Screening and characterization of bacteriocinogenic lactic acid bacteria from Jeot-gal, a Korean fermented fish food

Abstract

Bacteriocins are classified as proteins which are produced by heterogeneous groups of bacteria, having an antimicrobial effect of the closely related organisms. Recently, bacteriocins derived from lactic acid bacteria and other food-related organisms have been the subject of much research on potential food biopreservatives. The goal of this study was to screen and characterize the bacteriocinogenic lactic acid bacteria from Jeot-gal (commercial fermented fish foods). All bacteriocinogenic isolates were identified as lactic acid bacteria. Isolates NK24, NK34, and SA72 were tentatively identified as Lactococcus lactis, whereas isolate SA131 was recognized as Lactobacillus brevis, according to the API 50 CHL kit database. All antimicrobial substances produced from four lactic acid bacteria isolates completely lost their antibacterial activity after being treated with some proteases, indicating to their proteinaceous nature. The bacteriocin produced from isolates NK24, NK34, and SA72 showed a broad spectrum of activity when compared to those produced from isolate SA131. All bacteriocins isolated during the course of this study showed a bactericidal mode of inhibition.