Screening of Bifidobacterium strains for bacteriocin production

Thirteen strains of bifidobacteria (Bifidobacterium ) were examined for bacteriocin production. One strain among these produced bacteriocin which is active against lactic streptococci strains and against other species of Bifidobacterium, Clostridium and Lactobacillus , but not against Gram-negative bacteria such as Pseudomonas, Klebsiella, Serratia and Escherichia coli . Bacteriocin activity was inhibited by proteolytic enzymes, but not by heating 15 min or 30 min at 100 degree C, and it was resistant for 15 min at 121 degree C and active at pH between 2 to 10.