% by Spirulina sp. LEB-18. Polyhydroxyalkanoates produced by Synechococcus subsalsus and Spirulina sp. LEB-18 presented different thermal and physical properties, indicating the influence of producing strain on polyhydroxyalkanoates properties. The polymers obtained consisted of long chain monomers with 14 to 18 carbon atoms. This composition is novel, as it has not previously been found in PHAs obtained from Synechococcus subsalsus and Spirulina sp. LEB-18.

The objective of this study was to evaluate the efficacy of methods used to extract polyhydroxyalkanoates from Spirulina sp. LEB-18 microalgae and to examine the influence of these methods on the purity, properties, and composition of the polymers. Polyhydroxyalkanoates were characterized by Fourier transform infrared spectroscopy (FTIR), molecular mass, degree of crystallinity, and monomer composition. The efficacy of the extraction methods varied, with polyhydroxyalkanoate accumulation. between 6.10 and 9.80%, and degrees of purity between 63.51 and 93.62%. Using sodium hypochlorite in the initial stage of the extraction increased accumulation, while using methanol at the end of the process increased the purity of the polymers. The molecular mass and crystallinity index of the polyhydroxyalkanoates varied, showing that the extraction methods interfered with polymer properties. The composition of polyhydroxyalkanoates was also influenced by the extraction, with varying percentages of monomers identified. The copolymers of the polyhydroxyalkanoates obtained are formed by the monomers 11-hydroxyhexadecanoate, in a higher proportion, hydroxyheptanoate and hydroxytetradecanoate, demonstrating that Spirulina sp. LEB-18 is capable of producing medium and long chain polymers. The detection of these monomer blocks in the polyhydroxyalkanoate structure of this microalga is an important scientific novelty because these monomer blocks are constituents of new polymers. An indirect relationship (R2 = 0.8044) was observed between the percentage of the 11-hydroxyhexadecanoate monomer and the degree of crystallinity of polyhydroxyalkanoates obtained by the different methods. This suggests that obtaining the polymer with medium- and long-chain monomers contributes to reduction of crystallinity.

Microalgae-based biorefinery coupled with effluent treatment (MBBET) is an approach that makes biomass production economically advantageous. It can produce value-added products from a circular bioeconomy perspective for a variety of industries. Although the global microalgae market is growing at a rapid rate of 7.39% per year and 70–90% of world's technological information is consolidated in patents, this source of technical data is still underexamined in the microalgae field. Technological prospecting is a powerful tool that provides insight into expanding knowledge and innovation in companies, providing inputs for competitive intelligence, improving decision-making, and forecasting technological changes. Thus, this review aims to fill this research gap by presenting a bibliometric analysis of patents conjugated with a natural language processing (NLP) text-mining approach to transforming raw big data into useful information. The state-of-the-art prospective patents on MBBET are disclosed, demonstrating the potential of this integration, its historic-technological trends, the different effluents treated, and bioproducts of market interest. The research was conducted using the Espacenet and Orbit® databases. The data were recovered from patent documents from the last 20 years using a combination of the keyword “Microalgae” and code C02F3 (Biochemical effluent treatment), where 422 documents were recovered from Espacenet and 664 from Orbit®. In this paper, we show that patents are a noteworthy source of information for the advancement of microalgal biorefinery areas, especially when they are compared to scientific articles. Although biotechnological potential of algal biomass is still underexploited, technological gaps and active technologies are highlighted. MBBET is a promising key to mitigate global environmental challenges and is an expression of the new paradigm of water-food-energy. Future challenges are proposed to sketch perspectives on new avenues for technological improvements.

