Purification and Partial Amino Acid Sequence of Pentocin 31-1, an Anti-Listeria Bacteriocin Produced by Lactobacillus pentosus 31-1

Pentocin 31-1, an anti-Listeria bacteriocin produced by Lactobacillus pentosus 31-1 from the traditional Chinese fermented Xuan-Wei ham, was successfully purified by the pH-mediated cell adsorption-desorption method and then purified by gel chromatography with Sephadex G-10. The purification resulted in a 1,381.9-fold increase in specific activity with a yield of 76.8% of the original activity. Using Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), the molecular mass of the purified peptide was found to be between 3,500 and 6,400 Da, and bacteriocin activity was confirmed by overlayer techniques. When subjected to mass spectrometry analysis, the protein was highly pure and its molecular mass was 5,592.225 Da. The partial N-terminal sequence of pentocin 31-1 was the following: NH2-VIADYGNGVRXATLL. Compared with the sequence of other bacteriocins, pentocin 31-1 has the consensus sequence YGNGV in its N-terminal region, and therefore it belongs to the class IIa of bacteriocins.