Graciela Garrote

Fil: Fait, Maria Elisa. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biologicas. Laboratorio de Investigacion de Proteinas Vegetales; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina

La gastritis constituye un importante problema de salud a nivel mundial que puede derivar a complicaciones severas como úlceras y cáncer. Actualmente, el tratamiento de las úlceras gástricas (inhibidores de la bomba de protones y antibióticos) está asociado a diversos efectos adversos tales como diarrea y nauseas. En este contexto, el uso de leches fermentadas con microorganismos probióticos surge como una posible alternativa para prevenir y aliviar los síntomas asociados a la inflamación gástrica. El objetivo del presente trabajo fue evaluar la cepa Lactobacillus paracasei CIDCA 8339 aislada de kefir y su leche fermentada en cuanto a su capacidad antiinflamatoria y protectora de la mucosa gástrica.L. paracasei CIDCA 8339, productor de exopolisacárido (EPS), se creció en caldo MRS (24h, 30ºC). Se evaluó su capacidad de adhesión a células de epitelio gástrico AGS. A partir de la leche fermentada con la cepa (5%v/v, 24h a 30ºC) se obtuvo la fracción no microbiana (FNM) (centrifugación 5min a 6000rpm, filtración 0,45µm y neutralización con NaOH) y se evaluó la capacidad moduladora de la respuesta inmune innata inducida con flagelina (0,5 µg/ml) en células AGS mediante determinación de IL-8 por ELISA. En el mismo sistema se estudió el efecto de los metabolitos presentes en la FNM incluyendo EPS (200 y 800mg/L), lactato y acetato. Se estudió la modulación de la vía NF-κB mediante transfección transiente de las células AGS con el gen reportero luciferasa de luciérnaga bajo el dominio de un promotor inducible con NF-κB. Para evaluar el efecto gastroprotector en ratones Balb-c, se administró ad libitum durante tres días una suspensión de L. paracasei CIDCA 8339 (2.109 UFC/ml). Luego, se les administró por gavage 200µl de etanol 60% + 0,15M HCl para inducir la gastritis y al cabo de 2hs se sacrificaron y se evaluó el daño gástrico en cortes histológicos teñidos con hematoxilina y eosina.L. paracasei CIDCA 8339 fue capaz de adherirse a células AGS (106 de 108 UFC/ml iniciales). La FNM de la leche fermentada redujo la expresión de IL-8 en un 70%, similar a lo observado con el sobrenadante de una leche acidificada conteniendo lactato 100mM y acetato 12mM. Las soluciones acuosas de lactato y acetato modularon la expresión de IL-8 de manera dosis dependiente, la cual no se observó con el EPS. La presencia de la FNM y lactato 100mM en células transfectadas redujo la expresión de la luciferasa indicando inhibición de la vía NF-κB. El consumo de L. paracasei CIDCA 8339 en ratones logró reducir el daño inducido a nivel gástrico en comparación con el grupo control (agua).La leche fermentada con L. paracasei CIDCA 8339 presentó buenas propiedades antiinflamatorias y protectoras a nivel gástrico que pueden ser atribuidas en parte a la bacteria y en parte al ácido láctico producido in situ en el estómago o durante la fermentación de la leche, siendo una alternativa para reducir el daño y aliviar la sintomatología en pacientes que sufren gastritis.Fil: Bengoa, Ana Agustina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Errea, Agustina Juliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; ArgentinaFil: Rumbo, Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; ArgentinaFil: Abraham, Analia Graciela. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas. Área de Bioquímica y Control de Alimentos; ArgentinaFil: Garrote, Graciela Liliana. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentin

Cette invention concerne des produits fermentes a base de permeat de lactoserum, des procedes de production et leurs utilisations. L’invention concerne plus specifiquement des produits fermentes contenant au moins entre 4,75 x 10 8 et 2,14 x 10 9 UFC/ml de bacteries lactiques et entre 8,50 x 10 5 et 1,55 x 10 7 UFC/ml de levure de kefir. Le produit a un pH compris entre 4 et 5 et peut exister sous forme liquide, lyophilisee ou dessechee en pulverisation. Le produit est obtenu par fermentation de permeat de lactoserum avec des grains de kefir et/ou un concentre de culture de grains de kefir. Le produit fermente peut exister sous forme liquide, lyophilisee ou de poudre seche et peut etre utilise dans la nourriture des animaux ou de l’homme.