The conditions of storage, cultivation and maintenance of microbial cultures should preserve the microbiological homogeneity, phenotypic and genotypic characteristics to ensure better reproducibility of metabolic production. To evaluate the influence of the storage condition on the composition of cell fatty acids, genetic profile and biochemical characteristics of Xanthomonas campestris pv. mangiferaeindicae IBSBF 2103, as well as, to identify its relationship with the yielding and viscosity of the xanthan gum produced, this study monitored the strain preserved in two simple and widely used conditions, ultra-freezer (−80 °C) and refrigeration (3–8 °C) during 5 months. Were identified and quantified 13 fatty acids. The cells preserved at −80 °C showed more stable concentration of all fatty acids, producing more xanthan gum and with higher viscosity. The chromosomal analysis obtained with the enzyme XbaI revealed 17 distinct fragments with maximum size of 485 kilobases, without variations among the subcultures maintained in both storage conditions. The X. campestris pv. mangiferaeindicae subcultures preserved at −80 °C showed less pronounced phenotypic variations, which had positive influence in the qualitative and quantitative characteristics of the xanthan gum produced.

The objective was to evaluate the effect of reusing Zarrouk's medium on a Spirulina sp. LEB 18 culture by determining kinetic parameters, chemical composition, biofuels, and thermal characterization. Cultivation was performed in a raceway bioreactor for 7 days, the supernatant was reused for four cycles. Culturing the microalga in the reused medium resulted in a cellular yield of 2.30 g L−1 (control) and 2.04, 1.89, 1.73, and 1.15 g L−1 for four cycles with no influence on cell growth and productivity. Biomass with high contents of carbohydrates (58.00%, 3rd cycle), phycocyanin (2.47 mg mL−1, 1st cycle), and saturated fatty acids (60.13%, 4th cycle) were obtained with an increase in the profiles of C16:0 (45.85%) and C18:2n6 (47.40%) in the 1st cycle. The reuse of Zarrouk's medium allowed obtaining biomass with reduced cost and differentiated characteristics, allowing the exploration of commercially important biomolecules by the completion of up to four cycles.

In the present study, mixed and axenic submerged cultures of Cupriavidus necator and Xanthomonas campestris were performed for simultaneous and individual PHA and XG productions using palm oil (Elaeis guineensis) as substrate. Rotational Central Compound Design (RCCD) was successfully used in the optimization of individual productions of PHA (3.39 g L−1, Mw = 692.6 kDa) and XG (1.77 g L−1, Mw = 36.6 × 105 kDa). Novel simultaneous production of PHA (6.43 g L−1, Mw = 629.2 kDa) and XG (1.98 g L−1, Mw = 25.0 × 105 kDa), executed in bacterial co-cultivation, revealed to be a successful strategy to increment polymer synthesis, especially PHA. XG bioconversions followed a general trend of lower production in co-culture. Culture configurations also altered polymers properties and characteristics.

This study aimed to evaluate the properties of xanthan gum produced by Xanthomonas campestris pv. campestris 1866 and 1867 from lignocellulosic agroindustrial wastes. XG was produced using an orbital shaker in a culture medium containing coconut shell (CS), cocoa husks (CH), or sucrose (S) minimally supplemented with urea and potassium. The XG production results varied between the CS, CH, and S means, and it was higher with the CH in strains 1866 (4.48 g L−1) and 1867 (3.89 g L−1). However, there was more apparent viscosity in the S gum (181.88 mPas) and the CS gum (112.06 mPas) for both 1866 and 1867, respectively. The ability of XGCS and XGCH to emulsify different vegetable oils was similar to the ability of XGS. All gums exhibited good thermal stability and marked groups in the elucidation of compounds and particles with rough surfaces.

In this study, we investigated the cellular fatty acid profiles of different Xanthomonas pathovars producing xanthan gum and explored the fatty acid composition to identify chemical markers of xanthan gum productivity and quality. Three Xanthomonas pathovars were studied. The fermentation was conducted for 168 h. Samples from the fermented medium were collected for extraction, quantification, and characterization of xanthan. The unsaturated/saturated (U/S) fatty acid ratio in Xanthomonas cells during fermentation was correlated with production, viscosity, and molecular weight of the gum obtained at each 24 h. The Xanthomonas axonopodis pv manihotis 290 strain showed a higher U/S ratio for major cell fatty acids (C16:1ω7/C16:0) as compared with the other two strains; this high ratio was directly associated with xanthan production. No correlation was observed between cellular fatty acid composition and characteristics of xanthan synthesized. Thus, it was possible to determine a production chemical marker for xanthan gum in Xanthomonas strains.

