酱香型大曲细菌的多样性

Research on bacterial diversity of Maotai-flavor Daqu

以酱香型大曲为研究对象,研究酱香型大曲细菌种群多样性及功能基因预测。分别采用可培养稀释平板法以及高通量测序方法分析大曲细菌群落组成,并结合功能基因筛选及高通量测序分析等宏基因组学研究手段,预测其相关基因功能。大曲细菌总数范围在106~108CFU/g,可培养法分离到的51株Bacillus sp.,1株Acinetobacter sp.。确定酱香型大曲细菌的主体类群组成为以厚壁菌门(87.3%~91.8%)为主要类群,其次是放线菌门(3.3%~9.1%),并发现了未曾报道过的蓝细菌门Cyanobacteria(0.1%~1.5%)。确定了以Thermoactinomyces sp.和Bacillus sp.为主的酱香型大曲细菌群落结构组成,其相对含量占细菌总量的60%以上。通过第二代高通量测序方法还对大曲样品中细菌的代谢功能基因进行了预测。

In this study, we investigated the bacterial diversity and functional genes prediction of the Maotai-fla- vor Daqu samples. The bacterial diversities in three kinds of Maotai-flavor Daqu samples were analyzed via the dilu- tion-plate method and high-throughput sequencing method. The results showed that the total number of bacteria colo- nies was in the range of 10^6 -10^8 CFU/g, and a total of 51 strains of Bacillus sp. and only 1 strain of Acinetobacter sp. were identified by the dilution-plate method. Meanwhile, Firmicutes （87.3% -91.8% ） were demonstrated to be the dominant bacterial phylum in the three Maotai-flavor Daqu samples via the high-throughput sequencing method. Intriguingly, Cyanobacteria （0. 1% -1.5% ） were firstly identified in this study. Moreover, Thermoactinomyces sp. and Bacillus sp. , with the relatively abundances 〉60% , were also demonstrated to be the dominant bacterial genera in the three Maotai-flavor Daqu samples. Furthermore, the metabolic functional genes prediction was also investigated via the high-throughput sequencing method.