Isolation and characteristics of lactic acidbacteria from Guangzhou pickles

In the present study，14 strains of lactic acid bacteria（LAB）were isolated from Guangzhou pickleswhich were randomly bought from local market. Their inducing hemolysis，producing biogenic amine（histamine，tyramine and phenylethylamine），antimicrobial activity against 39 different sources of pathogens，acid tolerance，bile tolerance et al. were investigated. Results showed that none of the 14 tested strains induced hemolysis on sheepblood agar（γ-hemolytic）；and they produced no biogenic amine（histamine，tyramine and phenylethylamine）；the14 isolated LAB strains had different antimicrobial activity against 39 different pathogens，among them，P1，P2 andP11 had the stronger antimicrobial activity，they showed 34/39，33/39 and 33/39 positive antimicrobial activities，respectively，moreover，P2（cell-free supernatants）showed the strongest antimicrobial activity（+++，diameter ofinhibition zone>15 mm）on 13 pathogens，which was the highest growth inhibitory rate of all；concerning acid toleranceresults，P2 strains showed acid tolerance at pH 2.5 and pH 3.5，while the other two strains（P1 and P11）did not；withrespect to bile tolerance，P2 and P11 showed bile tolerance at the bile density of 0.5%，1.0% and 1.5%，while P1 did not.Finally，analysis of partial 16S rDNA demonstrated that P2 was identified as Lactobacillus salivarius（identity of 99%）.