Abstract Introduction: From a microbiological point of view, Staphylococcus aureus is one of the main contaminants causing foodborne illnesses, with symptoms such as nausea, vomiting, diarrhea, abdominal cramps, joint or back pain and fatigue. Bacterial resistance of pathogenic bacteria has recently been found to be a public health problem. An alternative is the use of microencapsulated probiotics for the inhibition of pathogenic microorganisms such as Lactobacillus casei. Objective: Evaluate microencapsulated Lactobacillus casei ATCC 393® under in-vitro conditions simulating the gastrointestinal environment and the inhibitory potential on Staphylococcus aureus ATCC BAA 1708®. Materials and methods: Reconstitution, seeding and adjustment of the inoculum; antibiogram of the two bacterial strains; fermentation kinetics of Lactobacillus casei; identification of peptides, amino acids and lactic acid of the supernatant; resistance of Lactobacillus casei to different temperatures (37 °C and 45 °C); microencapsulation of Lactobacillus casei; study, characterization and exposure to simulated gastrointestinal conditions of the microencapsulate after 90 days of storage and production of Exopolysaccharides. Results: The results indicate inhibitory action of the Lactobacillus casei strain against pathogenic bacteria; exponential phase at 15 hours (MRS culture medium) and 18 hours (PRO culture medium); results of the microencapsulation study and analysis: viability 100 %; efficiency 84,64 %; humidity 4,0 %; solubility 99,8 %; wettability 2 min with 22 seconds; water activity 0,617 and particle size between 2,10 μm and 5,28 μm. Conclusion: It was concluded that the microencapsulated Lactobacillus casei showed inhibitory properties against the pathogenic strain.

Resumen Introducción: Desde un punto de vista microbiológico, Staphylococcus aureus es uno de los principales contaminantes causante de enfermedades de trasmisión alimentaria, con síntomas como náuseas, vómitos, diarrea, calambres abdominales, dolor articular o de espalda y fatiga. Recientemente, se ha encontrado resistencia bacteriana de bacterias patógenas siendo un problema de salud pública. Una alternativa es la utilización de probióticos microencapsulados para la inhibición de microorganismos patógenos como Lactobacillus casei. Objetivo: Evaluar Lactobacillus casei ATCC 393® microencapsulada bajo condiciones in vitro que simulan el ambiente gastrointestinal y potencial inhibitorio sobre Staphylococcus aureus ATCC BAA 1708®. Materiales y métodos: Reconstitución, siembra y ajuste de inóculo; antibiograma de las dos cepas bacterianas; cinética de fermentación de Lactobacillus casei; identificación de péptidos, aminoácidos y ácido láctico de sobrenadante; resistencia de Lactobacillus casei a diferentes temperaturas (37 °C y 45 °C); microencapsulación de Lactobacillus casei; estudio, caracterización y exposición a condiciones gastrointestinales simuladas del microencapsulado después de 90 días de almacenamiento y producción de Exopolisacáridos. Resultados: Los resultados indican acción inhibitoria de la cepa Lactobacillus casei frente a la bacteria patógena; fase exponencial a las 15 horas (medio de cultivo MRS) y a las 18 horas (medio de cultivo PRO); resultados del estudio y análisis del microencapsulado: viabilidad 100 %; eficiencia 84,64 %; humedad 4,0 %; solubilidad 99,8 %; humectabilidad 2 min con 22 segundos; actividad de agua 0,617 y tamaño de partícula entre 2,10 μm y 5,28 μm. Conclusión: Se concluyó que Lactobacillus casei microencapsulado presentó propiedades inhibitorias frente a la cepa patógena.