Among artisanal fermented beverages, kefir (fermented milk drink) and water kefir (fermented nondairy beverage) are of special interest because their grains can be considered natural reservoirs of safe and potentially probiotic strains. In the last years, several reports on Lacticaseibacillus paracasei (formerly Lactobacillus paracasei) isolated from both artisanal fermented beverages were published focusing on their health-promoting properties. Although this is not the predominant species in kefir or water kefir, it may contribute to the health benefits associated to the consumption of the fermented beverage. Since the classification of L. paracasei has been a difficult task, the selection of an adequate method for identification, which is essential to avoid mislabeling in products, publications, and some publicly available DNA sequences, is discussed in the present work. The last findings in health promoting properties of L. paracasei and the bioactive compounds are described and ...

1.Agroindustrial by-products and residues can be transformed into valuable compounds in biorefineries. Here we present a new concept: production of fuel ethanol, whey protein and probiotic yeast from cheese whey. An initial screening under industrially relevant conditions, involving thirty Kluyveromyces marxianus strains, was carried out using spot assays to evaluate their capacity to grow on cheese whey or on whey permeate (100 g lactose/L), under aerobic or anaerobic conditions, in the absence or presence of 5% ethanol, at pH 5.8 or pH 2.5. The four best growing K. marxianus strains were selected and further evaluated in a miniaturized industrial fermentation process using reconstituted whey permeate (100 g lactose/L) with cell recycling (involving sulfuric acid treatment). After five consecutive fermentation cycles, the ethanol yield on sugar reached 90% of the theoretical maximum in the best cases, with 90% cell viability. Cells harvested at this point displayed probiotic proper...

Kefir is a fermented milk obtained by the activity of kefir grains which are composed of lactic and acetic acid bacteria, and yeasts. Many beneficial health effects have been associated with kefir consumption such as stimulation of the immune system and inhibition of pathogenic microorganisms. The biological activity of kefir may be attributed to the presence of a complex microbiota as well as the microbial metabolites that are released during fermentation. The aim of this work was to characterise the non-microbial fraction of kefir and to study its antagonism againstEscherichia coli,Salmonellaspp. andBacillus cereus.During milk fermentation there was a production of organic acids, mainly lactic and acetic acid, with a consequent decrease in pH and lactose content. The non-microbial fraction of kefir added to nutrient broth at concentrations above 75% v/v induced a complete inhibition of pathogenic growth that could be ascribed to the presence of un-dissociated lactic acid. In vitro...

Kefir is a traditional fermented milk originating many centuries ago in the Caucasian mountains. It is produced by fermentative activity of ‘kefir grains’ consisting mainly of lactococci, lactobacilli and yeasts in a protein–polysaccharide matrix. The grains contain a relatively stable and specific balance of microorganisms which exist in a complex symbiotic relationship. The grains grow in the process of kefir making only from pre-existing grains (Saloff-Coste, 1996). When kefir grains are allowed to grow in milk, microorganisms are shed from the grains into milk where they continue to multiply with the production of acid, flavour and physicochemical changes.The traditional method of kefir making is currently by adding kefir grains directly as starter to milk that has been pasteurized and cooled to 20–25°C. After a period of fermentation lasting ∼24 h, the grains are removed by filtration and the beverage is ready for consumption (Saloff-Coste, 1996). Kefir from which the grains ha...