The aim of this study was to obtain and characterize the nanocellulose of different vegetable sources: coconut fiber, licuri fiber, corn stover and pulp of eucalyptus commercial as well as incorporate those into a polymeric matrix cassava starch plasticized glycerol. Different formulations were developed to evaluate the maximum concentrations of nanocellulose that could be incorporated to the films, in order to obtain homogeneous materials. Moreover, the incorporation of nanocellulose with aspect ratios L/D (24 – 54) and degree of crystallinity (55 – 70%) in different mechanical properties, barrier, moisture and water activity (Aw) were availed. Films containing nanocellulose, independent of font vegetable source, showed a reduction of water vapor permeability (9.14 – 49.83%). Nanocellulose crystals, cassava starch, along with the plasticizer were responsible for up to 78.13 – 826.86% increase in the Young's modulus and 137.58 - 181.61% of maximum tension bionanocomposites compared to the reference film (LDPE). Mechanical, physical and barrier properties of the developed film indicated that the addition of these nanocellulose independent of font vegetable source compounds modified their properties significantly (p

In recent years there has been a great worldwide interest in sustainability. Various researches in the area of polymeric and composite materials have been developed to ensure environmental preservation and provide a better standard of living to society. Cellulose nanoparticles are biodegradable, have a high degree of crystallinity and other properties justifying their use as mechanical reinforcement material in bionanocomposites. The aim of this study is to prepare and characterize nanoparticles extracted pulp cellulose from corn stover by acid hydrolysis. The chemical composition of corn stover cellulose was determined. The fibers were treated with NaOH, bleached using sodium hypochlorite and (CH3COOH/NaOH) to remove residual lignin. Then the nanoparticles were obtained by acid hydrolysis and calculated your yield. Morphological analysis of nanoparticles was performed by transmission electron microscopy (TEM). The index of crystallinity was obtained by X-ray diffraction (XRD) in addition, thermogravimetric (TGA) and FTIR analysis. Corn stover consists of 45.50% cellulose, 27.59% hemicellulose and lignin of 6.77%. This lignocellulosic source is viable raw material for obtaining nanoparticles by acid hydrolysis (H2SO4), reaching a yield of 64% of nanoparticles with a degree of crystallinity of 55.04% and L/D of 54.7 ± 24, which can provide improvement in mechanical and barrier properties for the development of bionanocomposites.

Xanthan gum (XG) is a microbial exopolysaccharide that occupies a prominent place in the market because of its unique properties compared with other microbial gums. When lignocellulosic materials such as sugarcane bagasse (SCB) are used as a carbon source, the degradation of the SCB material can be partial, retaining microfibrils of cellulose in the fermentation broth. These microfibrils can be incorporated into the XG structure. The aim of this work was to select the best concentration of SCB to produce XG and to analyze the characteristics of the biopolymer obtained. The XG produced in the best condition was added to biodegradable films as a reinforcing agent. The SCB was evaluated at the following concentrations: 2, 4, 6, 8 and 10% w/w. The XG produced with 4% w/w SCB provided the best XG, not only for production but also for polymer characteristics. Visualization with transmission electron microscopy (TEM) established the presence of microfibrils in the polysaccharide structure, and the incorporation of XG with microfibrils provided a flexible film with enhanced mechanical properties.

Registros históricos demonstram que as plantas medicinais eram utilizadas por vários povos, uma dessas o Zingiber officinal também conhecido como gengibre, encontrada em florestas tropicais, sendo nativo do sudeste Asiático. O gengibre é uma especiaria amplamente usada para aliviar sintomas como inflamação, doenças reumáticas e desconfortos gastrintestinais. Seus extratos e seus principais compostos pungentes, os gingeróis, têm mostrado varias atividades biológicas, incluindo efeito como agentes antineoplásicos, antiespasmódicos e antieméticos, inibidores de enzimas, anti-hemorrágicos, antifúngicos, protetores de células neurais, anti reumáticos, microbicidas, antiinflamatórios e antioxidantes. Para tanto, realizou-se uma prospecção com o intuito de obter um panorama mundial sobre o mercado tecnológico do gengibre, na qual foi feita uma pesquisa a partir de palavras-chave do tema em estudo com códigos da classificação internacional na base de dados do European Patent Office (EPO), se atendo em informações como os inventores, empresas envolvidas, evolução anual das patentes depositadas, a origem das tecnologias e distribuição por países.

