Investigation Of The Biological Characteristics Of Lactic Acid Bacteria Isolated From Traditional Fermented Pickle Samples In The Sichuan Province

One hundred and sixteen Lactic acid bacterial strains including 94 lactobillus and 22 lactoccus were isolated from the 34 traditional fermented pickle samples. The assay technique of numerical taxonomy was used to study the phenotypic properties and diversity of the isolates and the 15 representative strains. The ability of bacterocin production of the isolates were tested .The isolates with higher bacterocin production were used as inoculants in pickle fermentation. The nitrite concentration was determined with the control in the fermentation process. Base on the results of numerical taxonomy, the genus and species of the isolates were identified.According to the results of numerical taxonomy, only 10 lactococcus strains were divided into 4 clusters at the similarity level of 75%, which indicated the complex physiological properties of LAB from the different regions and different materials. At the similarity level of 75%, 94 lactobacillus strains were divided into 24 phenotypic groups, and the strains from the same sample were dispersed in different groups. The results showed that the lactobacillus strains from the traditional fermented pickle in the Sichuan Province had high phenotypic diversity. By the physiological and biochemical tests, the lactobacillus strains were identified as the following species, L.casei subsp.casei, L.coryniformis, L.acidophilus, L.plantarum, L.helveticus, Lactobacillus delbrueckii subsp. bulgaricus, L.salivarius subsp.salicinius, L.pentosus, L.graminis, L.viridescens, L.intestinalis, L.zeae, L.casei subsp.pseudoplantarum, L.curvatus, L.coryniformis subsp.torquens, L.murinus, L.parabuchneri, L.bifermentans, L.conllinoides, L.halotolerans, L.alimentariu.Among 22 cocci strains ,they were identified to be 6 species including Lactococcus lactis subsp.lactis, Lactococcus lactis subsp.lactis, L.plantarum, E.faecalis, E.faecium, Streptococcus.By the niujin cup test, five lactobacillus strains were screened out to be the bacterocin producers among the 116 isolates. These strains were inoculated into the pickle. The results indicated that the nitrite concentration was significantly lower than that of natural fermentation. The five...