scholarly journals ISOLATION AND CHARACTERIZATION OF POTENTIAL PROBIOTIC YEASTS FROM DIFFERENT SOURCES

Author(s):  
Nilanjana Das ◽  
Mangala Lakshmi Ragavan

objective The main objective of the present study is to isolate yeasts from different environmental sources to investigate their potential probiotic characteristics.Methods Appropriate in vitro assays has been conducted to examine their probiotic potentiality, such as acid and bile salt tolerance, temperature resistance, stimulated GIT tolerance, cell adhesion and cholesterol removal. All the yeast isolates were tested under in vitro conditions.Results In the present study, 20 yeast species have been isolated from different sources, screened and their desirable probiotic properties viz. pH tolerance, bile salt tolerance and thermo-tolerance have been evaluated. Screened yeast isolates treated with gastric juices showed increased survival rate above 60%. A further in vitro study investigates cholesterol removal and it showed increased cholesterol removal rate up to 92%. Exopolysaccharide production was estimated for selected yeast isolates and applications are under investigation.Conclusion Among 20 yeast isolates, 5 isolates showed increased growth under stress tolerance. It can be concluded that the screened yeast isolates LM, MR, GOI, GII2 and WI can serve as promising probiotics in various fields of food industry.Key words:  Acid tolerance; bile tolerance, cholesterol removal, probiotics, yeast.

Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1860
Author(s):  
Patricia Diez-Echave ◽  
Izaskun Martín-Cabrejas ◽  
José Garrido-Mesa ◽  
Susana Langa ◽  
Teresa Vezza ◽  
...  

Limosilactobacillus reuteri INIA P572 is a strain able to produce the antimicrobial compound reuterin in dairy products, exhibiting a protective effect against some food-borne pathogens. In this study, we investigated some probiotic properties of this strain such as resistance to gastrointestinal passage or to colonic conditions, reuterin production in a colonic environment, and immunomodulatory activity, using different in vitro and in vivo models. The results showed a high resistance of this strain to gastrointestinal conditions, as well as capacity to grow and produce reuterin in a human colonic model. Although the in vitro assays using the RAW 264.7 macrophage cell line did not demonstrate direct immunomodulatory properties, the in vivo assays using a Dextran Sulphate Sodium (DSS)-induced colitic mice model showed clear immunomodulatory and protective effects of this strain.


2018 ◽  
Vol 26 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Barbara Kazuń ◽  
Krzysztof Kazuń ◽  
Joanna Żylińska ◽  
Andrzej K. Siwicki

Abstract The presence of lactic acid bacteria (LAB) favors the stabilization of intestinal flora, facilitates digestion, improves the assimilability of fodder, and has an immunomodulatory effect on the immune system. According to current research, the application of LAB following antibiotic treatment prevents the development of opportunistic bacteria inhabiting the digestive tract. In the study the potential probiotic properties of Lactobacillus plantarum strains, which can be administered as an alternative to antibiotic treatment in aquaculture, were investigated under in vitro conditions. The strains of L. plantarum were characterized for important properties such as the ability to grow in the presence of 10% fish bile, a tolerance of low pH, and antagonism to pathogens dangerous for fish such as Aeromonas salmonicida and Pseudomonas fluorescens; therefore, they meeting the criteria for strains with probiotic properties. In view of currently increasing resistance to antibiotics and a decrease of their efficiency, probiotic bacteria can serve to support immunity to infections in the future.


Hepatology ◽  
2020 ◽  
Author(s):  
Rachida Amzal ◽  
Alice Thébaut ◽  
Martine Lapalus ◽  
Marion Almes ◽  
Brigitte Grosse ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Guesh Mulaw ◽  
Tesfaye Sisay Tessema ◽  
Diriba Muleta ◽  
Anteneh Tesfaye

Probiotics are live microorganisms which when consumed in large number together with a food promote the health of the consumer. The aim of this study was to evaluate in vitro probiotic properties of lactic acid bacteria (LAB) isolated from traditional Ethiopian fermented Teff injera dough, Ergo, and Kocho products. A total of 90 LAB were isolated, of which 4 (4.44%) isolates showed 45.35–97.11% and 38.40–90.49% survival rates at pH values (2, 2.5, and 3) for 3 and 6 h, in that order. The four acid-tolerant isolates were found tolerant to 0.3% bile salt for 24 h with 91.37 to 97.22% rate of survival. The acid-and-bile salt-tolerant LAB isolates were found inhibiting some food-borne test pathogenic bacteria to varying degrees. All acid-and-bile-tolerant isolates displayed varying sensitivity to different antibiotics. The in vitro adherence to stainless steel plates of the 4 screened probiotic LAB isolates were ranged from 32.75 to 36.30% adhesion rate. The four efficient probiotic LAB isolates that belonged to Lactobacillus species were identified to the strain level using 16S rDNA gene sequence comparisons and, namely, were Lactobacillus plantarum strain CIP 103151, Lactobacillus paracasei subsp. tolerans strain NBRC 15906, Lactobacillus paracasei strain NBRC 15889, and Lactobacillus plantarum strain JCM 1149. The four Lactobacillus strains were found to be potentially useful to produce probiotic products.


