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In this study, cinnamon (Cinnamomum zeylanicum), thyme (Thymus vulgaris) and Schinus molle essential oils (at 125, 250 and 500 µg/mL) were encapsulated in chitosan nanoparticles by ionotropic gelation. Their antimicrobial activity against Staphylococcus aureus ATCC 25923, Enterococcus sp., Escherichia coli ATCC 25922, Klebsiella pneumoniae (BLEE +) and Pseudomona aeruginosa carbapenemase producer was evaluated. The obtained nanoparticles exhibited a regular distribution and spherical shape with size range of 19.7 to 361 nm as observed by using a laser light scattering equipment. It was found that the studied chitosan nanoparticles with essential oils showed high antimicrobial effect than the chitosan and essential oils alone. Enterococcus sp. was the most sensitive bacteria and S. aureus the most resistant. Chitosan nanoparticles and chitosan nanoparticles with cinnamon and thyme essential oils were capable to inhibit growth of Enterococcus sp. and K. pneumoniae. This study demonstrated that chitosan nanoparticles with essential oils were effective against some foodborne pathogens.

Jacquinia macrocarpa, a plant native to northwestern Mexico, has an inhibitory effect against phytopathogenic fungi. Previous studies have shown that the butanolic extract of J. macrocarpa causes retardation and atrophy in mycelial growth of Fusarium verticillioides. However, the action mechanism of this extract is unknown. We used a proteomics approach to understand the inhibitory effect of J. macrocarpa butanolic extract, based on differential protein accumulation in F. verticillioides. Proteins were extracted from F. verticillioides cultured in Czapek broth with and without 202.12 μg/mL (IC50) of butanolic extract of J. macrocarpa. Thirty-eight protein spots showing statistically significant changes (ANOVA, p < 0.01) and at least a 2-fold change in abundance between experimental conditions were analyzed by mass spectrometry. Identified proteins were grouped into different biological processes according to Gene Ontology, among them were amino acid metabolism, protein folding and stabilization, protein degradation, protein transport, carbohydrate metabolism, oxidative stress response, and miscellaneous. This work is the first report of changes in the proteomic profile of F. verticillioides exposed to the J. macrocarpa extract. This information provides new insights into the inhibitory mechanism of the extract and represents a starting point for dissection of the fungal response against the J. macrocarpa extract components.

Chitosan (CS) nanosystems have potential applications for the control of microorganisms in the medical, environmental, and agrifood fields. In vivo and in vitro assays of CS nanosystems have experienced increased activity due to improved physicochemical properties, biological activity, and reactivity. Hence, it is important to determine whether their application involves toxicological risks. The aim of this study was to evaluate the mutagenic, cytotoxic, phytotoxic, and in vivo antifungal activity of chitosan-pyrrole-2-carboxylic acid nanobiocomposites (CS-PCA). The CS-PCA nanoparticles were synthesized by means of the nanoprecipitation technique with a size and ζ-potential of 502 ± 72 nm and + 54.7 ± 15.0 mV, respectively. According to the Ames test, no evidence of mutagenic activity was observed in Salmonella typhimurium strains. The cytotoxic assay showed that the incorporation of PCA into the CS matrix increased the toxic effect on ARPE-19 cells. However, fluorescence microscopy of ARPE-19 cells did not reveal morphostructural changes allusive to cell injury. CS-PCA exhibited strong phytotoxicity on lettuce seeds and the complete inhibition of seed development. The antifungal assay demonstrated that the CS-PCA delayed Aspergillus niger infection in tomato fruit until day 3; however, its use for the pre-treatment of seeds might exert adverse effects on plant development.

The fungus

In this work, an innovative strategy for raw chicken burger preservation, based on methanol–HCl extracts of octopus (Octopus vulgaris) (OVE) and squid (Dosidicus gigas) (DGE) skin pigments, was evaluated at 4 °C for 12 days. Burgers were prepared and divided into six groups: the control without any extract (CON), the control with 0.03% α-tocopherol (CET), and those containing 0.05% (OVE1, DGE1) and 0.1% (OVE2, DGE2) octopus and squid pigment extract, respectively. OVE yielded a higher rate of pigments with antioxidant activity (DPPH, ABTS, and ORAC) than DGE. The highest antimutagenic activity was detected in DGE according to the Ames’ Salmonella test. OVE1 and DGE1 burgers maintained lower pH values and were less sensitive to lipid oxidation (peroxide, anisidine, and total oxidation values). Evaluation of microbial growth by total bacterial count, lactic acid bacteria, Enterobacteriaceae spp., and fungi showed that OVE1 and DGE1 delayed bacterial contamination. The overall sensory quality was maintained for longer in the OVE- and DGE-supplemented chicken burgers than CON burgers. This study showed that OVE and DGE have potential as antioxidant and antimicrobial additives in chicken products.

