不同年份窖泥细菌16S rDNA系统发育分析

Phylogenetic analysis of bacteria in pit mud of different cellar age

本研究直接提取5、10、20、50年窖泥细菌总DNA,扩增16SrDNA并构建克隆文库后进行系统发育分析.结果表明,随着年份增加,细菌多样性指数呈现出先增加后略有下降最后回升稳定的趋势;198个阳性克隆子划分成43个分类操作单位(OTUs),按优势顺序依次为Firmicutes、Bacteroidetes、Chloroflexi、unclassified Bacteria、Proteobacteria、Tenericutes、Actinobacteria、Planctomycetes和Spirochaetes.不同年份窖泥中优势菌不同,在5、50年窖泥中紫单胞菌科占优势,而在10、20年窖泥中梭菌目占优势.其中Petrimonas、Rikenellaceae、Syntrophomonadaceae、Clostridium、Lactobacillus等细菌均有发现,它们在窖泥老熟和白酒风味物质生成过程中发挥着重要作用.

Total DNA of bacteria in pit muds of cellar ages of 5, 10, 20, 50 years were extracted respec- tively in this study, based on which, the 16S rDNA was amplified, and the gene clone libraries were constructed for phylogenetic analyzing. The results showed that bacterial diversity index rised at the be- ginning, then declined slightly and finally returned to a higher level with the increase of cellar age. A to- tal of 198 positive clones were classified into 43 operational taxonomic units （OTUs） . The order of dominance was as follows： Firrnicutes, Bacteroidetes, Chlorofle：ci, unclassified Bacteria, Proteobacte- ria, Tenericutes, Actinobacteria, Planctomycetes, Spirochaetes. Predominant bacteria varied with the pit muds. Porphyromonadaceae took the role in 5- and 50-year-old pit mud while Clostridiales was pre- dominant in 10-and 20-years samples. Petrirnonas, Rikenellaceae, Syntrophomonadaceae, Clostridiurn and Lactobacillus which played an important role in the mature process of pit muds and the production of flavor substances in Chinese distilled spirit were also disclosed.