1997 ◽  
Vol 17 (5) ◽  
pp. 2679-2687 ◽  
Author(s):  
S Minoguchi ◽  
Y Taniguchi ◽  
H Kato ◽  
T Okazaki ◽  
L J Strobl ◽  
...  

RBP-Jkappa is a sequence-specific DNA binding protein which plays a central role in signalling downstream of the Notch receptor by physically interacting with its intracellular region. Although at least four Notch genes exist in mammals, it is unknown whether each Notch requires a specific downstream signalling molecule. Here we report isolation and characterization of a mouse RBP-Jkappa-related gene named RBP-L that is expressed almost exclusively in lung, in contrast to the ubiquitous expression of RBP-Jkappa. For simplicity, we propose to call RBP-Jkappa RBP-J. The RBP-L protein bound to a DNA sequence almost identical to that of RBP-J. Surprisingly, RBP-L did not interact with any of the known four mouse Notch proteins. Although we found that RBP-L and EBNA-2 cooperated in transcriptional activation, they did not show significantly strong protein-protein interaction that can be detected by several in vivo and in vitro assays. This is again in contrast to physical association of RBP-J with EBNA-2. Several models to explain functional interaction between RBP-L and EBNA-2 are discussed.


2019 ◽  
Author(s):  
Guesh Mulaw ◽  
Tesfaye Sisay ◽  
Diriba Muleta ◽  
Anteneh Tesfaye

AbstractProbiotics are live microorganisms which when consumed in large number together with a food promote the health of the consumer. The aim of this study was to evaluatein vitroprobiotic properties of lactic acid bacteria (LAB) isolated from traditional Ethiopian fermentedTeff injeradough,ErgoandKochoproducts. A total of 90 LAB were isolated, of which 4 (4.44%) isolates showed 45.35-97.11% and 38.40-90.49% survival rate at pH values (2, 2.5 and 3) for 3 and 6 h in that order. The four acid tolerant isolates were found tolerant to 0.3% bile salt for 24 h with 91.37 to 97.22% rate of survival. The acid-and-bile salt tolerant LAB isolates were found inhibiting some foodborne test pathogenic bacteria to varying degrees. All acid-and-bile tolerant isolates displayed varying sensitivity to different antibiotics. Thein vitroadherence to stainless steel plates of the 4 screened probiotic LAB isolates were ranged from 32.75 to 36.30% adhesion rate. The four efficient probiotic LAB isolates that belonged toLactobacillusspecies were identified to strain level using 16S rDNA gene sequence comparisons and namely wereLactobacillus plantarumstrain CIP 103151,Lactobacillus paracaseisubsp. tolerans strain NBRC 15906,Lactobacillus paracaseistrain NBRC 15889 andLactobacillus plantarumstrain JCM 1149. The fourLactobacillusstrains were found to have potentially useful to produce probiotic products.


Author(s):  
A. M. Adisa ◽  
B. O. T. Ifesan ◽  
V. N. Enujiugha ◽  
A. B. Adepeju

Background: The term probiotics have been described as live microorganisms associated with fermented foods that confer health benefit to the host. For a long time, researches into the world of probiotics have extensively and predominantly centred upon species of lactic acid bacteria and until recently Saccharomyces cerevisiae, as the only well-defined and proven probiotic yeast strain. The purpose of this study was to isolate and characterise the yeast species associated with the fermentation of wholegrain millet sourdoughs and investigate in vitro the possible probiotic potential of the isolates. Methodology: Wholegrain millet sourdoughs were prepared by spontaneous fermentation of the flours with tap water in the ratio 1:1 (w/v) for 48 h at 28 ± 2ºC through backslopping. A total of twenty five yeasts were identified based on their cultural, morphological and biochemical characteristics. The selected isolates were characterized to species level using API 20 C AUX test identification kit. Probiotic properties examined included bile salt and acid tolerance under conditions simulating the human gastrointestinal tract (GIT) and positive antagonistic activity against selected pathogens following well established procedures. Results: The selected isolates investigated were characterized to belong to species of Saccharomyces and Kluveromyces. All of the isolates were discovered to exhibit sufficient survival under acidic pH of 2.0 with values ranging from 1.0log cfu ml-1 to 7.8log cfu ml-1 and showed high resistance to bile salt with values ranging from 63-99%. They also exhibited good antimicrobial activity against enteric pathogens of E. coli, Salmonella typhimurium, Staphylococcus aureus, Klebsiella pneumonia, Streptococcus pyogenes, Proteus vulgaris and Pseudomonas sp. Conclusion: Millet sourdoughs can serve as an affordable nutritionally healthy substrate for delivery of probiotics to the gastro-intestinal tract, thereby proffering basic health functionality. This study allowed to isolate and to identify yeast species present in millet sourdoughs with technological potential for sourdough applications.


