Characterization and Antibacterial Mode of a Novel Bacteriocin with Seven Amino Acids from Lactobacillus plantarum in Guizhou Salted Radish

Traditional Chinese fermented vegetables are excellent probiotic food with probiotic lactic acid bacteria that are benefical to the health. A novel bacteriocin with molecular weight, 825 Da was found successfully from Lactobacillus plantarum 163, which was isolated from Guizhou salted radish. The complete amino acid sequence was speculated as YVCASPW based on the mass spectrometry, and was named as bacteriocin 163-1. The bacteriocin 163-1 was highly thermostable and stability over a broad pH range (pH 3-6), sensitive to protease K and pepsin, and exhibited a wide range of antimicrobial activity not only against lactic acid bacteria (LAB) but also against other foodborne pathogens including Gram-positive and Gram-negative bacteria. Bacteriocin 163-1 could disrupt the cell membrane of bacteria. The observations of the transmission electron microscopy and laser confocal microscopy on the cell membrane of Escherichia coli and Staphylococcus aureus showed that bacteriocin 163-1 could result in forming pores on the cell membrane and then cytolysis of the bacteria. The new bacteriocin with broad-spectrum antibacterial activity will be useful in preservation of vegetable, fruit and food as well agricultural bio-controlling.