Diversity Analysis of Lactic Acid Bacteria in Solid-State Fermentation of Duliu Mature Vinegar by Denaturing Gradient Gel Electrophoresis

摘要

PCR-denaturing gradient gel electrophoresis (DG GE) has been already widely used for community structure analysis in various microbial ecosystems. In this study, the presence and diversity of lactic acid bacteria (LAB) in solid-state fermentation of Duliu mature vinegar, a kind of famous Chinese traditional vinegar, were investigated using PCR-DGGE method. Genomic DNA was extracted from 6 vinegar cultures insitu and amplicons of partial 16S rDNA genes were separated by DGGE. The DGGE profile showed that Lactobacillus vaginalis, Lactobacillus aispatus, Lactobacillus panis and Lactobacillus pontis were detected in the whole fermentation process. At the 9th day, Lactobacillus reuteri, Lactobacillus coleohominis, Lactobacillus frumenti, Lactobacillus sp., and two uncultured bacteria gradually disappeared. Non-volatile acids of vinegar cultures were rapidly increased from 0.991 to 1.808 g/100g culture during the first three days and then no remarkable accumulation were observed with the extension of fermentation process, which might be resulted from the decrease of LAB species. Lactobacillus acetotolerans and Lactobacillus helveticus appeared at the 12th and 15th day of acetic acid fermentation, respectively. Duliu mature vinegar has its own unique species, such as Lactobacillus coleohominis, Lactobacillus vaginalis and Lactobacillus helveticus, which had never reported in any other Chinese vinegars. The results revealed that lactic acid bacteria were predominant species in Duliu mature vinegar and played an important role in formation of vinegar flavors.