A Study On The Diversity Of Thermophilic Anaerobic Bacteria From Geothermal Regions In Tengchong Of Yunnan And Qucai Of Tibet

Yunnan and Tibet are two important geothermal areas, which have a wealth of microbial resources. The research about them will not only contribute the development and utilization of thermophilic bacteria, but can also get important information about the generation and evolution. Cuttently, thermophilic bacteria have been studied deeply in the culture-dependent and culture-independent methods, but the study of thermophilic anaerobic bacteria are still very scare.The technique about isolation and cultivation of the anaerobic bacteria from hot spring samples had been tried and optimized in this thesis, and finally, we got a reliable technology roadmap for the isolation and cultivation of the thermophilic anaerobic bacteria, and the diversity of cultured thermophilic anaerobic bacteria from hot springs in Rehai and Ruidian sites of Tengchong of Yunnan, Qucai site of Tibet, was studied using this pure culture technique. Total51strains were obtained from the hot springs mentioned above using plate separation techniques. All of them were selected for analysis of their16S rRNA gene sequences, and besed on the results, their taxonomic status were determined, the phylogenetic analysis showed that they belonged to the members of13different genera: Anoxybacillus (9strains), Bacillus (15strains), Carboxydocella (1strain), Clostridium (4strains), Effusibacillus (2strains), Enterococcus (1strain), Garciella (1strain), Tepidimonas (1strain), Thermoanaerobacterium (5strains), Thermoactinomyces (1strain), Thermomonas (1strain), Thermobrachium (3strains) and Caloramator (7strains). Members of genera Anoxybacillus and Bacillus were found widely distributed in hot springs. The majority of the isolated strains were the known species that have been published previously. However,7strains of them were shown to have lower16S rRNA gene sequence similarities with the other deseribed anaerobes (93.26-98.45%), phylogenetic analysis showed that these strains are potential new taxa. The morphology charaeteristics, physiologieal and biochemieal charaeteristics, chemotaxonomic data and16S rRNA gene sequence phylogenetic analysis of two candidates were studied, their taxonomic status were determined. The results showed the strain YIM G1-1T represent a novel species of genus Garcilla, of which the name Garcilla tengchongensis sp. nov. is proposed, and the strain YIM A1-8T represent a novel species of genus Clostridium, of which the name Clostridium tengchongensis sp. nov. is proposed.The strains isolated in this study could enrich the resource of thermophilic anaerobes, and would be beneficial to furher study of their diversity, distribution among different regions and application.