9 pages, 3 figures, 2 tables.-- This is an Open Access article distributed under the terms of the Creative Commons Attribution License, Cancer represents the second leading cause of death worldwide, therefore, the search for chemoprotective agents is on the rise. The muscle of white shrimp (Litopenaeus vannamei) is one of the species analyzed as it has been reported as a source of compounds with antiproliferative activity. The aim of this study was to evaluate the effect of shrimp muscle-isolated compounds on cell proliferation and morphology of human cancer cell lines. The muscle underwent a process of extraction and fractionation of compounds; their effect on cell viability assays (MTT) on lung adenocarcinoma (A549), prostate carcinoma (22 Rv-1), invasive breast adenocarcinoma (MDA MB 231), colon carcinoma (HTC 116), cervix adenocarcinoma (HeLa) and non-cancerous retinal cells (ARPE-19) was measured. Morphological changes were observed using fluorescence microscopy and chemical structure data was obtained using nuclear magnetic resonance. Fraction named C5 showed the highest antiproliferative activity on HCT-116 and MDA-MB-231, without significantly affecting the control cells. Subfractions C5-3 and C5-4 presented significant antiproliferative potential in MDA-MB-231; this cell line showed morphological changes that could be related to apoptosis, and spectroscopic analysis revealed the presence of b-carotene and eicosapentaenoic acid in C5, nevertheless, further studies are needed to determine the effect of each compound

La mancha marrón (Bipolaris oryzae) es una de las enfermedades que afecta al cultivo del arroz (Oryza sativa L.) y actualmente se investiga la posibilidad de utilizar productos naturales como el quitosano el control de la misma. Este compuesto presenta una alta actividad antifúngica, la cual depende de su masa molecular, grado de acetilación, concentración, entre otros. Muchos investigadores han comprobado la actividad antimicrobiana del quitosano sobre algunos hongos. El efecto directo de un quitosano de baja masa molecular sobre el hongo Bipolaris oryzae fue demostrado en este trabajo. Cambios en las hifas, en los tubos germinativos fueron observados a través de un microscopio óptico. Posteriormente, se realizaron observaciones mediante la técnica de microscopía electrónica de barrido (MEB) en la fase de crecimiento apical del hongo. Los resultados por microscópico óptico evidenciaron alteraciones en las hifas del hongo tales como: malformaciones dado por acortamiento y engrosamiento, mientras que en las observaciones por MEB se observaron distorsión en las hifas.

Chitosan (85% deacetylated, viscosity &gt, 400 MPa, and molecular weight of 570.3 kDa)/squid gelatin hydrolysates (SGH) were prepared by incorporating SGHs (10%, 20%, and 40%) into chitosan films. SGH were obtained from squid skin gelatin by hydrolysis with Alcalase. The effects of adding SGH on the physical, chemical structure, mechanical, degradability, antioxidant, and antifungal properties of the chitosan films were evaluated. Films containing SGH were opaquer and more colored than the reference. Scanning electron microscope imaging showed that the surface sections of the CH/SGH films were smooth and homogeneous, though a small amount of insoluble microparticles was observed. Atomic force microscopy indicated that the surface roughness of the chitosan films increased with the addition of SGH. Fourier-transform infrared spectroscopy and nuclear magnetic resonance spectroscopy suggested an excellent compatibility of the components due to hydrogen bonding. The flexibility and in vitro degradability of the films increased as the SGH content increased. The 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate acid and 1,1-diphenyl-2-picrylhydrazyl scavenging rate of films increased with the addition of SGH. Moreover, films containing 20% SGH improved the fungistatic activity against Aspergillus parasiticus of chitosan films. The chitosan/SGH composite films have the potential for use in food packaging.

Urea is one of the most widely used nitrogen fertilizers. However, it is lost to the environment via processes such as denitrification, surface runoff, volatilization, and leaching. In this paper, a novel material is reported on, with low production cost and avoiding the use of harmful solvents, with a pastille morphology developed by a simple method from a mixture of wheat gluten and urea, with potential use as a prolonged-release system of urea (PRSU). The PRSU obtained was characterized by scanning electron microscopy, kinetics of water absorption, equilibrium water content (EWC), Fourier-transform infrared (FT-IR) spectroscopy analysis, and release kinetics. The PRSU diameter was 2.46 cm, and its thickness was 0.17 cm. The PRSU showed physical and structural characteristics such as micropores and hollow fractions in its structure. In addition, the wheat gluten pastille is classified as a swelling material and demonstrated an EWC of 58.47 ± 1.50%. FT-IR analysis of the samples showed hydrogen-bond interactions between the amino and carbonyl groups in the urea and the wheat gluten proteins. Laboratory tests showed that the system can release 97% of the urea within 8–10 h. These results showed that the PRSU presents suitable characteristics for its application as a fertilization alternative for carrying out better agronomic practices.

The aim of this study was to investigate the in vitro effect of an antifungal fraction obtained from Jacquinia macrocarpa plant (JmAF) in the generation of reactive oxygen species (ROS) and...

In this research, we conducted a systematic evaluation of the synthesis parameters of a multi-responsive core-shell nanocomposite (Fe3O4 nanoparticles coated by poly(N-isopropylacrylamide) (PNIPAM) in the presence of chitosan (CS) (Fe3O4@PNIPAM-CS). Scanning electron microscopy (SEM) was used to follow the size and morphology of the nanocomposite. The functionalization and the coating of Fe3O4 nanoparticles (Nps) were evaluated by the ζ-potential evolution and Fourier Transform infrared spectroscopy (FTIR). The nanocomposite exhibited a collapsed structure when the temperature was driven above the lower critical solution temperature (LCST), determined by dynamic light scattering (DLS). The LCST was successfully shifted from 33 to 39 °C, which opens the possibility of using it in physiological systems. A magnetometry test was performed to confirm the superparamagnetic behavior at room temperature. The obtained systems allow the possibility to control specific properties, such as particle size and morphology. Finally, we performed vincristine sulfate loading and release tests. Mathematical analysis reveals a two-stage structural-relaxation release model beyond the LCST. In contrast, a temperature of 25 °C promotes the diffusional release model. As a result, a more in-depth comprehension of the release kinetics was achieved. The synthesis and study of a magnetic core-shell nanoplatform offer a smart material as an alternative targeted release therapy due to its thermomagnetic properties.