ABSTRACT Juçara fruits (Euterpe edulis Martius), an important palm tree native to the Atlantic Forest ecosystem, exhibit a rich diversity of microorganisms, including lactic acid bacteria (LAB). LAB are highly capable of synthesizing exopolysaccharides (EPS), which are extracellular carbohydrate biopolymers with techno-functional properties, and consequently, wide applicability. In the present study, the technical-functional information of the dextran produced by L. pseudomesenteroides JF17 was obtained by determining its physicochemical, rheological, water-holding, oil-holding, and emulsifying properties. Dextran-JF17 mainly comprised carbohydrates (87.87% ± 1.45%, w/w), along with 48.86% ± 1.2% (w/w) of soluble fibers and a low protein content (2.98% ± 0.49%, w/w). The dextran exhibited high water-holding (470.89% ± 39.67%, w/v) and oil-holding (89.945% ± 4.16%, w/v) capacities, with values close to those reported for other microbial EPS. The dextran-JF17 solutions with concentrations 0.5%, 1.0%, and 2.0% (w/v) exhibited the typical pseudoplastic non-Newtonian fluid behavior. The emulsifying capacity of dextran-JF17 was higher (26.73 ± 0.31 mL of oil/g dextran) than that of guar gum (15.45 ± 1.33 mL oil/gum). In addition, dextran-JF17 presented an emulsifying activity of approximately 65% (w/v) within 24 h, indicating a strong emulsion stabilization capacity. Collectively, these results suggested that dextran-JF17 is a good candidate for application as a viscosity, stabilizing, and emulsifying agent in the food and pharmaceutical industries. Euterpe Martius, Martius , Martius) ecosystem microorganisms LAB. . (LAB) EPS, EPS (EPS) technofunctional techno functional properties consequently applicability study technicalfunctional technical L JF JF1 physicochemical rheological waterholding, waterholding water holding, holding oilholding, oilholding oil DextranJF17 DextranJF Dextran Dextran-JF1 87.87% 8787 87 (87.87 145 1 45 1.45% w/w, ww w/w w w/w) 4886 48 86 48.86 12 2 1.2 (w/w 2.98% 298 98 (2.98 049 0 49 0.49% w/w. 470.89% 47089 470 89 (470.89 3967 39 67 39.67% w/v wv v 89.945% 89945 945 (89.945 416 4 16 4.16% capacities dextranJF17 dextranJF dextran-JF1 05 5 0.5% 10 1.0% 20 2.0 (w/v nonNewtonian non Newtonian behavior 26.73 2673 26 73 (26.7 031 31 0.3 oilg g 15.45 1545 15 (15.4 133 33 1.3 oil/gum. oilgum oil/gum oil/gum) addition 65 h Collectively viscosity stabilizing industries (LAB (EPS DextranJF1 Dextran-JF 87.87 878 8 (87.8 14 1.45 488 48.8 1. 2.98 29 9 (2.9 04 0.49 470.89 4708 47 (470.8 396 3 6 39.67 89.945 8994 94 (89.94 41 4.16 dextranJF1 dextran-JF 0.5 1.0 2. 26.7 267 7 (26. 03 0. 15.4 154 (15. 13 87.8 (87. 1.4 48. 2.9 (2. 0.4 470.8 (470. 39.6 89.94 899 (89.9 4.1 26. (26 15. (15 87. (87 (2 470. (470 39. 89.9 (89. 4. (1 (8 ( (47 89. (89 (4

RESUMO Os frutos da juçara (Euterpe edulis Martius), importante palmeira nativa do ecossistema da Mata Atlântica, exibe uma rica diversidade de microrganismos, incluindo bactérias lácticas (LAB). As LAB são altamente capazes de sintetizar exopolissacarídeos (EPS), que são biopolímeros de carboidratos extracelulares com propriedades tecnofuncionais e, consequentemente, ampla aplicabilidade. No presente estudo, informações tecnofuncionais da dextrana produzida por L. pseudomesenteroides JF17 foram obtidas através da determinação de suas propriedades físico-químicas, reológicas, de retenção de água, de retenção de óleo e emulsificantes. A dextrana-JF17 era composta principalmente por carboidratos (87,87% ± 1,45%, p/p), juntamente com 48,86% ± 1,2% (p/p) de fibras solúveis e baixo teor de proteínas (2,98% ± 0,49%, p/p). A dextrana exibiu alta capacidade de retenção de água (470,89% ± 39,67%, v/v) e de retenção de óleo (89,945% ± 4,16%, v/v), com valores próximos aos relatados para outros EPS microbianos. As soluções de dextrana-JF17 com concentrações de 0,5%, 1,0% e 2,0% (p/v) exibiram o comportamento típico de fluido pseudoplástico não newtoniano. A capacidade emulsificante da dextrana-JF17 foi superior (26,73 ± 0,31 mL de óleo/g de dextrana) à da goma guar (15,45 ± 1,33 mL de óleo/goma). Além disso, a dextrana-JF17 apresentou uma atividade emulsificante de aproximadamente 65% (p/v) em 24 horas, indicando uma forte capacidade de estabilização de emulsões. Coletivamente, esses resultados sugerem que a dextrana-JF17 é uma boa candidata para aplicação como agente viscosificante, estabilizante e emulsificante nas indústrias alimentícia e farmacêutica. Euterpe Martius, Martius , Martius) Atlântica microrganismos LAB. . (LAB) EPS, (EPS) consequentemente aplicabilidade estudo L JF JF1 físicoquímicas, físicoquímicas físico químicas, químicas físico-químicas reológicas emulsificantes dextranaJF17 dextranaJF dextrana-JF1 87,87% 8787 87 (87,87 145 1 45 1,45% p/p, pp p/p p p/p) 4886 48 86 48,86 12 2 1,2 (p/p 2,98% 298 98 (2,98 049 0 49 0,49% p/p. 470,89% 47089 470 89 (470,89 3967 39 67 39,67% v/v vv v 89,945% 89945 945 (89,945 416 4 16 4,16% v/v, microbianos 05 5 0,5% 10 1,0 20 2,0 p/v pv (p/v newtoniano 26,73 2673 26 73 (26,7 031 31 0,3 óleog g 15,45 1545 15 (15,4 133 33 1,3 óleo/goma. óleogoma óleo/goma óleo/goma) disso 65 horas emulsões Coletivamente viscosificante farmacêutica (LAB (EPS dextranaJF1 dextrana-JF 87,87 878 8 (87,8 14 1,45 488 48,8 1, 2,98 29 9 (2,9 04 0,49 470,89 4708 47 (470,8 396 3 6 39,67 89,945 8994 94 (89,94 41 4,16 0,5 2, 26,7 267 7 (26, 03 0, 15,4 154 (15, 13 87,8 (87, 1,4 48, 2,9 (2, 0,4 470,8 (470, 39,6 89,94 899 (89,9 4,1 26, (26 15, (15 87, (87 (2 470, (470 39, 89,9 (89, 4, (1 (8 ( (47 89, (89 (4

