从22份西藏地区传统发酵奶制品中分离到113株乳酸菌,16S rDNA鉴定结果显示它们分属于6个属,包括乳杆菌属、链球菌属、明串珠菌属、肠球菌属、乳球菌属和芽孢杆菌属.其中乳杆菌属有12个种,德氏乳杆菌保加利亚亚种和发酵乳杆菌为优势菌种,另外还包括到1株格氏乳杆菌和1株卷曲乳杆菌.采用菌落拉丝并结合检测胞外多糖产量的方法,筛选到16株乳酸菌可在脱脂乳中产生胞外多糖.挑取其中产量较高的3株进行发酵性能测试,发现菌株德氏乳杆菌保加利亚亚种1 576的产酸速率适中、后酸化稳定,并能形成质构稠厚的发酵乳.%113 Lactic acid bacteria (LAB) strains were isolated from 22 traditional dairy products in tibet,China,and 6 genus namely,Lactobacillus,Streptococcus,Leuconostoc,Enterococcus,Lactococcus and Bacillus were identified by the method of 16S rDNA blast.In the Lactobacillus,12 species were identified and Lactobacillus delbrueckii subsp.lactis was the predominant strain.In addition,one strain of Lb.gasseri and one strain of Lb.cripatus were isolated in the genus Lactobacillus.16 LAB strains produced exopolysaccharides in slim milk and 3 strains with higher production were picked to determine fermenting properties.Results showed that Lb.delbrueckii subsp.lactis 1576 was a better starter stain with moderate rate acid producing,stable post-acidification and viscous texture.
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