title: Purification and Partial Identification of Bacteriocin ISK-1, a New Lantibiotic Produced by Pediococcus sp. ISK-1.
abstract: Bacteriocin ISK-1 is a proteinaceous inhibitory substance produced by Pediococcus sp. ISK-1 isolated from well-aged Nukadoko. Bacteriocin ISK-1 was purified by acid treatment, ammonium sulfate precipitation, cation-exchange chromatography, and reversed-phase HPLC from the culture supernatant of Pediococcus sp. ISK-1. Purification of bacteriocin ISK-1 resulted in a 30-fold increase in the specific activity and the recovery was 17%. Molecular mass of bacteriocin ISK-1 measured by fast atom bombardment-mass spectrometry was 2,960. The amino acid composition analysis of bacteriocin ISK-1 showed that it contained unusual amino acids such as lanthionine and/or 3-methyllanthionine, which is a characteristic of lantibiotics. The N-terminal amino acid sequence analysis indicated the first seven N-terminal amino acid residues as NH2-K-K-K-S-G-V-I. The primary sequence showed significant similarity to the lantibiotics lacticin 481 from Lactococcus lactis and variacin from Micrococcus varians, which suggests that bacteriocin ISK-1 is a novel lantibiotic belonging to a lacticin-481 type.
authors.affiliation: a Laboratory of Microbial Technology, Department of Food Science and Technology, Faculty of Agriculture, Kyushu University.
authors.forename: H
authors.initials: H
authors.lastname: Kimura
authors.affiliation: a Laboratory of Microbial Technology, Department of Food Science and Technology, Faculty of Agriculture, Kyushu University.
authors.forename: H
authors.initials: H
authors.lastname: Matsusaki
authors.affiliation: a Laboratory of Microbial Technology, Department of Food Science and Technology, Faculty of Agriculture, Kyushu University.
authors.forename: T
authors.initials: T
authors.lastname: Sashihara
authors.affiliation: a Laboratory of Microbial Technology, Department of Food Science and Technology, Faculty of Agriculture, Kyushu University.
authors.forename: K
authors.initials: K
authors.lastname: Sonomoto
authors.affiliation: a Laboratory of Microbial Technology, Department of Food Science and Technology, Faculty of Agriculture, Kyushu University.
authors.forename: A
authors.initials: A
authors.lastname: Ishizaki
keywords: Nukadoko; Pediococcus; bacteriocin; lantibiotic