Screening of health beneficial microbes with potential probiotic characteristics from the traditional rice-based alcoholic beverage, haria

Abstract

Fermented foods are natural habitats of various food-grade microorganisms which not only fortify the food material with bioactive molecules, but they could directly exert health beneficial effect to the consumers. The present study aimed to screen the microbial consortium of haria (a traditional alcoholic rice beverage), for therapeutic potentiality. Twenty-nine fermented beverage samples were collected from different areas of Bankura District (West Bengal, India).Initially, 45 dominant bacterial isolates were purified from the collected samples. From these, 3 microorganisms were screened out based on growth and acidification kinetics: these proved to be Bifidobacterium sp. (MKK4), Pediococcus lolli (MKK21), and Lactobacillus sp. (MKK37) isolates. Finally, based on a cumulative probiotic score, MKK4 (Bifidobacterium sp.) was selected for further studies. The ubiquitous presence of this strain in the collected samples was confirmed through PCR-DGGE fingerprinting. This strain was considerably stable in simulated acid and bile solutions; it also exhibited strong auto-aggregation and cell surface hydrophobicity of 82% and 53%, respectively. Under conditions of nutrient depletion, the isolate was capable to form biofilm (66.3%). The selected bacterium showed strong antimicrobial activities against Shigella dysenteriae MB14, Salmonella typhi E 1590, Micrococcus luteus ATCC 9341, Staphyloccus aureusMB13, Vibrio cholerae K510, and Escherichia coli ATCC 25922 isolates. These results suggest that the food-borne Bifidobacterium sp. MKK4 can be used as potent probiotic agent.