RESUMEN La producción de orégano es de relevancia económica en el noroeste de México. Sin embargo, los productores para obtener altos rendimientos recurren a la fertilización química, pero su mal uso, agudiza la salinidad. Lippia palmeri crece de manera natural en suelos áridos, pobres en materia orgánica, alta salinidad y temperatura en el noroeste de México. En el contexto de una agricultura sustentable, los microorganismos mantienen la fertilidad del suelo e incrementan la productividad de la planta. Actualmente existe interés en proponer biofertilizantes en la agricultura de alta intrusión salina y elevadas temperaturas para el cultivo de orégano. Las Halobacterias Promotoras del Crecimiento de Plantas (HPCP), se han destacado por beneficiar a los cultivos nutrimentalmente y mitigar el efecto de la salinidad. El objetivo del presente trabajo consistió en identificar termo- y halo-tolerantes HPCP asociadas a la rizosfera de L. palmeri; se evaluó la actividad solubilizadora de fosfatos, producción de ácidos orgánicos, sideróforos y fijación de nitrógeno; se identificaron mediante el gen ARNr-16S aquellas con alta actividad evaluándose su efecto en la germinación y longitud radicular. Quince diferentes colonias sobresalieron al crecer en NaCl (0.25, 0.50 y 0.75 M) a 35 y 45 °C, destacando tres bacterias identificadas: Bacillus amyloliquefaciens, Bacillus subtilis y Bacillus licheniformis. El efecto en la longitud radicular es significativo por la aplicación de B. amyloliquefaciens. Estudios relacionados con la promoción vegetal deben ser considerados en posteriores estudios. Este es el primer informe de B. amyloliquefaciens como una bacteria fijadora de nitrógeno asociada a L. palmeri. ABSTRACT The production of oregano is of economic relevance in northwestern Mexico. However, to obtain high yields, producers resort to chemical fertilization, but its misuse increases salinity. Lippia palmeri Watts is a species of oregano that naturally grows in arid soils with poor organic matter, high salinity and temperature in the northwestern Mexico. In the context of sustainable agriculture, microorganisms activate soil fertility and increase plant productivity. Currently there is interest in proposing biofertilizers in the agriculture with high saline intrusion and temperatures for the cultivation of oregano. The Plant Growth Promoting Halobacteria (HPCP) have stood out by the beneficiary of the nutritious crops and mitigate the effect of the salinity. The goal of this work was to identify HPCP associated to the rhizosphere of L. palmeri, thermo and halotolerant; phosphate solubilizing activity, organic acid production, siderophores and nitrogen fixation were evaluated; the highest activity colonies were identified by the rRNA-16S gene and the effect on germination and root length was evaluated. Fifteen different colonies stood out when growing in NaCl (G.25, G.5G and G.75 M) at 35 and 45 °C, from which three bacteria were identified: Bacillus amyloliquefaciens, Bacillus subtilis and Bacillus licheniformis. The effect on root length was significant for B. amyloliquefaciens. Studies related to plant promotion should be involved in subsequent studies. This is the first report of Bacillus amyloliquefaciens as a nitrogen fixing bacteria associated with Lipia palmeri.

Nanoparticles based on chitosan modified with epigallocatechin gallate (EGCG) were synthetized by nanoprecipitation (EGCG-g-chitosan-P). Chitosan was modified by free-radical-induced grafting, which was verified by Fourier transform infrared (FTIR). Furthermore, the morphology, particle size, polydispersity index, and zeta potential of the nanoparticles were investigated. The grafting degree of EGCG, reactive oxygen species (ROS) production, antibacterial and antioxidant activities of EGCG-g-chitosan-P were evaluated and compared with those of pure EGCG and chitosan nanoparticles (Chitosan-P). FTIR results confirmed the modification of the chitosan with EGCG. The EGCG-g-chitosan-P showed spherical shapes and smoother surfaces than those of Chitosan-P. EGCG content of the grafted chitosan nanoparticles was 330 μg/g. Minimal inhibitory concentration (MIC) of EGCG-g-chitosan-P (15.6 μg/mL) was lower than Chitosan-P (31.2 μg/mL) and EGCG (500 μg/mL) against Pseudomonas fluorescens (p &lt, 0.05). Additionally, EGCG-g-chitosan-P and Chitosan-P presented higher Staphylococcus aureus growth inhibition (100%) than EGCG at the lowest concentration tested. The nanoparticles produced an increase of ROS (p &lt, 0.05) in both bacterial species assayed. Furthermore, EGCG-g-chitosan-P exhibited higher antioxidant activity than that of Chitosan-P (p &lt, 0.05) in 2,2′-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and ferric-reducing antioxidant power assays. Based on the above results, EGCG-g-chitosan-P shows the potential for food packaging and biomedical applications.