2011 ◽  
Vol 48 (3) ◽  
pp. 199-204 ◽  
Author(s):  
Jacy Alves Braga de Andrade ◽  
Edna Freymüller ◽  
Ulysses Fagundes-Neto

CONTEXT: Enteroaggregative Escherichia coli strains have been associated with persistent diarrhea in several developing countries. In vivo procedures with animal models, in vitro assays with cellular lines and in vitro organ culture with intestinal fragments have been utilized to study these bacteria and their pathogenicity. OBJECTIVE: The present experimental research assessed the pathogenic interactions of three enteroaggregative Escherichia coli strains, using the in vitro organ culture, in order to show the adherence to different regions of both, the ileal and the colonic mucosa and demonstrate possible mechanisms that could have the participation in the prolongation of diarrheiogenic process. METHODS: This study used intestinal fragments from terminal ileum and colon that were excised from pediatric patients undergoing intestinal surgeries and from adult patients that underwent to colonoscopic procedures. Each strain was tested with three intestinal fragments for each region. Tissue was fixed for scanning electron microscopic analysis. RESULTS: These bacteria colonized ileal and colonic mucosa in the typical stacked-brick configuration in the ileum and colon. In both regions, the strains were seen over a great amount of mucus and sometimes over the intact epithelium. In some regions, there is a probable evidence of effacement of the microvilli. It was possible to see adhered to the intestinal surface, bacteria fimbrial structures that could be responsible for the adherence process. CONCLUSION: In order to cause diarrhea, enteroaggregative Escherichia coli strains adhere to the intestinal mucosa, create a mucoid biofilm on the small bowel surface that could justify the digestive-absorptive abnormalities and consequently, prolonging the diarrhea.


2017 ◽  
Vol 73 (7) ◽  
pp. 412-417
Author(s):  
Felix N. Toka

Gamma/delta (γδ) T cells in cattle account for an abundant T cell population. However, little is known regarding the function of γδ T cells as immune cells compared to αβ T cells. Not many pathogen-related antigens have been defined and known to stimulate γδ T cells. To address this information gap, we constructed a soluble receptor for bovine γδ T cells (sγδTCR) that was later used to identify two proteins (156 kDa and 102 kDa) or protein fragments expressed by bovine coronavirus (BCov). The molecular weight of the larger protein suggests it could be the spike glycoprotein of BCov. Subsequently, we used the identified viral proteins to study the reactivity of bovine γδ T cells. In vitro assays showed that purified preparations of the two proteins stimulated WC1+ γδ T cells isolated from cattle. A 4-fold increase in IFN production and a significantly higher expression of MHC class II was observed. However, these viral ligands could not stimulate γδ T cells to synthesize IL-8 or GM-CSF, known to be produced by γδ T cells when stimulated with bacterial antigens. Although the γδ T cells assessed here appeared activated by way of IFN and MHC II expression, surface markers such as CD2, CD25, CD44, CD62L and CD335 were not expressed at significant levels. Further, the activation elicited by viral ligands was not sufficient to induce cytotoxic capability in γδ T cells in vitro as measured by a flow cytometry-based cytotoxicity assay. This in vitro study shows that WC1+ γδ T cells can directly recognize viral antigen


2003 ◽  
Vol 69 (8) ◽  
pp. 4743-4752 ◽  
Author(s):  
Dora I. A. Pereira ◽  
Anne L. McCartney ◽  
Glenn R. Gibson

ABSTRACT This study evaluated the use of a bile-salt-hydrolyzing Lactobacillus fermentum strain as a probiotic with potential hypocholesterolemic properties. The effect of L. fermentum on representative microbial populations and overall metabolic activity of the human intestinal microbiota was investigated using a three-stage continuous culture system. Also, the use of galactooligosaccharides as a prebiotic to enhance growth and/or activity of the Lactobacillus strain was evaluated. Administration of L. fermentum resulted in a decrease in the overall bifidobacterial population (ca. 1 log unit). In the in vitro system, no significant changes were observed in the total bacterial, Lactobacillus, Bacteroides, and clostridial populations through L. fermentum supplementation. Acetate production decreased by 9 to 27%, while the propionate and butyrate concentrations increased considerably (50 to 90% and 52 to 157%, respectively). A general, although lesser, increase in the production of lactate was observed with the administration of the L. fermentum strain. Supplementation of the prebiotic to the culture medium did not cause statistically significant changes in either the numbers or the activity of the microbiota, although an increase in the butyrate production was seen (29 to 39%). Results from this in vitro study suggest that L. fermentum KC5b is a candidate probiotic which may affect cholesterol metabolism. The short-chain fatty acid concentrations, specifically the molar proportion of propionate and/or bile salt deconjugation, are probably the major mechanism involved in the purported cholesterol-lowering properties of this strain.


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