藏灵菇发酵乳中醋酸菌的多样性分析

Diversity analysis of acetic acid bacteria isolated from Tibetan kefir dairy

对国内不同地区采集的8份藏灵菇发酵乳样品中醋酸菌进行分离鉴定,通过16S r DNA同源性分析和系统发育树分析来探究藏灵菇中醋酸菌的组成和遗传多样性。结果表明,共分离得到44株醋杆菌,分别为Acetobacter fabarum(20株)、Acetobacter orientalis(5株)和Acetobacter syzygii(19株);Acetobacter fabarum和Acetobacter syzygii为藏灵菇发酵乳中的优势醋杆菌,且二者亲缘关系较近。序列分析显示Acetobacter fabarum菌株表现出良好的稳定性;而在Acetobacter syzygii中,共发现4个变异位点,在系统发育树中进化程度高;在Acetobacter orientalis中,共发现5个变异位点。

Acetic acid bacteria from the eight samples of Tibetan kefir dairy,which collected from different regions in China were isolated and identified by 16S rDNA sequence analysis and phylogenetic tree analysis, aimed to explore the acetobacter composition and genetic diversity in Tibetan kefir.The results of the identification included Acetobacterfabarum （20 strains）, Acetobacter orientalis （5 strains） and Acetobacter syzygii （19 strains）. Acetobacterfabarum and Acetobacter syzygii, which hadclose relationship, were themain Acetobacter in Tibetan kefir dairy. Sequence analysis shown that Acetobacterfabarum has a good characteristic of stability. Four mutations were tested and the strains with mutations had highdegreeof evolution in Acetobacter syzygii. In addition, 5 mutations were tested inAcetobacter orientalis.