In this work, we used a sequential method of synthesis for gold-silver bimetallic nanoparticles with core@shell structure (Au@AgNPs). Rumex hymenosepalus root extract (Rh), which presents high content in catechins and stilbenes, was used as reductor agent in nanoparticles synthesis. Size distribution obtained by Transmission Electron Microscopy (TEM) give a diameter mean of 36 nm for Au@AgNPs, and 24 nm for gold nanoparticles (AuNPs). The geometrical shapes of NPs were principally quasi-spherical. The thickness of silver shell over AuNPs are around 6 nm and covered by active biomolecules onto surface. Microstructural characterization included high angle annular dark field images (HAADF) recorded with a scanning transmission electron microscope (STEM), Energy-Dispersive X-ray Spectroscopy (EDS), X-Ray Diffraction (XRD), UV-Vis Spectroscopy, and Zeta Potential. Also, a growth kinetic curve analysis using the Gompertz model for Staphylococcus aureus (Gram-positive), Escherichia coli (Gram-negative), and Candida albicans (yeast) were carried out for Au@AgNPs and monometallic AuNPs and AgNPs. Interestingly, Gompertz analysis indicates that Au@AgNPs present a higher effect on the growth kinetic of microorganisms than shown by monometallic nanoparticles.

In this work, we used a sequential method of synthesis for gold–silver bimetallic nanoparticles with core@shell structure (Au@AgNPs). Rumex hymenosepalus root extract (Rh), which presents high content in catechins and stilbenes, was used as reductor agent in nanoparticles synthesis. Size distribution obtained by Transmission Electron Microscopy (TEM) gives a mean diameter of 36 ± 11 nm for Au@AgNPs, 24 ± 4 nm for gold nanoparticles (AuNPs), and 13 ± 3 nm for silver nanoparticles (AgNPs). The geometrical shapes of NPs were principally quasi-spherical. The thickness of the silver shell over AuNPs is around 6 nm and covered by active biomolecules onto the surface. Nanoparticles characterization included high angle annular dark field images (HAADF) recorded with a scanning transmission electron microscope (STEM), Energy-Dispersive X-ray Spectroscopy (EDS), X-Ray Diffraction (XRD), UV–Vis Spectroscopy, Zeta Potential, and Dynamic Light Scattering (DLS). Fourier Transform Infrared Spectrometer (FTIR), and X-ray Photoelectron Spectroscopy (XPS) show that nanoparticles are stabilized by extract molecules. A growth kinetics study was performed using the Gompertz model for microorganisms exposed to nanomaterials. The results indicate that AgNPs and Au@AgNPs affect the lag phase and growth rate of Escherichia coli and Candida albicans in a dose-dependent manner, with a better response for Au@AgNPs

Dentro de las enzimas antimicrobianas reportadas, las lisozimas y las enzimas tipo lisozimas procedentes de diversas fuentes naturales han mostrado actividad antibacteriana y antifúngica, haciéndolas atractivas como nuevas alternativas para controlar los microorganismos patógenos. Aunque las enzimas antimicrobianas se han propuesto ampliamente en la industria alimentaria y en la protección de cultivos, su uso implica algunas desventajas, como la inactivación por inhibidores o productos químicos o condiciones de procesamiento, los altos costos de producción y purificación, y problemas de solubilidad e inestabilidad. La tecnología de inmovilización enzimática es una herramienta prometedora capaz de reducir estos inconvenientes, particularmente cuando está destinada a trabajar en medios sólidos. Esta revisión muestra el estado del arte sobre la actividad de la lisozima contra bacterias y hongos, centrándose en los mecanismos de acción involucrados. Además, también se discuten los aspectos y características más mportantes de las lisozimas y su posible aplicación tecnológica, incluida la aplicación de matrices poliméricas a base de quitosano para la inmovilización de las enzimas antimicrobianas.

This study aimed to determine the ability of Fusarium verticillioides in developing mechanisms to counteract the antifungal effect of a fraction from Jacquinia macrocarpa plant extract (JmAF), as well as the morphological and physiological changes that occur during its exposure. The fungus was exposed to JmAF during consecutive periods. A culture sample was taken weekly to determine radial growth, spore germination and size, and fungal β-1,3-glucanase activity. The results showed that, in the beginning, the radial growth decreased by 85.8%, and spore germination was delayed. As the exposure continued, the fungus showed a recovery, to some extent, in its original characteristics. However, the radial growth of the fungus continued to be inhibited (42.9%) throughout the experiment (7 weeks). The β-1,3-glucanase activity also was inhibited by 36.4% during the first week of exposure to JmAF. However, the activity was recovered after 7 weeks of exposure.