Resumen Los exopolisacáridos (EPS) pueden ser utilizados como agentes reductores confiriendo mejores propiedades físicas y químicas a las nanopartículas metálicas. Este estudio tuvo como objetivo sintetizar y evaluar las características fisicoquímicas, estructurales y funcionales de nanopartículas de ZnO producidas con EPS de Lactiplantibacillus fabifermentans BAL-27-ITTG. La caracterización estructural de los EPS exhibió una estructura de alto peso molecular compuesta principalmente de manosa y glucosa con enlaces α-1,4, α-1,3, α-1,6 de acuerdo con el espectro de RMN. El aumento de la concentración de EPS en la síntesis provoca el incremento en el tamaño de las partículas en escala micrométrica disminuyendo el índice de polidispersidad. La síntesis de las nanopartículas se confirmó mediante un barrido espectral UV-vis y el espectro FT-IR mostró picos de absorción a 600 cm-1 asociados al enlace Zn-O. Las nano (NP) y micropartículas (MP) sintetizadas mostraron actividades funcionales mejoradas respecto al EPS libre. Los valores máximos en actividad antioxidante (80.25 %), capacidad de retención de agua (3.06 g H2O/g muestra), actividad emulsionante (69.85 %) y actividad floculante (69.07 %) se obtuvieron con las MpZnO-EPS sintetizadas con 6 mg/mL del agente reductor. La actividad bacteriostática fue observada contra S. aureus y L. fabifermentans. La ausencia de hemólisis confirmó la biocompatbilidad de las partículas.

Abstract Exopolysaccharides (EPS) can be used as reducing agents and stabilizers, improving the physical and chemical properties of metallic nanoparticles. This study aimed to synthesize and evaluate the physicochemical, structural, and functional characteristics of ZnO particles obtained from EPS produced by Lactiplantibacillus fabifermentans BAL-27-ITTG. The structural characterization of the EPS exhibited a high molecular weight structure composed mainly of mannose and glucose, possibly linked by α-1-4, α-1-3, α-1-6 according to the RMN spectrum. The increase in EPS concentration during the synthesis leads to an increase of particle size at micrometric scale, decreasing the polydispersity index. The synthesis was confirmed with a UV-vis spectral scan, while the FT-IR spectrum showed absorption peaks at 600 cm-1 associated with the Zn-O bond. SSynthetized nano (NP) and microparticles (MP) showed improved functional characteristics comparing to free EPS. The highest values of antioxidant activity (80.25 %), water holding capacity (3.06 g H2O/g sample), emulsifying activity (69.85 %), and flocculant activity (69.07 %) were obtained from MpZnO-EPS synthetized with a concentration of 6 mg/mL of the reducing agent. Bacteriostatic activity was observed against S. aureus and L. fabifermentans. The absence of hemolysis confirms the biocompatibility of the particles.

