Probiotic Potential of Lactobacillus plantarum Isolated from Zabady

Twenty one isolates of lactic acid bacteria (LAB) were isolated from Zabady, an Egyptian yoghurt, and screened
for their antibacterial activities against 8 pathogens (Bacillus cereus ATCC 49064, Clostridium perfringens ATCC
13124, Escherichia coli, Listeria innocua ATCC 33090, Listeria monocytogenes ATCC 19116, Listeria ivanovii Li4
(pVS2), Salmonella enterica ATCC 25566, and Yersinia enterocolitica ATCC 23715) as indicator strains. One isolate
was selected as a promising candidate.The selected isolate was identified as Lactobacillus plantarum by phenotypic
and genotypic methods. Afterwards, the identified isolate was evaluated for a number of probiotic characteristics including
tolerance to simulated gastric juice, bile salt resistance, cell surface hydrophobicity, resistance to low phenol
concentration, autoggregation, coaggregation, adhesion to rabbit epithelial cells, and reduction of cholesterol. This
isolate showed; sensitivity to simulated gastric juice adjusted at pH 2.0 - 3.5, tolerance to 0.3% bile concentration
and antimicrobial activity against Salmonella enterica ATCC 25566 ((25600 Activity unit /ml), was Bacillus cereus
ATCC 49064 (25600 Activity unit /ml), Yersinia enterocolitica ATCC 23715 (400 Activity unit /ml) and L. monocytogenes
ATCC 19116 (200 Activity unit /ml) that is probably due to production of active peptides. Furthermore,
the results demonstrate that this isolate was highly tolerated to different tested phenol concentrations, moderate cell
surface hydrophobicity, weak autoaggregating and reasonable adhesion level to rabbit epithelial cell.