藏北地区传统发酵乳中乳杆菌的多样性分析

摘要

[Objective] In order to study the biodiversity of Lactobacilli from Northern Tibet in China, we developed enterobacterial repetitive intergenic consensus sequence polymernse chain reaction (ERIC-PCR) technique. [Methods] Seventy seven Latobacillus strains were isolated from traditional fermented milk products which are made by herd man families in Northern Tibet of China. By ERIC-PCR technique method, using NTSYS-pc2.1 software, we investigated the biodiversity of the strains. [Results] The amplified bands of ERIC-PCR were clear and stable with high repetition and high polymorphisms. The cluster analysis showed that at level 0.73, 77 tested strains were clustered into 4 groups: AI: strains of Lactobacillus casei (35.06% of the strains), A2: strains of Lactobacillus fermentum (61.04% of the strains), A3: strains of Lactobacillus helveticus and A4: strains of Lactobacillus plantarum. The biodiversity of the isolates from Aland A2 groups was further investigated. A1 could be divided into 5 genotypes at the similarity of 80.0%. A2 could be divided into 6 genotypes at the similarity of 84.0%.[Conclusion] Using ERIC-PCR technique, Lactobacilli from Northern Tibet could be distinguished at species level.%[目的]针对藏北地区的乳杆菌来源及种属,对其多态性进行研究.[方法]采用ERIC-PCR技术和NTSYS-pc2.1软件对从藏北地区牧民家庭制作的发酵乳制品中分离出的77株乳杆菌进行多样性分析.[结果]ERIC-PCR扩增出的条带清晰,重复性好,多态性高.聚类分析表明,在0.73的水平上,77株乳杆菌共分为4大类群:干酪乳杆菌群A1、发酵乳杆菌群A2,瑞士乳杆菌群A3和植物乳杆菌群A4.其中,干酪乳杆菌群A1和发酵乳杆菌群A2分别占供试乳杆菌的35.06%和61.04%,为优势菌群.进一步对优势菌群聚类,在0.80的水平上,群A1被分成5个基因型,在0.84的水平上,群A2被分成6个基因型.[结论]从分型结果来看,ERIC-PCR技术可以将不同种属间的乳杆菌区分开,但无法将藏北地区的乳杆菌按地理来源不同或和分离基物不同区分开.