Abstract Bacterial strains were isolated from soil and aqueous solution samples from the Salar del Hombre Muerto, Argentina. A total of 141 strains were characterized and the tolerance to sodium chloride was evaluated. We performed a screening to search for molecules of biotechnological interest: carotenoids (11%), emulsifiers (95%), and exopolysaccharides (6%), and to assess the production of enzymes, including proteolytic (39%), lipolytic (26%), hemolytic (50%), and catalase activities (99%); 25 bacterial strains were selected for further studies. Some of them produced biofilms, but only Bacillus sp. HA120b showed that ability in all the conditions assayed. Although 21 strains were able to form emulsions, the emulsifying index Kocuria sp. M9 and Bacillus sp. V3a cultures were greater than 50% and, emulsions were more stable when the bacteria grew in higher salt concentrations. Only pigmented Kocuria sp. M9 showed lipolytic activity on olive oil medium and was able to produce biofilms when cultured without and with 4 M of NaCl. Yellow pigments, lipase activity, and biosurfactant production were observed for Micrococcus sp. SX120. Summarizing, we found that the selected bacteria produced highly interesting molecules with diverse industrial applications and, many of them are functional in the presence of high salt concentrations. Muerto Argentina 14 evaluated interest 11%, 11 11% , (11%) 95%, 95 95% (95%) 6%, 6 6% (6%) enzymes 39%, 39 39% (39%) 26%, 26 26% (26%) 50%, 50 (50%) 99% 99 (99%) 2 studies sp HAb HA b assayed Va V concentrations NaCl pigments SX120 SX Summarizing 1 (11% 9 (95% (6% 3 (39% (26% 5 (50% (99% SX12 (11 (95 (6 (39 (26 (50 (99 SX1 (1 (9 ( (3 (2 (5

Water-insoluble exopolysaccharides (I-EPS) are a virulence factor for dental biofilms. It has already been demonstrated that mango pulp induces the secretion of glucan-hydrolytic enzymes in the fungus Trichoderma harzianum, and that they have an effect on I-EPS from young biofilms. Aim Evaluate the effect of mango peel as an enzyme inducer in T. harzianum, and the effect of enzymes secreted on mature biofilms. Methods Fractions of the peel (PL) and ethanol-precipitated pulp (PP) of Tommy Atkins mangoes were sterilized and added to a culture medium containing T. harzianum for induction of hydrolytic enzymes. After 192 h, the culture medium was centrifuged and the supernatant (enzyme extract) was used as treatment on S. mutans biofilms (n=9): a) NaCl 0.9 %; b) 0.12 % chlorhexidine digluconate; and c) extract of enzymes induced by PL or PP. Acidogenicity, bacterial viability, quantification of insoluble polysaccharides, and three-dimensional analysis of the biofilm by scanning electron microscopy (SEM) was performed. Data were analyzed by ANOVA followed by the Tukey test (α=5 %). Results The hydrolytic enzymes did not alter the metabolism or bacterial viability of the biofilm (p<0.05). Although the images obtained by SEM suggest some degree of matrix degradation, the quantification of I-EPS for the PL and PP groups did not differ from the control group (p>0.05), suggesting a slight effect on the disorganization of the mature S. mutans biofilm. Conclusion The results suggest that mango peel fraction can induce secretion of mutanase by T. harzianum, however in an insufficient amount to generate significant degradation on cariogenic biofilm. Waterinsoluble Water IEPS I EPS (I-EPS glucanhydrolytic glucan T (PL ethanolprecipitated ethanol precipitated (PP 19 h S n=9 n9 n 9 (n=9) 09 0 0. b 012 12 0.1 digluconate c Acidogenicity polysaccharides threedimensional three dimensional (SEM performed α=5 α5 α 5 (α= %. . %) p<0.05. p005 p p<0.05 05 (p<0.05) p>0.05, p>0.05 , (p>0.05) 1 n= (n=9 01 α= (α p00 p<0.0 (p<0.05 p>0.0 (p>0.05 (n= p0 p<0. (p<0.0 p>0. (p>0.0 (n p<0 (p<0. p>0 (p>0. p< (p<0 p> (p>0 (p< (p> (p

Abstract Streptococcus mutans is one of the main factors in formation of cariogenic biofilms. New strategies need to be developed to reduce the formation of cariogenic biofilms. For this purpose, bacterial exopolysaccharides (EPS) could be considered as new agents against biofilms. Therefore, cell-bound (b-EPS) and released exopolysaccharides (r-EPS) were extracted from the strains Apilactobacillus kunkeei K1.10 and Latilactobacillus curvatus Kar.9b isolated from the microbiota of honeybees, and their antibiofilm effects on S. mutans biofilm formation were determined. The highest reduction in biofilm formation was achieved by r-EPS of L. curvatus Kar.9b and A. kunkeei K1.10. Scanning electron micrographs (SEM) showed that r-EPS inhibited biofilm formation by reducing adhesion of S. mutans. To increase the production of r-EPS from A. kunkeei K1.10, the effects of different incubation conditions were also analyzed. The highest EPS production was obtained during 48 h-incubation at 37ºC in a medium containing 1% fructose. r-EPS can be used as a raw material to inhibit cariogenic biofilms. Further studies revealing the detailed structural analysis of r-EPS and the mechanism of action of its antibiofilm effect could be beneficial. Finally, b-EPS and r-EPS from lactic acid bacteria were found to have very different properties in terms of their antibiofilm properties. biofilms purpose (EPS Therefore cellbound cell bound bEPS b (b-EPS rEPS r (r-EPS K110 K K1 10 K1.1 Kar9b Karb Kar 9b honeybees S determined L A SEM (SEM analyzed 4 hincubation h ºC 1 fructose beneficial Finally K11 K1.

