SSCP技术解析硫酸盐还原反应器中微生物群落结构

采用改进的单链构象多态性(SSCP)技术,以16SrRNA基因的V3区为靶对象,分析完全混合式硫酸盐还原反应器中微生物的群落结构以及硫酸盐还原菌(SRBs)与产酸菌(ABs)的种间关系.共得到13个可辨晰的SSCP条带,对其中的6条带(A1,A3,A4,A5,A9,A10)进行了测序分析,分别同嗜柠檬酸明串球菌(GenBank登录号:AY453065,下同)、未培养细菌(AJ318147,AF227834,AJ576427)、产乙醇杆菌(AY434722)、梭杆菌(AB084627)等相似性较大.为检测系统中的SRBs,以SRBs富集培养基,对反应器中的活性污泥进行选择性富集,培养的混合菌群同样采用SSCP分析,带型与前者相差较大,其中有2条带与Bacteroidetes(AB074606)和脱硫弧菌(Y12254,U42221)最为相似.分析表明,SRBs在总DNA中的含量可能不到1·5%,但是它们与大量的ABs形成很好的种间协作关系,从而维持工艺系统较高的硫酸盐去除率和运行稳定性.

Microbial Community Structure Analyzed by Single-Strand Conformation Polymorphism Technique in Sulfate-Reducing Reactor

Analyses of microbial community structure and the relationships between Sulfate-Reducing Bacteria (SRBs) and Acidogenic Bacteria (ABs) in a completely stirred sulfate-reducing reactor were carried out by modified polymerase chain reaction-single-stranded conformation polymorphism (PCR-SSCP) targeted eubacterial 16S ribosomal RNA gene. A total of 13 bands were obtained and 6 of them (A1, A3, A4, A5, A9, A10) were sequenced. The sequences are similar to Leuconostoc mesenteroides (GenBank Access No.AY453065), some uncultured bacteria (AJ318147, AF227834, AJ576427), Ethanologenbacterium (AY434722), Clostridiaceae (AB084627), etc. In order to investigate the SRBs in the reactor,the active sludge was cultured on SRB-selected media and also did SSCP with the compound cultured bacteria. Two new bands appeared, one similar to Bacteroidetes (AB074606) and another similar to Desulfovibrio (Y12254, U42221). The experimental results indicate that the proportion of SRBs in the reactor is probably less than 1.5 percent. But the few SRBs play a very important role during the course of sulfate reduction via cooperation with acidogenic bacteria.