We report here a comparative analysis of the growth, acidification capacity, and chemical and microbiologic composition between kefir grains after 20 subcultures in whey at 20, 30, and 37°C and the original kefir grains coming from milk along with a determination of the microbiological composition of the fermented whey as compared with that of traditional fermented milk.When fermentation was carried out repeatedly at 30 or 37°C, kefir grains changed their kefir-like appearance, exhibited reduced growth rates, had a lower diversity of yeasts and water content, and a higher protein-to-polysaccharide ratio compared with the original kefir grains. In contrast, at 20°C kefir grains could remain in whey for prolonged periods without altering their acidification capacity, growth rate, macroscopic appearance or chemical and microbiologic composition—with the only difference being a reduction in certain yeast populations after 20 subcultures in whey. At this incubation temperature, the prese...

Currently, the growing demand for non-dairy functional foods leads to the constant development of new products. The objective of the present work was to obtain a soy-based fermented beverage employing the strains Lactiplantibacillus plantarum CIDCA 8327 or Lacticaseibacillus paracasei BGP1 and to analyze the effect of post-fermentation addition of inulin on the bacterial resistance. Also, the antimicrobial and antioxidant activity of the fermented soy-based beverages were analyzed. The soy-based matrix was shown to be a suitable substrate for the growth of both lactic acid bacteria, and the fermented beverages obtained presented bioactive properties such us antioxidant activity and bactericidal effect against pathogen microorganisms. The addition of inulin after the fermentation process avoid the hydrolysis and so, preserve its polymerization degree and thus the potential prebiotic effect. The soy-based fermented beverages containing inulin showed higher bacterial viability during r...

Introduction: the confinement imposed to reduce the spread of COVID-19 induces changes in habits and unhealthy lifestyles. Objectives: to verify changes associated with confinement in eating habits and lifestyle in the Argentine population and their differences between the metropolitan area of Buenos Aires (AMBA) and the rest of the country. Materials and methods: cross-sectional, descriptive, and analytical study, through an “online” survey (December 2020) carried out on adults residing in Argentina. Age, gender and place of residence were surveyed, as well as the changes registered regarding weight, eating habits, physical activity, desire to eat and quality of sleep. A descriptive analysis of the valid surveys received (N=1,536) was carried out, verifying differences between the regions using parametric and nonparametric tests, considering significant p<0.05. Results: 75.1% of the participants were women (38.8±13.1 years), 60.5% from the AMBA and 39.5% from the rest of the cou...

Fil: Londero, Alejandra. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico la Plata. Centro de Investigaciones en Criotecnologia de Alimentos (i); Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina

Gastrointestinal conditions along the digestive tract are the main stress to which probiotics administrated orally are exposed because they must survive these adverse conditions and arrive alive to the intestine. Adhesion to epithelium has been considered one of the key criteria for the characterization of probiotics because it extends their residence time in the intestine and as a consequence, can influence the health of the host by modifying the local microbiota or modulating the immune response. Nevertheless, there are very few reports on the adhesion properties to epithelium and mucus of microorganisms after passing through the gastrointestinal tract. In the present work, we evaluate the adhesion ability in vitro of L. paracasei strains isolated from kefir grains after acid and bile stress and we observed that they survive simulated gastrointestinal passage in different levels depending on the strain. L. paracasei CIDCA 8339, 83120 and 83123 were more resistant than L. paracasei...

Milk and MRS broth fermented with kefir grains from different households were examined for inhibitory activity toward gram-negative and gram-positive strains. Fermented milk obtained with 10 g per 100 ml of inoculum (final pH 3.32 to 4.25) and MRS broth fermented with 1 and 10 g per 100 ml of inocula (final pH 4.18 to 5.25) had inhibitory power demonstrated by spot test and agar well diffusion assay. This inhibitory effect could be assigned to the undissociated form of lactic and acetic acid produced during the fermentation process. Kefir supernatants inhibited the growth of Escherichia coli 3 in nutrient broth at 37°C for 24 h. However, supernatants of yogurt or milk artificially acidified with lactic and acetic acids allowed the growth of E. coli 3 in the same conditions. A bacteriostatic effect of milk fermented with kefir grains over E. coli 3 was also demonstrated.