In patients with age-related macular degeneration (AMD), the crucial retinal pigment epithelial (RPE) cells are characterized by mitochondria that are structurally and functionally defective. Moreover, deficient expression of the mRNA-editing enzyme Dicer is noted specifically in these cells. This Dicer deficit up-regulates expression of Alu RNA, which in turn damages mitochondria—inducing the loss of membrane potential, boosting oxidant generation, and causing mitochondrial DNA to translocate to the cytoplasmic region. The cytoplasmic mtDNA, in conjunction with induced oxidative stress, triggers a non-canonical pathway of NLRP3 inflammasome activation, leading to the production of interleukin-18 that acts in an autocrine manner to induce apoptotic death of RPE cells, thereby driving progression of dry AMD. It is proposed that measures which jointly up-regulate mitophagy and mitochondrial biogenesis (MB), by replacing damaged mitochondria with “healthy” new ones, may lessen the adverse impact of Alu RNA on RPE cells, enabling the prevention or control of dry AMD. An analysis of the molecular biology underlying mitophagy/MB and inflammasome activation suggests that nutraceuticals or drugs that can activate Sirt1, AMPK, Nrf2, and PPARα may be useful in this regard. These include ferulic acid, melatonin urolithin A and glucosamine (Sirt1), metformin and berberine (AMPK), lipoic acid and broccoli sprout extract (Nrf2), and fibrate drugs and astaxanthin (PPARα). Hence, nutraceutical regimens providing physiologically meaningful doses of several or all of the: ferulic acid, melatonin, glucosamine, berberine, lipoic acid, and astaxanthin, may have potential for control of dry AMD.

Essential oils (EO) have been studied as a possible substitute of fungicides. EO have been loaded in polymeric nanoparticles to prevent their degradation and enhance antifungal activity. In this work was to prepared chitosan nanoparticles with Schinus molle EO by ionotropic gelation. The bionanocomposites were characterized by scanning electronic microscopy (SEM), dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FTIR). The antifungal activity was evaluated in different growth stages of A. parasiticus (spore germination, radial growth and spore viability) and the effect in aflatoxin production was analyzed by using affinity chromatography columns from VICAM. DLS results showed that the Np-CS and Np-CS-SEO diameters were 361.9 ± 31.4 and 516.9 ± 45.4 nm, respectively. According to SEM, the NPs presented spherical shape and the zeta potential was slightly decreased when Schinus molle EO was incorporated. The Np-CS-SEO (62.5–500 μg mL−1) showed a high inhibition (>80%) on spore germination of A. parasiticus at 12 h of incubation, while, radial growth was not inhibited for these NPs. At a concentration of 500 μg mL−1, Np-CS-SEO inhibited up to 59% the aflatoxin production. Depending on concentration, the Np-CS-SEO can be considered as an alternative to control A. parasiticus.

Foodborne diseases have increased, and with it, the interest to discover new natural antimicrobials; the use of aromatic plants, due to the extraction and use of the essential oil (EO), are widely studied and with great biological activity. However, studies with hydrosols (HS) from aromatic plants are limited. The aim in this study was to evaluate the antibacterial activity of HS from Lippia palmeri plant against the bacterial pathogen L. monocytogenes. HS was obtained by hydrodistillation and fractionation thereof by open column chromatography. The antibacterial activity was performed by disk diffusion. The inhibitory concentration (IC50) was estimated using the PROBIT survival analysis. Ampicillin was used as control. To evaluate the diameter and cellular damage, optical microscopy and epifluorescence were used, respectively. The characterization was performed by spectroscopy. HS showed IC50 of 224 μL/mL and from HS two fractions were obtained. The fraction with the highest activity showed an IC50 of 125 mg/mL and rosmarinic acid and a phthalate derivative were identified from this fraction. HS, showed bioactivity against L. monocytogenes. Therefore, this would be a candidate for use as an active ingredient in the disinfection of food and areas in contact with them.

In this study, particles of chitosan-carrageenan (Cs-Crg) and chitosan-carrageenan-lysozyme (CS-Crg-LZ) were synthesized by ionic complexation. The particles were analyzed by atomic force microscopy, dynamic light scattering and FT-IR, and the percentage of association of lysozyme was determined. The biological activity of the particles was evaluated by viability assays of Aspergillus parasiticus spores and cytotoxicity in ARPE-19 cells. The effect on subcellular structures was analyzed by fluorescence microscopy. The addition of lysozyme reduced the size of the particles. The size and Z potential of the synthesized particles were 725±5.5 and 250±8.1 nm and 28.7±1.0 and 21.6±0.8 mV for CS-Crg and CS-Crg-LZ, respectively. CS-Crg-LZ and CS-Crg particles exhibited a higher (p

Preventive and curative activity of postharvest treatments with chitosan nanoparticles (CS) and chitosan biocomposites loaded with pepper tree essential oil (CS-PEO) against anthracnose were evaluated on Avocado (Persea americana) cv. Hass artificially inoculated in rind wounds. After 10 days of storage significant preventive and curative activity against Colletotrichum gloeosporioides was observed with the absence of internal damage by applying CS and CS-PEO. Quality parameters like water losses and firmness changes were assessed on fruit treated. CS and CS-PEO were effective to reduce water losses and firmness losses.

