Production of an Amylase-Sensitive Bacteriocin by an Atypical Leuconostoc paramesenteroides Strain.

An atypical Leuconostoc paramesenteroides strain isolated from retail lamb produced a bacteriocin, leuconocin S, that was inactivated by alpha-amylase, trypsin, alpha-chymotrypsin, protease, and proteinase K but not by lipase or heat treatment at 60 degrees C for 30 min. Supernatants from culture broths produced two glycoprotein bands on sodium dodecyl sulfate-polyacrylamide gels; these had molecular weights of 2,000 and 10,000 and activity against Lactobacillus sake ATCC 15521. The crude bacteriocin preparation was bacteriostatic and dissipated proton motive force. Bacteriocin activity was produced over a wide pH range (5.2 to 7.9) on buffered agar medium, with an optimum pH of pH 6.15. The optimum pH for production in broth was 6.5 to 7.0.