Os polihidroxialcanoatos (PHAs) são os únicos polímeros de origem microbiana totalmente biodegradável. Eles são sintetizados por diversos microrganismos, possuindo, após extração, propriedades semelhantes ao polipropileno. O polihidroxibutirato (PHB) é o polímero mais comum da família dos PHAs e historicamente é o que tem sido mais estudado, ele é obtido a partir da bactéria Cupriavidus necator por fermentação da glicose em meio limitante de fonte de nitrogênio ou fósforo. Devido à importância econômica deste biopolímero, o objetivo deste trabalho foi analisar as potencialidades, características e evolução das competências tecnológicas, traduzidas através de documentos de patentes, no que diz respeito à obtenção do PHB no período de 1979 a 2010. Para tanto, foram analisados banco de dados do Espacenet, do Derwent Innovations Index, do United States Patent and Trademark Office e do Instituto Nacional de Propriedades Industrial. Foram realizadas buscas em relação à evolução anual das patentes depositadas, a origem da tecnologia, os detentores da tecnologia e principais inventores. Os códigos de Classificação Internacional de Patentes de maior incidência no Espacenet e no INPI são das classes C12 (bioquímica e mutações de engenharia genética) e C08L (composições de compostos orgânicos macromoleculares), respectivamente. Nas bases pesquisadas, as empresas depositaram mais documentos que as universidades e os centros de pesquisa, sendo os anos de 2006 e 2009 os de maior relevância. Dos países pesquisados, os Estados Unidos foi o que apresentou maior número de registros (34%). O Brasil ainda possui poucas patentes na área, sendo necessários mais incentivos que visem aumentar o cenário inovativo do país.

Simultaneous synthesis of polyhydroxyalkanoates (PHAs) and polyglutamic acid (PGA) was investigated in cultures of Cupriavidus necator IPT 026, C. necator IPT 027, C. necator IPT 029, and Bacillus megaterium INCQS 425 strains in a medium containing 2.0 % sucrose or crude glycerol from biodiesel (CGB), in an orbital shaker (35 °C, 180 rpm, 72 h). All the strains tested simultaneously produced PHA and PGA in a medium containing CGB. The C. necator IPT026 culture provided higher molecular mass PHA and PGA (1128.55 and 835.56 kDa, respectively). B. megaterium INCQS 425 promoted PGA production (1.90 g L-1) with higher crystalline melting temperature (84.04 °C) and higher initial decomposition temperature (247.10 °C). Furthermore, the latter culture promoted the production of medium- and long-chain PHA (0.78 g L-1) with high crystalline melting temperatures (∼170 °C) and high initial decomposition temperature (307.53 °C) and low degree of crystallinity (20.2 %). These characteristics render these PHAs more appropriate and suitable for processes that require high temperatures, such as extrusion, increasing the possibility of industrial applications, especially in the packaging sector.

