A novel bacteriocin with a broad inhibitory spectrum produced by Lactobacillus sake C2, isolated from traditional Chinese fermented cabbage

By excluding the effects of organic acids and hydrogen peroxide, strain C2 producing a bacteriocin strongly inhibited Staphylococcus aureus ATCC 63589 and Escherichia coli ATCC 25922 was selected from 300 lactic acid bacteria isolated from traditional Chinese fermented cabbage. Strain C2 was identified as Lactobacillus sakei by phenotypical and physiological tests and 16S rDNA identification. This bacteriocin, which was designated sakacin C2, was purified by cold ethanol and Sephadex G50 column chromatography for further studies. The molecular weight of sakacin C2 was 5.5 kDa by Tris-Tricine SDS–PAGE, which was the largest among all known sakacins. Sakacin C2 exhibited a wide range of antimicrobial activity, strong heat stability (15 min at 121 °C) and pH stability (pH 3.0–8.0). Sakacin C2 was sensitive to protease but insensitive to lipase, α-amylase and β-amylase. These characters suggested that sakacin C2 was a novel Class II bacteriocin with a broad inhibitory spectrum and might broaden the application range of bacteriocins from LAB in the food industry.