Resumen: Las tecnologías “ómicas” son herramientas novedosas que facilitan el estudio de las comunidades microbianas de distintos ecosistemas, particularmente de la costra biológica del suelo, también llamada biocostra. Entre estas tecnologías se encuentran la genómica, transcriptómica, proteómica, metabolómica y metagenómica, que son utilizadas para analizar la diversidad y las funciones que llevan a cabo los microorganismos a través del estudio de sus biomoléculas y vías metabólicas. Entre los microorganismos que habitan la biocostra destacan las cianobacterias, las cuales son un grupo de bacterias fototróficas encargadas de realizar procesos importantes en el suelo, tal como la fijación de nitrógeno atmosférico, carbono orgánico, síntesis de clorofila y ficobilinas, así como la producción de exopolisacáridos para mejorar la estabilidad y fertilidad del suelo. Por lo tanto, el objetivo de la presente revisión es el de explorar la diversidad y la función que desempeñan estas comunidades microbianas en la biocostra, particularmente las cianobacterias, destacando los estudios realizados mediante el uso de las tecnologías ómicas. El conocimiento generado en los últimos años a través de las tecnologías ómicas ha demostrado la limitada cobertura que presentan las técnicas moleculares tradicionales, resultando en una subestimación de la diversidad real de las comunidades microbianas. Además, se ha mejorado la comprensión de los procesos ecológicos desarrollados por los microorganismos en beneficio de la biocostra, así como las capacidades funcionales individuales y colectivas, las cuales servirán como línea base para proponer estrategias importantes que solucionen la problemática de la degradación de los suelos.

Summary: The "omics" technologies are novel tools that facilitate the study of microbial communities in different ecosystems, particularly the biological soil crust, also called biocrust. These technologies include genomics, transcriptomics, proteomics, metabolomics, and metagenomics, which are used to analyze the diversity and functions carried out by microorganisms through the study of their biomolecules and metabolic pathways. Among the microorganisms that inhabit the biocrust are the cyanobacteria, which are a group of phototrophic bacteria responsible for important processes in the soil, such as the fixation of atmospheric nitrogen, organic carbon, chlorophyll and phycobilin synthesis, as well as the production of exopolysaccharides to improve soil stability and fertility. Therefore, the objective of this review is to explore the diversity and role that these microbial communities play in the biocrust, particularly cyanobacteria, highlighting studies conducted using omics technologies. The knowledge generated in recent years through omics technologies has demonstrated the limited coverage of traditional molecular techniques, resulting in an underestimation of the real diversity of microbial communities. In addition, there has been an improvement in the understanding of the ecological processes developed by the microorganisms for the benefit of the biocrust, as well as the individual and collective functional capacities, which will serve as a baseline to propose important strategies to solve the problem of soil degradation.

RESUMEN Se realizó una caracterización físico-química de los efluentes procedentes de industrias del sector educación, metalmecánico, lácteos y confitería de la ciudad de Manizales, Caldas; posteriormente se obtuvieron aislamientos, en medios diferenciales suplementados, de bacterias con potencial para la producción de biopolímeros a los cuales se les aplicó pruebas para la caracterización morfológica, bioquímica y molecular. Los parámetros físico químicos obtenidos de los efluentes industriales demuestran diferencias entre ellos, ya que cada industria genera diferentes residuos aportando una determinada contaminación al efluente, se obtuvieron 73 aislamientos productores de exopolisacáridos (EPS) y 101 productores de polihidroxialcanoatos (PHA), con características morfológicas y bioquímicas variables. El estudio muestra que los efluentes industriales son una gran fuente de bacterias de interés para la producción de diversos polímeros microbianos; principalmente aquellos que producen polímeros tipo biopoliésteres intracelulares como PHA, debido a su variabilidad físico-química y nutricional permitiendo que los microorganismos se adapten a diversas características medioambientales y de composición.

