| As a new type of energy, natural gas hydrate is more and more important to the countries. The Qiangtang basin is one of the permafrost region in our country. According to the forecast, there is a lot of natural gas hydrate. So the exploration of Qiangtang basin is urgently needed. The study is a comprehensive analysis of the microbial community and structure of the drilling core samples from permafrost in Qiangtang basin. Culturable dependent method and high-throughput sequencing technology have been applied in the research. At the same time, the relevance between microbial community and the environment are analyzed by combining with the physicochemical properties of drilling cores and the environmental factors. Thus, the study can instruct the project of the exploration of gas hydrate resource from permafrost area of the center of the China geological survey. The details of the study are as follows:1. By culturable dependent method, about 100 bacterium were isolated from the samples. Through 16SrRNA sequence comparison, a novel strain was found. The strain was then given to others of the laboratory to identify. Others were known species and stored in glycerin tube respectively, reserved for other studies.2. Total DNA of the samples were extracted using soil DNA kit (omega), and then high-throughput sequencing technology was used to analyze. The Ion Torrent of the second generation sequencing was used in the study. The structure of the bacterium and the archaea, the a-diversity and the β-diversity were analyzed, and associated with the properties of the drilling cores. The main bacteria groups of QK4 and QK5 were actinobacteria, bacteroidetes, deinococcus-thermus, firmicutes and proteobacteria. The main archaea groups were Crenarchaeota and Euryarchaeota. Between individual samples had a certain similarity and related with the physicochemical properties of drilling cores.3. For a further analysis of the relevance between microbial community and the environment, for each samples, summarized the advantage bacterium groups and their percentage. Then associated with the physicochemical properties of drilling cores, this revealed the relationship between the main microbe groups and the environment. At the same time, we got the headspace gas composition of the samples from the oil and gas resource center. The gas composition had played a important role in the formation of energy. Through related with the microbial diversity, this could indirectly reveal the effect of the microbial diversity to the energy. Then this could instruct the project.4. A bacterium strain, designated Z8T, was isolated from the terrestrial sediment of the Mohe Basin in northeast China. Phylogenetic analyses of 16S rRNA genes showed that this strain belonged to the genus Phyllobacterium and was most closely related to Phyllobacterium bourgognense, which gave sequence similarity of 96.9%. The major cellular fatty acids were summed feature 4 (iso-C17:1 I and/or anteiso-C17:1 B) and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c). The major respiratory quinone was Q10. The three major polar lipids of strain Z8T consist of glycolipids (GL), phosphatidylethanolamine (PE) and phosphatidylmethylethaolamine (PME). It differed from its closest relatives in its growth in diverse culture conditions and in the assimilation of several carbon sources. The DNA G+C content was 59.6 mol%. Based on the phenotypic, phylogenetic and genotypic data, strain Z8T is considered to represent a novel species in the genus Phyllobacterium, for which the name Phyllobacterium sediminis sp. nov. is proposed. |
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