8株光合细菌的鉴定及其系统进化关系分析

目的为8株光合细菌(photosynthetic bacteria,PSB)作为益生菌株提供系统资料。方法用常规方法对8株PSB菌株的形态、培养特性及生理生化特征进行鉴定,同时定性分析菌株产生的类胡萝卜素和CoQ,测定菌株16S DNA序列并分析其系统进化关系,在GenBank中获取了8个16S DNA序列号。结果菌株鉴定结果表明:菌株2C、2c和13ing为沼泽红假单胞菌,Ga、Il106、WS8N为类球红细菌,MT1131为荚膜红细菌,rub为深红红螺菌。基于菌株16S DNA序列的系统进化树显示,同一种菌并不总是聚为一簇,但相隔较近;种属完全不同的菌株,尽管序列相似性高达97%以上,在系统进化树上相隔较远。结论8株PSB菌株的鉴定和系统进化关系分析结果为后续研究提供了背景资料,同时菌株在GenBank中获得的16S DNA序列号为菌株作上了生物标记,也为菌株的产权保护提供了依据。

Identification of 8 photosynthetic bacteria strains and analysis of their phylogenetic relation

Objective To provide systematic data for photosynthetic bacteria as potential probiotics.Method The morphologic and cultural properties along with the physiologic and biochemical characteristics of 8 Photosynthetic bacteria（PSB） were analyzed.The carotenoids and Coenzyme Q produced by the strains were also analyzed qualitatively.The 16S DNA sequences and their phylogenetic relation were analyzed too;Accession numbers of the strains′ 16S DNA sequences in GenBank were also acquired.Result The identification of the strains showed that strain 2C,2c and 13ing were Rhodopseudomonas palusris,while Strain Ga,Il106 and WS8N were Rhodobacter sphaeroides;Strain MT1131 was Rhodobacter capsulatus;Strain rub was Rhodospirilum rubrum.The phylogenetic relation analysis based on their 16S DNA sequences showed the same species did not always gather into a cluster,but were rather closer.Although the similarity of their sequences were as high as above 97% the strains belonged to different genus and species.Conclusion The results of identification and phylogenetic relation analysis of the strains provide background data for further research.At the same time the accession numbers of the 16S DNA sequences of the strains acquired in GenBank afforded bio-mark and basis for intellectual property protection for the strains.