ABSTRACT A physical-chemical characterization of effluents from industries in the education, metal-mechanic, dairy and confectionery sectors of the city of Manizales, Caldas; Later isolates were obtained, in differential media supplemented, from bacteria with potential for the production of biopolymers to which they were applied tests for morphological, biochemical and molecular characterization. The physical chemical parameters obtained from the industrial effluents show a difference between them, since each industry generates different waste contributing a certain contamination to the effluent, 73 isolates producing exopolysaccharides (EPS) and 101 producers of polyhydroxyalkanoates (PHA) were obtained, with morphological characteristics and variable biochemistry. The study shows that industrial effluents are a great source of bacteria of interest for the production of various microbial polymers; mainly those that produce polymers like intracellular biopolyesters such as PHA, due to their physical-chemical and nutritional variability allowing the microorganisms to adapt to diverse environmental and compositional characteristics.

Los biofertilizantes constituidos por bacterias promotoras del crecimiento vegetal son una alternativa sustentable para estimular el crecimiento e incrementar los rendimientos del cultivo de la caña de azúcar. El objetivo de este trabajo fue aislar y caracterizar una cepa endofítica del género Gluconacetobacter capaz de colonizar y promover el crecimiento del cultivo, y que presente además alta viabilidad y estabilidad en medios de cultivo de bajo costo para su propagación a escala piloto e industrial. A partir de tallos de caña de azúcar, se aisló la cepa endofítica OCG1 de Gluconacetobacter con capacidad potencial para fijar nitrógeno. Luego de inocular yemas aisladas de caña de azúcar de la variedad TUC 95-10, se observó que el aislamiento OCG1 fue capaz de colonizar el sistema radicular de las plántulas e incrementar el peso fresco y seco tanto del sistema aéreo como del radicular. Finalmente, OCG1 presentó capacidad para generar gran cantidad de biomasa y para producir y excretar exopolisacáridos (EPS) en el medio de cultivo industrial utilizado para su propagación a escala piloto. Además, conservó su viabilidad durante el almacenamiento prolongado a temperatura ambiente (25°C). De esta forma, la cepa Gluconacetobacter OCG1 podría emplearse en la formulación de un biofertilizante para obtener plantines de caña de azúcar con alto valor agregado a partir de la inoculación de las yemas aisladas.

Biofertilizers constituted by plant growth promoting bacteria, are a sustainable alternative to stimulate sugarcane growth and development. The objective of this work was to isolate and characterize an endophytic Gluconacetobacter strain capable of colonizing and promoting crop growth. It also has a high viability and stability in low cost culture medium for its pilot and industrial scale propagation. From sugarcane stems, the endophytic strain Gluconacetobacter OCG1 with potential ability to fix nitrogen was isolated. After TUC 95- 10 sugarcane buds inoculation, it was observed that OCG1 strain was able to colonize root system and to increase fresh and dry weight of both vegetative and root systems. Finally, OCG1 strain showed high ability to generate large amount of biomass and to produce and excrete exopolysaccharides (EPS) in the industrial culture medium used for the propagation at pilot scale. Also, it retained its viability during long storage at room temperature (25°C). Hence, Gluconacetobacter OCG1 strain could be used as a biofertilizer to obtain high added value sugar cane seedlings from the inoculation of isolated buds.

Abstract This study assessed the inhibitory potential of the probiotics Lactobacillus (LB) exopolysaccharides (EPS) with or without extracts of Satureja calamintha on enteropathogenic Escherichia coli (EPEc) responsible for gastroenteritis. Methanolic and hydromethanolic extracts were prepared by cold maceration and subjected to phytochemical screening. The compounds of the extracts were determined with the colorimetric assays and identified using high-performance liquid chromatography coupled with diode array detector (HPLC-DAD). Antioxidant activities of the extracts were also evaluated by using 2,2-diphenyl-1-picrylhydrazil (DPPH) radical scavenging. Antibacterial effect on EPEc was evaluated by using both agar disc diffusion and microdilution methods. The in vitro test of auto-aggregation was investigated. Microbiological analysis showed that 63% of the isolated LB were producing EPS, with the amount ranging from 8.21 to 43.13 mg/L. Chemical analysis of the extracts revealed the presence of polyphenols and flavonoids, more abundant in the hydromethanolic extract, which presented the highest content with 2.11 mg EGA/g of polyphenol and 1.64 mg EC/g of flavonoids and 1.71 mg EGA/g of polyphenol and 1.15 mg EC/g of flavonoids in the methanolic extract. Hydromethanolic extracts and EPS exhibited a more important activity than did the methanolic extract against EPEc. The combined action of EPS and extracts reduced the aggregation ability of EPEc and decreased the rate of their adhesion.

