Screening and identification of bacteriocin produced by lactic acid bacteria

In order to obtain bacteriocin producing strains, lactic acid bacterias were isolated from European salami sausages, Xinjiang cheeses, self fermented pickles, Korean cabbages in chili sauce by using calcium dissolving ring and Oxford cup double plate methods. The strains were identified to species on the basis of morphological, physiological, biochemical characteristics and 16 S r DNA sequence analysis, and the bacteriocin related gene was analyzed to determine bacteriocin types.The results showed that 5 strains ( SA102, SA104, N105, N107, N108) had better antibacterial activity among the 206 strains.The antimicrobial role of this bacteriocin was confirmed by eliminating the interference of organic acid, hydrogen peroxide and by conducting protease sensitivity. Two of these 5 strains were Lactobacillus casei and three were Lactobacillus plantarum.The rapid screening of PCR amplification showed that N107, N108 contained IIb plantaricins JK gene.Physiological and biochemical tests confirmed that 5 strains with good biological safety produced no gas, ammonia, hydrogen sulfide, viscosity and pigment.p H stability and temperature stability of the crude extract of fermentation were explored to provide some information and resources for the further study of bacteriocin.