Studies on bacteriocin producing functional strains of streptococcus thermophilus with probiotic attributes

Consumers’ demand and market potential of fermented food and dairy products calls for innovation in food and dairy processing and needs novel starter strains to boom food industry. Nine strains of bacteriocin producing Streptococcus thermophilus with sound technological properties isolated from milk and milk products were evaluated for in-vitro acid and bile tolerance in simulated gastro-intestinal environment, adherence to cell surface and antibiotic sensitivity profile. All the nine strains were found to be acid and bile tolerant with some degree of variability. The percent hydrophobicity of studied strain was ranging from 5% to 33.5% with all the tested hydrocarbons. All the strains of S. thermophilus were sensitive to antibiotic ofloxacin, vancomycin, polymixin B and ciprofloxacin while showed variable behavior towards remaining 19 antibiotics. Three strains namely PMD9, PMK20 and PMl31 were found to possess appreciable probiotic properties in all respect and could be novel agents for their exploitation as functional dairy starters. Further use of these products could be for fortifying these products in yoghurts for health benefits, or countering antibiotic resistance.