Recent studies have demonstrated that the micro and nanoparticles of chitosan (CS) have an in vitro antifungal effect against filamentous fungus that are of importance in food. This study was made to evaluate the antifungal activity of chitosan nanoparticles, pepper tree essential oil (PEO), and chitosan biocomposites loaded with pepper tree essential oil (CS-PEO), on the in vitro growth of Colletotrichum gloeosporioides. The particles were obtained by nanoprecipitation and the size and superficial charge (Z potential) were evaluated using dynamic light dispersion analysis (DLS). The mutagenic potential and the acute toxicity were also evaluated. The effect on the radial growth, spore’s germination, viability, and damage to the membrane´s integrity, were determined. The effect on the kinetic growth parameters was also determined. Results showed that the CS and CS-PEO particles diameter was 341.2 ± 12.40 and 355.3 ± 25.3 mm, respectively. In vitro assays showed both nanoparticles with a high inhibition potential on C. gloeosporioides, and low mutagenicity and toxicity. At a concentration of 0.160 mg/mL, the CS-PEO biocomposite presented a greater (P

Farmed shrimp Litopenaeus vannamei, one of the most consumed seafood in the planet, is a source of antiproliferative extracts still to be fully characterized. This study the isolation and identification of these antiproliferative compounds. From a chloroform-soluble extract from shrimp muscle, hexane- and methanol-soluble fractions were obtained and tested for antiproliferative activity (MTT), a bioassay that guided the fractionation and isolation of bioactive fractions using open column chromatography. MeOH-soluble fraction resulted bioactive and was subjected to further fractionation from which one subfraction outstand for being highly active against prostate cancer cell line. Antiproliferative effects were evaluated using colorimetric assays and cell morphology observations. Further chromatographic procedures resulted in sub-fractions from which one was effective in causing DNA damage and F-actin polymerization, which suggests cellular collapse and apoptosis. According to the structural chemical characterization carried out, dioctyl phthalate, eicosapentaenoic acid, and an indolocarbazole alkaloid type of compound were identified. This last compound, which resulted majorly responsible for the bioactivity, was not found reported in the available databases. Pure EPA control was used to compare it with the subfraction, observing greater activity in the subfraction than when EPA was used, suggesting that another compound different from EPA is providing the highest activity; but, more investigation is needed for a full chemical and structural characterization.

The oxidative stress damage on cells is an example of roles in the pathogenesis of different degenerative diseases and the search of compounds that can slow this oxidation is continuous. The aim of this work was to obtain bioactive fractions from wild shrimp (Litopenaeus stylirostris) muscle, in order to evaluate their protective capacity and chemo-structurally characterize them. ABTS and DPPH, and FRAP assays suggested that bioactive fractions possess free radical-scavenging capacity, and reducing power, respectively. An inhibitory effect observed on AAPH-induced hemolysis and results from an H2O2-derived radicals-scavenging assay (retinoprotective) suggest that these fractions can exert their protective activity in human cells. UV–Vis, fluorescence, 13C-, 1H-NMR, and ESI-MS studies performed on the most bioactive fraction, suggests that their main components are eicosapentaenoic acid, dioctyl phthalate, and a possibly novel indolocarbazole alkaloid derivative. These results suggest that these compounds are good candidates to further investigations as possible chemoprotective agents.

Heavy metals are toxic especially when they are introduced into the environment due to anthropogenic activities such as metallurgy, mining, and tanning. Removing these pollutants has become a worldwide concern since they cannot be degraded into nontoxic forms causing extended effects in the ecosystems. The use of an Aspergillus australensis was evaluated in order to remove Cu2+ from simulated wastewater. The fungus was isolated from river sludges contaminated with heavy metals and was first evaluated for the determination of Cu2+ tolerance levels. Microscopic fluorescence analysis was carried out to determine the effect of Cu2+ presence on the viability, cellular components, polyhydroxyalkanoates production, and oxidative stress of the fungus, as a response to the stress caused by exposure to metal. In order to achieve copper removal, the A. australensis biomass was produced using batch cultures, and the mycelium was immobilized on a textile media in order to compare the copper-removal efficiency of live or dead biomass. The optimal values of pH and temperature for biomass production were established by using a surface response analysis. Live immobilized biomass was capable of removing Cu2+ from 1.54 ± 0.19 to 2.66 ± 0.26 mg of copper/ g of dry biomass, while values of 1.93 ± 0.03 to 2.36 ± 0.29 mg of copper/g of dry biomass were observed when dead biomass was used. As was expected, copper removal using biomass varied depending on the pH and temperature used.

The aim of this study was to investigate the

The antibacterial activity of low-density polyethylene/adhesive resin (10%)/epigallocatechin gallate (0.03, 0.5, 5, and 10%) extrusion cast films were evaluated against Staphylococcus aureus (gram positive) and Pseudomonas sp. (gram negative) via direct contact and in solid and liquid culture media. The epigallocatechin gallate concentration in the active films was established per the in vitro antibacterial analysis of pure epigallocatechin gallate against S. aureus and Pseudomonas sp. The epigallocatechin gallate migration profile and concentration required to inhibit bacterial growth in broth were determined. In addition, the effects of epigallocatechin gallate and adhesive resin on the mechanical, color, and thermal film properties were investigated. The results indicate that pure epigallocatechin gallate inhibited the growth of both bacteria. However, only the films with 10 wt% epigallocatechin gallate (with and without adhesive resin) induced morphological changes and inhibited the growth of S. aureus (p

Antioxidant, anticarcinogenic, and antimicrobial properties have been reported for ferulic acid (FA), therefore, its application interests both food and agriculture research. FA was immobilized in different chitosan (CS) matrices, physicochemicaly characterized and the effect on Aspergillus parasiticus ecological parameters evaluated. Nanoparticles (Nparticles), microparticles (Mparticles) and microcapsules (Mcapsules) of 35–40 nm, 30–40 μm, and 20 μm, respectively were obtained; FA incorporation in matrices affected their morphology, physicochemical properties, and their fungistatic effect. The effect of the particles was dependent on the matrix exposed. Nparticles and Mparticles showed high FA immobilization efficiency as well as a good fungistatic effect against A. parasiticus: Radial growth at 168 h was 28.46 ± 1.01 and 28.84 ± 1.36 and the inhibition of spore germination at 30 h was 57.44 ± 0.22 and 55.74 ± 2.19, for Nparticles and Mparticles, respectively compared with control cultures. Abnormalities in mycelium, hyphae, and spores morphology were observed, as well as low sporulation due particle interaction with the fungus.

