Bioprospecting for probiotics and other technological aspects of the bacteria isolated from goat milk.

Abstract

Goat milk is a superior nutritional source for human beings. It possesses probiotic, prebiotic, immunomodulatory actions and inhibits the adherence of pathogenic bacteria. The microbiota of raw goat milk is a rich source of novel bacteriocin-producing lactic acid bacteria (LAB). LAB were evaluated for their probiotic attributes, i.e. acid, bile tolerance, and safety assessment. The antimicrobial activity of LAB isolated from goat milk was assessed against the 10 most common indigenous bacterial pathogens confirmed through 16S rRNA sequencing. The strains LAB GM8 and GM121 showed high tolerance to acidic pH while GM121 showed tolerance to high bile salt concentrations. LAB GM121 showed susceptibility to eight antibiotics which meets the safety requirements regarding phenotypic resistance evaluation. Out of 10, 4 LAB GM8, GM26, GM121, GM122 displayed antibacterial activity against Pseudomonas aeruginosa and Staphylococcus aureus, demonstrating their ability to produce bioactive compounds. So, based on acid, bile tolerance, and safety requirements, it can be concluded that the GM121 has the potential to be explored as probiotic strains in the dairy industry. Bacterial isolates (n-24) were screened for exopolysaccharide production and amylase activity; Bacillus paralicheniformis GM75 showed good exopolysaccharide production and antimicrobial activity while Bacillus cereus GM56 showed maximum amylase activity.