Characterization and the influence of milk solids-not-fat on the bacteriocin produced by Lactococcus lactis subsp. lactis S20 isolated from Chinese sauerkraut, a traditional fermented vegetable

摘要: Lactococcus lactis subsp. S20, a bacteriocinogenic lactic acid bacterium, was isolated from Chinese sauerkraut. This strain produced the highest bacteriocin activity (1280 AU/ml) against Listeria monocytogenes ATCC 19115 after 20 h of culture at 30 °C in MRS broth, although our results demonstrate that TSB suitable alternative production medium. Bacteriocin S20 exhibited inhibitory most Gram-positive food pathogens but did not inhibit growth Gram-negative bacteria. Results stability tests indicate resistant to trypsin, amylase, and lipase sensitive proteinase K, α-chymotrypsin, pepsin. stable over wide range pH (pH 3–9) temperatures up 70 for 15 min. The dropped 40 AU/ml autoclaving 121 Taken together, molecular studies suggest is closely related nisin A. Based on adsorption study, 6 7 were optimal S20. cells showed higher than producer strain. However, observed this study suggests bound randomly cell membrane. general medium relatively MRS. Conversely, recovery yield extracted broth. In addition, an effective antilisterial skim milk containing <12 % (w/v) solids-not-fat.