基于16S rRNA基因的7种乳酸杆菌的分子系统发生

对7种乳酸菌的16SrRNA基因的部分序列进行了PCR扩增和序列测定,进行序列比对后,以清酒乳杆菌为外组群,运用MEGA2.0和Tree-Przz5.0遗传分析软件以邻接法(NJ)、最大简约法(MP)和最大似然法(ML)构建系统发生树。结果表明:4种乳酸菌(类干酪乳杆菌、干酪乳杆菌、鼠李糖乳杆菌、戊糖乳杆菌)为一支系,另外3种(类植物乳杆菌、弯曲乳杆菌、草乳杆菌)构成另一支系,这两个支系又互为姊妹群。结果还显示,乳酸菌高级分类单元(超科及以上分类阶元)的系统发生与现行形态分类体系间存在明显的分歧。

The molecular phylogeny of lactic acid bacteria based on partial 16S rRNA gene sequences

The partial sequence of 16S rRNA gene from seven species of lactic acid bacteria commonly found in wine were amplified through the poly merase chain reaction(PCR)and the PCR products were sequenced directly with ABI-377 DNA automatic sequencer.L sake as an outgroup.and we constructed that their molecular phylogenetic trees with neighbour-joining (NJ)、maximum parsimony(MP)and maximum likelihood(ML)methods using MEGA(Version 2.0)and Tree-Puzzle(Version 5.0) software.The results showed that the four species of lactic acid bacteria(L.paracasei,L.casei,L.rhamrgosus,L.pentosus) constituted a monophyletic group;another three species of lactic acid bacteria (L.paraplantarum,L.cutvatus,L.graminis)also made up a polyphyletic group.Furthermore,the two sister groups were monophyletic.That the molecular phylogenies of the higher taxonomic groups(above superfamily)were mostly in conflict with the morphological ones was also showed by the results.