Two novel arginine-based cationic surfactants were synthesized using as biocatalyst papain, an endopeptidase from Carica papaya latex, adsorbed onto polyamide. The classical substrate N (α)-benzoyl-arginine ethyl ester hydrochloride for the determination of cysteine and serine proteases activity was used as the arginine donor, whereas decyl- and dodecylamine were used as nucleophiles for the condensation reaction. Yields higher than 90 and 80 % were achieved for the synthesis of N (α)-benzoyl-arginine decyl amide (Bz-Arg-NHC10) and N (α)-benzoyl-arginine dodecyl amide (Bz-Arg-NHC12), respectively. The purification process was developed in order to make it more sustainable, by using water and ethanol as the main separation solvents in a single cationic exchange chromatographic separation step. Bz-Arg-NHC10 and Bz-Arg-NHC12 proved antimicrobial activity against both Gram-positive and Gram-negative bacteria, revealing their potential use as effective disinfectants as they reduced 99 % ...

ABSTRACT The antagonistic effect against Salmonella spp. and the immunomodulatory capacity of whey fermented with kefir grains and with three strains isolated from them – Lactobacillus plantarum CIDCA 8327, Lactobacillus kefiri CIDCA 8348 and Kluyveromyces marxianus var. marxianus CIDCA 8154 – were evaluated. Both fermented products interfered with the capacity of Salmonella spp. to associate and invade Caco-2/TC7 cells and reduced up to the basal level the expression of the CCL20 in response to a pro-inflammatory stimulus on Caco-2 CCL20:luc cells. The products with potential application as probiotics obtained by fermentation of whey with kefir micro-organisms represent an alternative to increase whey economic value.

ABSTRACT This chapter discusses the surface characterization and adhesive properties of Bifidobacteria. The colonization of different portions of the intestinal tract by beneficial microorganisms constitutes the first defensive barrier against the invasion of pathogenic microorganisms or toxic substances. The ability to adhere to the intestinal epithelia and to compete with other microorganisms seems to be crucial for a probiotic strain to colonize the gastrointestinal tract. Bacteria of the genus Bifidobacterium are normal inhabitants of the gut of humans and animals, where they play an important role in the prevention of gastrointestinal disorders. Bifidobacteria have been successfully employed to prevent antibioticrelated diarrhea and acute infant diarrhea. One approach to obtaining information regarding adherent behavior in the intestinal ecosystem is to study the surface properties of the selected strains. The adhesion of microorganisms to natural environments can be inferred by studying the surface properties of bacteria, employing a combination of methodologies. This procedure includes several determinations such as partitioning of bacteria in hydrocarbon-aqueous interfaces, ζ potential, binding to solid surfaces, capacity to aggregate particles, and adhesion to monolayers of cell cultures. These methodologies are applied to a collection of bifidobacteria isolated at CIDCA (Centro de Investigación y Desarrollo en Criotecnología de Alimentos, La Plata, Argentina) and to reference strains.

... Whole protein profile of kefir grain grown in milk and in soy milk during a long ... kefiranofaciens in kefir grain is an alterna-tive method for optimizing metabolite production ... produces a bacteriocin, designated lacticin 3147, which displays the advantage of acidifying milk at sufficient ...

The microflora of kefir grains of household origin was isolated and identified. At least two lactococci, two lactobacilli, two yeast and one mould were detected.Different methods for kefir grain preservation were studied. Metabolic activity of grains preserved frozen at −20 °C and −80 °C and grains stored at 4 °C was evaluated.Grains stored at −20 °C and −80 °C maintained

Fungal contamination of poultry feed causes economic losses to industry and represents a potential risk to animal health. The aim of the present study was to analyze the effectiveness of whey fermented with kefir grains as additive to reduce fungal incidence, thus improving feed safety. Whey fermented for 24 h at 20 °C with kefir grains (100 g L(-1) ) reduced conidial germination of Aspergillus flavus, Aspergillus parasiticus, Aspergillus terreus, Aspergillus fumigatus, Penicillium crustosum, Trichoderma longibrachiatum and Rhizopus sp. Poultry feed supplemented with fermented whey (1 L kg(-1) ) was two to four times more resistant to fungal contamination than control feed depending on the fungal species. Additionally, it contained kefir microorganisms at levels of 1 × 10(8) colony-forming units (CFU) kg(-1) of lactic acid bacteria and 6 × 10(7) CFU kg(-1) of yeasts even after 30 days of storage. Fermented whey added to poultry feed acted as a biopreservative, improving its resistance to fungal contamination and increasing its shelf life.

