Production of Bacteriocin by Lactococcus lactis subsp. lactis NFH-NM9 Isolated from Mackerel Nare-zushi in Wakasa, Japan

Abstract

　Bacteriocins produced by lactic acid bacteria are natural antimicrobials that have long been consumed via fermented foods. Because of their safety and excellent properties, it has been the focus of renewed efforts to identify novel bacteriocins, and their producing microorganisms as an effective natural food preservative. In this study, we report the first isolation of a bacteriocin-producing lactic acid bacterium, named Lactococcus lactis subsp. lactis NFH-NM9, from Mackerel Nare-zushi in Wakasa, Japan. The analysis of the estimated molecular weight and structural gene sequence revealed that the bacteriocin produced by the strain is nisin F. For the first time, the culture supernatant of this strain was found to exhibit antibacterial activity against Listeria monocytogenes, albeit against some strains. In the future, the precise antimicrobial activity and antimicrobial spectrum obtained by isolation and purification of nisin F are expected to expand the range of applications of this bacteriocin.