从油田分离的两株嗜热产孢子硫酸盐还原菌系统进化分析

PHYLOGENETIC ANALYSIS OF SPORE-FORMING THERMOPHILIC SULFATE-REDUCING BACTERIA FROM OIL FIELD

为了寻找极端微生物资源,将来自油田环境的微生物作为研究对象,分离得到两株硫酸盐还原菌.菌株CW02来自于油田联合污水处理站里的地面污水,兼性厌氧,能在pH为2.8的酸性培养基中生长,耐受最高矿化度为30.0g/L,最高生长温度为48℃,可利用苯环化合物为唯一碳源生长.菌株CW03取自于4000多米深原油井的原油分离水中,严格厌氧,不耐酸,能够在68℃的温度下生长,可利用较短碳链的有机化合物.两株菌都是直或弯的杆状,革兰氏阳性,有极生鞭毛,产孢子.通过16SrDNA测序以及在线的Blast系列比对分析:两株菌均属于细菌界(Bacteria),厚壁菌门(Firmicutes),梭菌纲(Clostridia),梭菌目(Clostridiales),蛋白胨链球菌科Peptococcaceae,脱硫肠状菌属(Desulfotomaculum),与该属中的种Desulfotomaculumnigrificans和Desulfotomaculumaeronauticumd相似性达到98%.但是通过多重序列比对构建进化树的方法分析发现,菌株CW03属于古细菌界,与古细菌界的古生球菌属进化距离较近.

Two strains of spore-forming, thermophilic, sulfate-reducing bacteria were isolated from oil field in order to obtain extreme microorganisms. Strain CW-02 was isolated from ground sewerage of oil field. It is facultatively anaerobic with optimal pH of 2.8 and maximum temperature at 48℃. The optimum NaCl concentration for its growth is 30.0 g/L. CW-03 was isolated from crude oil well of more than 4 000 m deep. It is strictly anaerobic and not aciduric with maximum temperature of 68℃. , and it can use the organic compounds with relatively short carbon chains as electron donors. The two strains are non-motile, curved rod, Gram-positive and spore-forming with polar flagella. The analysis of the 16S rDNA sequence indicated that the two strains, CW-02 （accession numbers： AY703031 ） and CW-03 （accession numbers： AY703031 ） belonged to the genus Desulfotomaculum （Peptococcaceae, Clostridiales, Clostridia, Firmicutes, Bacteria）, and their similarity with D. nigrificans and D. aeronauticumd was 98%. However, by means of multiple sequence alignments CW-03 belongs to Archaea and it is close to Archaeoglobus. Fig 5, Tab 2, Ref 32