Isolation And Identification Of Wine Lactic Acid Bacteria From Different Regions

Wine fermentation is a complex process performed by yeast and lactic acid bacteria(LAB). Malolactic fermentation (MLF) carried out by LAB usually takes place after alcoholicfermentation (AF). During MLF, L-malic acid is decarboxylated to L-lactic acid and CO2. Theactivity of the bacteria performing the MLF improves wine quality because the acidity of thewine is been decreased, the organoleptic characteristics and the stability of microorganisms inwine are improved and so on. However the excellent local fermentation strains is more a lack,so screen excellent brewing strains is necessary.In this study, lactic acid bacteria was isolated from MLF spontaneously started wine ofseveral large regions, their species were identified, the intraspecific genetic diversity of strainswere analyzed by single-enzyme amplified fragment length polymorphism (SE-AFLP) andtaking advantage of the RAPD technique verified the lactic acid bacteria acid resistance gene.1: Nearly200strains were isolated from11wine samples of four regions,90of themwere identified by biochemical identification and16SrRNA sequencing and the result is:11ofthem are Oenococcus oeni;10of them are Lactobacillus brevis,9of them are Lactobacillusmali,10of them are Pediocooccus parvulus,23of them are Leuconostoc mesenteroides and27of them are Lactobacillus plantarum.2: Using SE-AFLP analyzed genetic diversity of8Oenococcus oeni,9Lactobacillusbrevis,9Lactobacillus mali and17Lactobacillus plantarum.The result showed that amongthe various species of lactic acid bacteria, the PCR products of primers A amplificationpolymorphism is best, and able to achieve the distinction of the strain level, so the method canbe used as the lactic acid bacteria strains of the genetic diversity identified.3: Using RAPD vivificated acid resistance gene tests: molecular test results showed that8O.oeni containing1400bp resistance bands, which strain Me3a had650bp resistance bandstoo;3O.oeni containing2500bp sensitivity gene bands; after biochemical validation test weknew that acid tolerance of resistant strains was slightly higher than the acid-sensitive strains,and the tolerant ability of Me3a was better than the other several strains of bacteria, in linewith the acid resistance gene classification; molecular identification results of Lactobacilluswere different with the results of biochemical tests. Therefore, the acid resistance gene in theLactobacillus also needs to re-screen.