Characterization and Purification of a Bacteriocin Produced by a Potential Probiotic Culture, Lactobacillus acidophilus 30SC

¹ Department of Food Science & Technology, New York State Agricultural Experiment Station, Cornell University, Geneva, NY 14456-0462
² Department of Animal Science, Korea University, Seoul 136-701, Korea

Lactobacillus acidophilus 30SC was tested for its potential as a probiotic culture. The strain exhibited good acid tolerance in an artificial gastric solution as well as bile resistance in media containing 0.3% bile acids. The strain produced a heat-stable antimicrobial compound that was shown to be proteinaceous in nature and, therefore, referred to as a bacteriocin. The bacteriocin was active over a wide pH range and inhibited a number of Gram-positive bacteria including Listeria ivanovii and pathogenic strains. The bacteriocin was purified by 50% ammonium sulfate precipitation followed by hydrophobic interaction column chromatography. The SDS-PAGE of the active fractions resulted in a single band with estimated molecular mass of 3.5 kDa. These results demonstrate the potential of L. acidophilus 30SC as a probiotic culture that can be utilized in the manufacturing of dairy foods and dietary supplements.

Key Words: probiotics • bacteriocin • Lactobacillus acidophilus

Submitted on February 29, 2000