Phylogenetic relationship and probiotic properties of dominant lactic acid bacteria isolated from whole barley sourdough
Subject Areas : Food Microbial ContaminationMaryam Ebrahimi 1 , Alireza Sadeghi 2 , Balal Sadeghi 3
1 - Cereal Health Research Center, Golestan University of Medical Science
2 - Department of Food Science and Technology, Faculty of Food Science, Gorgan University of Agricultural Sciences and Natural Resources
3 - Department of Food Hygiene, Faculty of Veterinary Medicine, Shahid Bahonar
University of Kerman
Keywords: Phylogenetic relationship, Barley sourdough, Probiotic properties, LAB isolate,
Abstract :
The aims of this study were evaluating the probiotic properties and phylogenetic relationship of dominant lactic acid bacteria (LAB) isolated from whole barley sourdough. At the beginning, dominant LAB isolates were identified by specific PCR. Then probiotic properties of the isolates including survival in simulated conditions of gastrointestinal tract, antagonistic effects against Staphylococcus aureus, Listeria monocytogenes, Escherichia coliand Salmonella enterica as foodborne indicator bacteria, ability of aggregation with E. coli and S. enterica as infection agents of intestine and resistance of these LAB isolates against some of routine antibiotics were investigated. For determination of phylogenetic relationship between LAB isolates, maximum likelihood method was also used. Sequencing results of PCR products lead to identification of Lactobacillus brevis, Lactobacillus curieae, Pediococcus pentosaceus and Weissella cibaria as dominant isolated LAB from whole barley sourdough. Among mentioned isolates, L. brevis had significantly (P<0.05) higher survival in pH 2 and 0.3% bile salt in comparison to other isolates. Inhibition zone diameter of foodborne indicator bacteria in the presence of P. pentosaceus was the highest. P. pentosaceus had also significantly (P<0.05) more effective aggregation ability towards E. coli and S. enterica than the others and four LAB isolates were resistant to vancomycin. Analysis of aligned sequences in phylogenetic tree showed that L. curieae and P. pentosaceus had very closely phylogenetic relationship while, the most genetic difference was observed between L. brevis and W. cibaria.
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