Um destino para resíduos agro-industriais é usá-los como substratos fermentescíveis, diminuindo o custo na produção de produtos com alto valor agregado. Este trabalho avaliou a influência da natureza dos resíduos fermentescíveis e das cepas de Xanthomonas sobre a produção e propriedades do biopolímero resultante. A produção foi realizada em agitador orbital (250 rpm / 28 °C / 120 h) por fermentação de sacarose (controle), glicerina residual do biodiesel e resíduo líquido de sisal. Tanto a composição do substrato como as cepas mostraram um forte efeito sobre a produção (0,36-2,40 gL- 1), viscosidade aparente (13,73 para 36,31 mPa.s) e massa molecular (2,1-5,9 × 10(6) Da) da goma de xantana resultante, não influenciando o comportamento pseudoplástico de soluções aquosas dos biopolímeros. A destination for agro-industrial waste is to use them as fermentation substrates. This work was aimed at evaluating the influence of the nature of the waste fermented by two strains of Xanthomonason on the biopolymer properties. The production was performed in an orbital shaker (250 rpm / 28 °C / 120 h) by fermentation of sucrose (control), crude glycerin from biodiesel and sisal liquid waste. Both the fermented substrate composition and the strains had a strong impact on production (0.36 to 2.40 g.L- 1), apparent viscosity (13.73 to 36.31 mPa.s) and molecular mass (2.1 to 5.9 × 10(6) Da) of the resulting xanthan gum, but they did not affect the pseudoplastic behavior of aqueous biopolymers solutions.

p. 737-746 Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2014-04-29T13:53:35Z No. of bitstreams: 1 0104-66322013000400006.pdf: 323743 bytes, checksum: be46d44ac9517222f4d5a8b7c11c0dcb (MD5) Approved for entry into archive by LIVIA FREITAS (livia.freitas@ufba.br) on 2014-07-10T19:25:02Z (GMT) No. of bitstreams: 1 0104-66322013000400006.pdf: 323743 bytes, checksum: be46d44ac9517222f4d5a8b7c11c0dcb (MD5) Made available in DSpace on 2014-07-10T19:25:02Z (GMT). No. of bitstreams: 1 0104-66322013000400006.pdf: 323743 bytes, checksum: be46d44ac9517222f4d5a8b7c11c0dcb (MD5) Previous issue date: 2013-10 The production and rheological properties of xanthan gum from crude glycerin fermentation, a primary by-product of the biodiesel industry with environmental and health risks, were evaluated. Batch fermentations (28 °C/250 rpm /120 h) were carried out using crude glycerin, 0.01% urea and 0.1% KH2PO4, (% w/v), and compared to a sucrose control under the same operational conditions, using Xanthomonas campestris strain 2103 isolate from Brazil. Its maximal production by crude glycerin fermentation was 7.23±0.1 g·L-1 at 120 h, with an apparent viscosity of 642.57 mPa·s, (2 % w/v, 25 °C, 25 s-1), 70% and 30% higher than from sucrose fermentation, respectively. Its molecular weight varied from 28.2 to 36.2×106 Da. The Ostwald-de-Waele model parameters (K and n) indicated a pseudoplastic behavior at all concentrations (0.5 to 2.0 %, w/v) and temperatures (25-85 °C), while its consistency index indicated promising rheological properties for drilling fluid applications. Therefore, crude glycerin has potential as a cost-effective and alternative substrate for non-food grade xanthan production.

The effects of aeration and agitation on the properties and production of xanthan gum from crude glycerin biodiesel (CGB) by Xanthomonas campestris mangiferaeindicae 2103 were investigated and optimized using a response surface methodology. The xanthan gum was produced from CGB in a bioreactor at 28 °C for 120 h. Optimization procedures indicated that 0.97 vvm at 497.76 rpm resulted in a xanthan gum production of 5.59 g L(-1) and 1.05 vvm at 484.75 rpm maximized the biomass to 3.26 g L(-1). Moreover, the combination of 1.05 vvm at 499.40 rpm maximized the viscosity of xanthan at 0.5% (m/v), 25 °C, and 25 s(-1) (255.40 mPa s). The other responses did not generate predictive models. Low agitation contributed to the increase of xanthan gum production, biomass, viscosity, molecular mass, and the pyruvic acid concentration. Increases in the agitation contributed to the formation of xanthan gum with high mannose concentration. Decreases in the aeration contributed to the xanthan gum production and the formation of biopolymer with high mannose and glucose concentrations. Increases in aeration contributed to increased biomass, viscosity, and formation of xanthan gum with greater resistance to thermal degradation. Overall, aeration and agitation of CGB fermentation significantly influenced the production of xanthan gum and its properties.