Abstract Exopolysaccharides (EPS) produced by Klebsiella oxytoca are of environmental, pharmaceutical, and medicinal interest. However, studies about the anti-inflammatory activity of EPS produced by this microorganism still remain limited. The aim of this study was to produce, characterize, and evaluate the anti-inflammatory activity of EPS from K. oxytoca in a pleurisy model. Colorimetric analysis revealed that precipitated crude exopolysaccharides (KEPSC) and deproteinated exopolysaccharides (KEPS) present high levels of total carbohydrates (65.57% and 62.82%, respectively). Analyses of uronic acid (7.90% in KEPSC and 6.21% in KEPS) and pyruvic acid (3.01% in KEPSC and 1.68% in KEPS) confirm that the EPS are acidic. Gas chromatography-mass spectrometry analyses demonstrated that the EPS consisted of rhamnose (29.83%), glucose (11.21%), galactose (52.45%), and mannose (6.50%). The treatment of an experimental pleurisy model in rats through subcutaneous administration of 50, 100, 200, and 400 mg/kg of KEPS decreased both the volume of inflammatory exudate and the number of leukocytes recruited to the pleural cavity. The present data showed that EPS production by K. oxytoca using the method described is easy to perform and results in a good yield. In addition, we show that KEPS exhibit anti-inflammatory activity when administered subcutaneously in rats.

Abstract The effect of volumetric oxygen mass transfer coefficient (KLa) on the biomass and the commercial interest biomolecules production, was studied in the Ganoderma lucidum submerged culture using a low-cost complex medium. The batch culture was carried out in a 14 L stirred tank bioreactor, a KLa initial value set at 5.3 h-1 had a positive effect on exopolysaccharides production, achieving a maximum concentration of 1.15 g/L, under this condition, biomass production was negatively affected. An increase in the KLa initial values between 17.3 32.8 h-1, allowed us to obtain a culture with better oxygen and nutrients transfer conditions. These values improved the kinetic carbohydrate uptake, fungal growth, and enabled the adequate supply of oxygen for a long time, achieving a maximum biomass concentration of 9.8 g/L. Under these conditions, the average production of exopolysaccharides is 0.46 g/L, and crude protein extract production was around 0.3 g/L. The complex medium (made from barley flour) used in this study is a low-cost medium that showed great potential for the replacement of synthetic high-cost media that are conventionally used in Ganoderma lucidum submerged cultures in a stirred tank bioreactor.

Abstract In this study, the exopolysaccharides (EPSs)-producing L. plantarum YW11 was initially evaluated for its tolerance to simulated artificial gastric juice and bile salts, and cell surface hydrophobicity. Subsequent study using a HT-29 tumor-burdened nude mouse model showed that the EPS had potent immunomodulatory and antitumor activities. Administration of the EPS had no influence on body weight of the mice, and it could significantly prevent HT-29 tumor cells induced acute liver and kidney damages. The purified EPS at a dose of 5 mg/mL was able to enhance effectively the killing activities of splenic natural killer cells and cytotoxic T lymphocyte, and to stimulate the secretion of serum cytokines IL-2 and TNF-α. As evidenced by a cell culture assay, the EPS exhibited obvious inhibition on growth of colon cancer HT-29 cells treated with 600 μg/mL of the EPS for 72 h with an inhibition rate of 58.02%. Administration of the EPS obviously inhibited growth of HT-29 xenograft tumor to an extent near that of the positive control (5-Fu, 25 mg/kg bw). Therefore, the results of this study indicated the important roles of the EPS in the potential probiotic functions of the strain.

Resumo O objetivo deste trabalho foi investigar a presença de fatores de virulência, resistência a antimicrobianos e metais pesados em 97 enterococos isolados de alimentos de origem animal. Foram realizadas provas fenotípicas e genotípicas para a identificação no nível de espécie dos enterococos recuperados. Foram identificados 67 isolados como Enterococcus faecium, 9 de Enterococcus faecalis, 3 de Enterococcus durans, 2 como Enterococcus hirae e 1 como Enterococcus raffinosus. Em 15 isolados, sua confirmação em nível de espécie não foi alcançada por métodos fenotípicos e/ou genotípicos. A produção de exopolissacarídeos foi o fator de virulência mais frequente e se detectou em 46 enterococos, enquanto que 19 apresentaram atividade de gelatinase e somente um apresentou beta-hemólise. O estudo da concentração inibitória mínima (CIM) revelou que 29 isolados eram resistentes à vancomicina (≥32 μg/mL), e 26 deles foram também resistentes a teicoplanina (≥32 μg/mL). Pelo contrário, da quantidade total de isolamentos, somente 21 apresentaram resistência à tetraciclina (≥16 μg/mL) e apenas 3 cepas apresentaram resistência à ampicilina (≥16 μg/mL). A prova em ágar revelou que 90 cepas eram resistentes ao zinco (≥12 mM), enquanto que todas mostraram resistência intermediária ao cobre (4-12 mM). Os alimentos de origem animal atuam como reservatórios de cepas de Enterococcus spp. os quais expressam fatores de virulência, e resistência aos antimicrobianos e a metais pesados. A implementação de uma vigilância contínua em enterococos isolados de alimentos de origem animal é essencial para a saúde dos humanos.

