Screening of Bacteriocin Producing Lactic Acid Bacteria for Probiotic Properties

ABSTRACT

The concept of providing functional foods including beneficial probiotic components is gaining attention in recent years. Therefore, this study was aimed to isolate potential probiotic Lactic Acid Bacteria (LAB) from various sources. A total of 66 LAB strains were selectively isolated from different sources using MRS agar medium. Out of 66 isolates, only 7 were found to be bacteriocin producers and showed antibacterial activity against S. aureus and E. coli. All the 7 isolates were screened for probiotic properties like bile tolerance (1000 to 10,000 ppm bile salt concentration), acidic pH tolerance (pH 1 to 3.5), auto aggregation potential and cell surface hydrophobicity. Isolates RM4 & RM7 were able to tolerate bile salt concentration of up to 10,000 ppm. For acidic pH tolerance, both the isolates RM4 & RM7 were able to grow at pH 3.5 to 2. The autoaggregation potential and cell surface hydrophobicity of RM7 was found to be 40.88% and 54.58% respectively but these properties were found to be below 40 % for RM4. Therefore isolate RM7 fulfilled the criterion to be identified as a possible potential probiotic strain.

Key words: Lactic acid bacteria, Probiotics, Bile tolerance, Hydrophobicity, Autoaggregation

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