Chitosan was functionalized with epigallocatechin gallate (EGCG) by a free radical-induced grafting procedure, which was carried out by a redox pair (ascorbic acid/hydrogen peroxide) as the radical initiator. The successful preparation of EGCG grafted-chitosan was verified by spectroscopic (UV, FTIR and XPS) and thermal (DSC and TGA) analyses. The degree of grafting of phenolic compounds onto the chitosan was determined by the Folin-Ciocalteu procedure. Additionally, the biological activities (antioxidant and antibacterial) of pure EGCG, blank chitosan and EGCG grafted-chitosan were evaluated. The spectroscopic and thermal results indicate chitosan functionalization with EGCG; the EGCG content was 25.8mg/g of EGCG grafted-chitosan. The antibacterial activity of the EGCG grafted-chitosan was increased compared to pure EGCG or blank chitosan against S. aureus and Pseudomonas sp. (p

The antimicrobial activity of films made of poly(l-lactic acid)/poly(l-lactic acid) grafted maleic anhydride(copolymer)/epigallocatechin gallate(EGCG) blend was determined. The effect of epigallocatechin gallate incorporation (0.03, 0.5, 5, and 10 wt%) as a natural antibacterial was determined by direct contact, solid and liquid culture media. The film antimicrobial activity was evaluated against two bacteria (gram-negative: Pseudomonas spp.; gram-positive: Staphylococcus aureus). The copolymer was prepared and characterized by Fourier transform infrared analysis and Molau test. Furthermore, the degree of grafting was determined. The epigallocatechin gallate migration profile through the films were determined and the minimum epigallocatechin gallate concentration in films required to show antibacterial activity was evaluated. The results showed that only the films with 10 wt% epigallocatechin gallate significantly affected ( p

Sorbent materials of biological origin are considered as an alternative to the use of traditional methods in order to remove heavy metals. Interest in using these materials has increased over the past years due to their low cost and friendliness to the environment. The objective of this study was to synthesize and characterize cross-linked beads made of chitosan, alginate, and mycelium of a copper-tolerant strain of Aspergillus australensis. The acute toxicity of the biocomposite beads was assessed using brine shrimp Artemia salina nauplii and the phytotoxicity was determined using lettuce (Lactuca sativa) and chili pepper &rsquo, Anaheim&rsquo, (Capsicum annuum) seeds. The biosorption capacity for copper removal in simulated wastewater was also evaluated. Results showed that the biosorbent obtained had a maximal adsorption of 26.1 mg of Cu2+ per g of biocomposite, and removal efficiency was around 79%. The toxicity of simulated residual water after treatment with the biocomposite showed low toxicity toward seeds, which was highly dependent on the residual copper concentration. The toxicity of the biocomposite beads to A. salina was considered medium depending on the amount of the biocomposite, which was attributed to low pH. Biocomposite shows promise as biosorbent for the removal process of heavy metals.

A wide variety of chitosan (CS) biomaterials have been loaded with different antimicrobial agents to improve the activity of CS against phytopathogenic fungi. Recently, the antimicrobial activity of 1H-pyrrole-2-carboxylic acid (PCA) has been reported as a secondary metabolite of Streptomyces griseus, which was identified as the main bioactive compound in the biological control. However, it is sensitive to light and its activity against filamentous fungi has not yet been reported. The aim of the present research work was to evaluate the biological activity of CS-PCA biocomposites for the control of Aspergillus niger. CS-PCA biocomposites were obtained through nanoprecipitation. In vitro antifungal activity was determined by viability assay, spore germination, morphometric analysis of spores and hyphae, and the analysis of cellular components by fluorescence microscopy. CS-PCA showed an average size and Z potential of 502 ± 72 nm and + 54.7 ± 15 mV, respectively. Micrographs demonstrated well-distributed biocomposites with an apparently spherical shape. A new signal at 1473 cm−1 in the FT-IR spectrum of the CS-PCA biocomposite was observed, confirming the presence of PCA in the composition of the CS-PCA nanosystem. CS-PCA biocomposites reduced the spores’ viability by up to 58%. Effects on fungi morphometry, observed as an increase in the spores’ average diameter, swelling, distortion, and an increase in the branching of hyphae, were observed. Fluorescence analysis showed oxidative stress and membrane and cell wall damage, mainly at early growth stages. The inhibitory effect against CS-resistant fungi, such as A. niger, opens a door for the control of CS-sensitive fungi.