Abstract This study was aimed at investigating the presence of virulence factors, antimicrobial and heavy metals resistance in 97 isolated enterococci from food of animal origin. Phenotypic and genotypic tests for species-level identification of the recovered isolates were carried out. This resulted in the iden tification of 67 strains as Enterococcus faecium, 9 as Enterococcus faecalis, 3 as Enterococcus durans, 2 as Enterococcus hirae and 1 as Enterococcus raffinosus. In 15 isolates, their confirmation at species level was neither achieved by phenotypic nor by genotypic methods. Exopolysaccharides production was the most frequent virulence factor and was detected in 46 isolates, while 19 displayed gelatinase activity, and only one resulted beta-hemolytic. Minimum inhibitory concentration (MIC) study revealed that 29 isolates were vancomycin-resistant (≥32 μg/mL), 26 of them were also resistant to teicoplanin (≥32 μg/mL). On the other hand, of the total isolates, 21 exhibited resistance to tetracycline (≥16 μg/mL) and only 3 enterococci exhibited resistance to ampicillin (≥16 μg/mL). Agar plates test revealed that 90 strains were resistant to zinc (≥12 mM) while all exhibited intermediate copper resistance (4-12 mM). Foods of animal origin act as a reservoir of Enterococcus spp. strains, expressing virulence factors, and resistance to antimicrobials and heavy metals. Therefore, the implementation of continuous surveillance in enterococci isolated from food of animal origin is essential to human health.

Resumen Este trabajo tuvo como objetivo investigar la presencia de factores de virulencia, resistencia a antimicrobianos y metales pesados en 97 enterococos aislados de alimentos de origen animal. Se realizaron pruebas fenotípicas y genotípicas para la identificación a nivel de especie de los enterococos recuperados. Se identificaron 67 aislados como Enterococcus faecium, 9 como Enterococcus faecalis, 3 como Enterococcus durans, 2 como Enterococcus hirae y 1 como Enterococcus raffinosus. En 15 aislados no se logró su confirmación a nivel de especie por métodos fenotípicos ni genotípicos. La producción de exopolisacáridos fue el factor de virulencia más frecuente y se detectó en 46 enterococos, mientras que 19 exhibieron actividad gelatinasa y solo uno presentó beta-hemólisis. El estudio de la concentración inhibitoria mínima (CIM) reveló que 29 aislados resultaron resistentes a vancomicina (≥32 μg/mL) y 26 de ellos también eran resistentes a teicoplanina (≥32 μg/mL). Del total de aislamientos, 21 presentaron resistencia a tetraciclina (≥16 μg/mL) y sólo 3 exhibieron resistencia a la ampicilina (≥16 μg/mL). La prueba en agar reveló que 90 cepas resultaron resistentes al zinc (≥12 mM) mientras que todas exhibieron resistencia intermedia al cobre (4-12 mM). Los alimentos de origen animal actúan como reservorios de cepas de Enterococcus spp. que expresan factores de virulencia y resistencia a los antimicrobianos y a metales pesados. La implementación de una vigilancia continua en enterococos aislados de alimentos de origen animal es esencial para la salud humana.

Abstract Biocorrosion is the main process that causes pipeline damages and losses in the oil industry. The objective of this work was to investigate the influence of biofilm forming microorganisms on the biocorrosion of X80 steel exposed in produced water through microbiological characterization, film and biofilm analysis by optical microscopy and scanning electron microscopy, weight loss and surface analysis by laser confocal microscopy. Changes in produced water after 360 days were attributed to planktonic cells, temperature conditions, contact with air, photo-oxidation, biodegradation, and seasonality. The total aerobic bacteria presented sessile cell concentration of 7.39 x 104 CFU/cm2, while the other investigated groups showed lower concentrations. The micrography of the film showed salt crystals, whereas in the biofilm microorganisms, exopolysaccharides and corrosion products were observed. Weight loss after 360 days for the abiotic and biotic systems was 0.0222 g/cm2 and 0.3039 g/cm2, respectively, showing that microorganisms accentuated the corrosion of X80 steel.