We investigated the chemical and microbiological compositions of three types of whey to be used for kefir fermentation as well as the inhibitory capacity of their subsequent fermentation products against 100 Salmonella sp. and 100 Escherichia coli pathogenic isolates. All the wheys after fermentation with 10% (wt/vol) kefir grains showed inhibition against all 200 isolates. The content of lactic acid bacteria in fermented whey ranged from 1.04 × 107 to 1.17 × 107 CFU/ml and the level of yeasts from 2.05 × 106 to 4.23 × 106 CFU/ml. The main changes in the chemical composition during fermentation were a decrease in lactose content by 41 to 48% along with a corresponding lactic acid production to a final level of 0.84 to 1.20% of the total reaction products. The MIC was a 30% dilution of the fermentation products for most of the isolates, while the MBC varied between 40 and 70%, depending on the isolate. The pathogenic isolates Salmonella enterica serovar Enteritidis 2713 and E. coli 2...

Considering that several health promoting properties are associated with kefir consumption and a reliable probiotic product requires a complete identification of the bacterial species, the present work evaluates several proved markers of probiotic potential of eleven isolates of homofermentative lactobacilli isolated from kefir grains and molecular identification and genotypic diversity. Using restriction analysis of amplified ribosomal DNA (ARDRA) and analysis of the 16S–23S rRNA internal spacer region we confirmed that all homofermentative lactobacilli belong to the speciesLactobacillus plantarum. RAPD-PCR analysis allowed the discrimination of lactobacilli in five clusters. All isolates exhibited high resistance to bile salt. High survival after one hour of exposure to pH 2·5 was observed inLb. plantarumCIDCA 8313, 83210, 8327 and 8338. All isolates were hydrophilic and non autoaggregative. Isolate CIDCA 8337 showed the highest percentage of adhesion among strains. All tested lac...

In the present study we report for the first time the presence of S-layer proteins in Lactobacillus kefir and Lactobacillus parakefir isolated from kefir grains. Soluble whole-cell protein profile obtained either by mechanical disruption (X-press) or by a combined treatment with lysozyme and SDS on whole cells, showed a significant band of apparent molecular mass of 66–71 kDa as measured by SDS–PAGE. The intensity of this band was considerably reduced when cells were treated with 5 M-LiCl. The above mentioned proteins were recovered in the LiCl extracts. After dialysis and concentration, the proteins extracted were able to reassemble in a regular array. Negative staining of these protein preparations were analysed by transmission electron microscopy and a paracrystalline arrangement was seen. Thin sections of bacteria analysed by transmission electron micrographs showed an outermost layer over the bacterial cell wall, that was lost after the LiCl treatment. The production of this su...

Several microbial interactions involving yeast and lactobacilli have been suggested in fermented products. Co-aggregation between Lactobacillus kefir and yeast Saccharomyces lipolytica isolated from kefir grains was studied by scanning electron microscopy and aggregation assays. Six out of twenty Lb. kefir strains were able to co-aggregate with Sacch. lipolytica CIDCA 812 and showed thermolabile non-covalently bound surface molecules involved in this interaction. Co-aggregation inhibition after Lb. kefir pre-treatment with 5 m-LiCl or 20 g SDS/l showed that bacterial S-layer proteins play an important role in this interaction. Presence of different sugar (mannose, sucrose and fructose) or yeast pre-treatment with sodium periodate inhibited co-aggregation between Lb. kefir and Sacch. lipolytica. Co-aggregating Lb. kefir strains were also able to agglutinate with human red blood cells and they lost this ability after treatment with 5 m-LiCl. These results and the capacity of purified ...