开菲尔粒中一株醋酸菌的分离鉴定

目的]从开菲尔粒中分离并鉴定醋酸菌,为研究醋酸菌在开菲尔饮品发酵及开菲尔粒形成机理提供理论及技术基础。方法]将开菲尔粒粉碎后制备成不同稀释浓度的菌悬液,涂布于筛选培养基上,37℃条件下培养7d,挑选单菌落进行形态观察、生理生化试验,并扩增其16SrRNA基因,测序鉴定。结果]筛选到一株醋酸菌——KAB7。结论]根据该菌形态观察、生理生化试验结果以及16SrRNA测序比对,鉴定为巴氏醋杆菌巴氏亚种。

Isolation and Identification of an Acetobacter Bacteria KAB7 from Kefir Grains

Objective] In order to build the groundwork for researching the fermentation mechanism of kefir and the symbiosis mechanism of the organisms of kefir grains,Acetobacter bacteria was screened and identified from kefir grains.Method] Kefir grains were crushed to pieces and prepared suspensions of these pieces in different concentration,and spread on the screening medium,cultured on 37 ℃ for 7 d,screened the gram negative single colonie and observed its shape and the results of experiments of physiology and biochemistry,PCR amplified its 16S rRNA gene.And the sequence was blasted at NCBI and analysised by MEGA4.Result] An acetobacter bacteria named KAB7 was isolated from kefir grains.Conclusion] It was identified as Acetobacter pasteurianus strain.