羊羔美酒大曲中乳酸菌多样性及分子鉴定

目的:分离和鉴定羊羔美酒大曲中的乳酸菌,探寻其菌群多样性,为酿酒工艺条件改进提供参考。方法:将酒曲进行梯度稀释、富集培养、平板画线等分离纯化,获取乳酸菌单菌落。采用菌落特征和个体形态特征结合的方法进行乳酸菌形态鉴定。乳酸菌的分子鉴定采用重复序列聚合酶链式反应(repetitive sequence-based polymerase chain reaction,Rep-PCR)技术和16S r DNA序列分析法。结果:从羊羔美酒大曲中共得到65株乳酸菌,形态学分为9类。用Rep-PCR技术在75%的相似性上将其区分为5类,经基因序列分析,鉴定为分属于4个属的乳酸菌,分别为:片球菌属(Pediococcus)、明串珠菌属(Leuconostoc)、乳杆菌属(Lactobacillus)、肠球菌属(Enterococcus)。结论:传统微生物分离技术与现代分子鉴定技术相结合,可快速准确鉴定出羊羔美酒大曲中乳酸菌的菌群组成和多样性。

Diversity and Molecular Biological Identification of Lactic Acid Bacteria from Yanggaomeijiu Daqu,a Traditional Chinese Liquor Fermentation Starter

Purpose: The aim of this work was to isolate and identify lactic acid bacteria (LAB) in Yanggaomeijiu Daqu,
a fermentation starter for the production of Chinese liquor Yanggaomeijiu, and to explore the diversity of LAB in
Yanggaomeijiu Daqu. Methods: Individual bacterial colonies of LAB from Yanggaomeijiu Daqu were obtained through
isolation and purification steps including gradient dilution, enrichment, cultivation, and plate streaking. Morphological identification
of LAB isolates was performed based on colony and individual morphological characteristics and further molecular identification
was carried out by repetitive sequence-based polymerase chain reaction (Rep-PCR) and 16S rDNA sequence analysis. Results: A
total of 65 LAB isolates were obtained from Yanggaomeijiu Daqu, which could be assigned into 9 different groups by conventional
microbiological analysis, differentiated into five types by Rep-PCR at a 75% similarity, and belonged to 4 genera including
Pediococcus，Leuconostoc, Lactobacillus and Enterococcus by gene sequencing. Conclusion: The diversity and composition
of LAB in Yanggaomeijiu Daqu can be identified quickly and accurately by the combination of traditional microbial separation
methods and modern molecular biological identification techniques.