Chitosan nanoparticles (CS) and chitosan/pepper tree (Schinus molle) essential oil (CS-EO) bionanocomposites were synthesized by nanoprecipitation method and the in vitro antifungal activity against Aspergillus parasiticus spores was evaluated. The shape and size were evaluated by scanning electron microscopy (SEM) and dynamic light scattering (DLS). The surface charge was determined by assessing the zeta potential and the inclusion of essential oil in bionanocomposites using Fourier transform infrared spectroscopy (FT-IR). The effect on cell viability of the fungus was evaluated using the XTT technique and morphometric analysis by image processing. SEM and DLS analysis indicated that spherical particles with larger diameters for CS-EO biocomposites were observed. Zeta potential values were higher (+11.1 ± 1.60 mV) for CS nanoparticles. Results suggest a chemical interaction between chitosan and pepper tree essential oil. The highest concentration of CS-EO complex caused a larger (40–50%) decrease in A. parasiticus viability. The inclusion of pepper tree oil in CS nanoparticles is a feasible alternative to obtain antifungal biocomposites, where the activity that each compound presents individually is strengthened.

Micro- and nanotechnology are tools being used strongly in the area of food technology. The electrospray technique is booming because of its importance in developing micro- and nanoparticles containing an active ingredient as bioactive compounds, enhancing molecules of flavors, odors, and packaging coatings, and developing polymers that are obtained from food (proteins, carbohydrates), as chitosan, alginate, gelatin, agar, starch, or gluten. The electrospray technique compared to conventional techniques such as nanoprecipitation, emulsion-diffusion, double-emulsification, and layer by layer provides greater advantages to develop micro- and nanoparticles because it is simple, low cost, uses a low amount of solvents, and products are obtained in one step. This technique could also be applied in the agrifood sector for the preparation of controlled and/or prolonged release systems of fertilizer or agrochemicals, for which more research must be conducted.

Lignin conveys several important and useful characteristics to starch films depending on the lignin MW, extraction procedure, and lignin botanical source. In this study, lignin was obtained from durum wheat straw through the organosolv process, followed by fractionation according to solubility in alcohol. The alcohol-soluble lignin (ASL) was then used to prepare starch–ASL films. The mechanical properties, thermal stability, water solubility, color, and antioxidant activity of the resulting films were evaluated, and the starch–ASL films were also analyzed by means of SEMand attenuated total reflection infrared spectroscopy (ATR-IR). A procedure, to incorporate ASL, was developed and used to produce homogenous surfaces in starch–ASL films; agglomerations or undissolved particles of lignin were not observed in the starch matrix at microscopic level. ASL promoted significant decrease of the tensile strength (TS) and elastic modulus (EM), but an increase of elongation at break (EB) in films. Thermal analysis of the starch–ASL films showed high resistance to thermal degradation, due to the incorporation of ASL. In addition, the starch– ASL films exhibited antioxidant activity (2,2-diphenyl-1-picrylhydrazyl [DPPH]), which increased with increasing ASL content.

Aspergillus and Fusarium are the fungi genera most frequently isolated from cereal grains and other commodities. They are capable of producing mycotoxins, which can affect the human and animal health. Synthetic fungicides have been used to control these fungi, nevertheless, they have acquired resistance and other alternatives are necessary since they now need higher amounts. Therefore, the aim of this study was to evaluate the efficacy of cinnamon, clove and thyme essential oils (EOs) alone and encapsulated in chitosan on the radial growth, spore germination and mycotoxin production by Fusarium verticillioides and Aspergillus parasiticus. The composition of the EOs was determined by gas chromatography mass spectrometry (GC-MS). EOs inhibited radial growth and spore germination of both fungal species better than when they were encapsulated, plus, they reduced mycotoxin production. The major components were eugenol in cinnamon and clove EO (70 and 63%, respectively) and 2-methyl-5-(1-methyethyl)-phenol (46.2%) in thyme EO. The microparticles with clove and thyme EO showed good surface charges, higher than +30 mV and their average size for the three types of microparticles was about 750 nm. Our findings suggest that EOs both alone and encapsulated in chitosan have a fungistatic effect on Fusarium verticillioides and Aspergillus parasiticus.

Synthesis of nanocomposites from antimicrobial biopolymers such as chitosan (CS) and lysozyme (LZ) is an important and promising area in bionanotechnology. Chitosan-lysozyme (CS-LZ) nanoparticles (NPs) were prepared by the nanoprecipitation method, using commercial chitosan of 153 kDa. TEM and dynamic light scattering (DLS) analysis were carried out to evaluate the morphology, size, dispersion, and Z potential. Association efficiency of lysozyme was determined using Coomassie blue assay. The antifungal activity of NPs against Aspergillus parasiticus was evaluated through cell viability (XTT), germination and morphometry of spores, and reducing sugars production; the effects on membrane integrity and cell wall were also analyzed. NPs' size were found in the range of 13.4 and 11.8 nm for CS-LZ and CS NPs, respectively, and high Z potential value was observed in both NPs. Also, high association of lysozyme was presented in the CS matrix. With respect to the biological responses, CS-LZ NPs reduced the viability of A. parasiticus and a strong inhibitory effect on the germination of spores (100% of inhibition) was observed at 24 h in in vitro assays. CS-LZ and CS NPs affected the membrane integrity and the cell wall of spores of fungi with respect to control, which is consistent with the low amount of reducing sugars detected. CS-LZ NPs prepared by nanoprecipitation promise to be a viable and safe alternative for use in biological systems, with a possible low or null impact to humans and biota. However, the potential benefits and the environmental and health implications of NPs need to be globally discussed due to its possible negative effects.