Study Of Bacterial Community Diversity In Oil Reservoir And Systemic Taxonomy Of Novel Species

Objectives:1.Analysis the diversity and structure of bacterial community in oil reservoirs.2.To compare the bacterial community diversity from different oil reservoirs in order to guide individualized microbial oil recovery methods.3.To study the taxonomic status of new species candidates,as well as understanding the characteristic of these novel species.Methods:1.The oil production waters were collected from oil wells head and transported in sterile sealed containers with ice packs.2.The method of 10-fold dilution plating on 10 different isolation media were used to screen strains from these samples.3.Genomic DNA extraction,16S rRNA gene PCR amplification and sequencing were performed to identify phylogenetic relationship of all isolation 4.The polyphasic taxonomy including phylogenetic,physiologic and chemotaxonomic analysis were performed to analyze the taxonomic status of new species candidates.Results:1.Total 440 bacteria strains were isolated from three oil reservoirs.2.These strains belonged to 6 phyla(Firmicutes,Proteobacteria,Actinobacteria,Flavobacteriia,Deinococci,and Bacteroidetes),49genera(mainly,Pseudomonas,Halomonas,Bacillus,Brevundimonas,Streptococcus,Sphingobium,Sanguibacter,and Planomicrobium).3.Based on 16S rRNA gene sequencs,NCBI database comparison and phylogenetic tree construction,17 new species and 1 genus candidates were isolated.4.Compared bacterial community structures from different oil reservoirs,it is concluded that the bacterial community has obvious regional difference.5.Respectively identified the novel strains of SSR2A-4-2~T,SZDIS-1-1~T and SZDIS-1~T and proposed their name as Blastomonas marina sp.nov.,Microbacterium sorbitolivorans sp.nov.,Vibrio gangliei sp.nov..Conclusion:1.The strains from Qinghai,Yumen and Daqing oilfields were significantly different.In the phylogenetic tree,they formed distinct branches and obvious regionality.2.The strains from crude oil mainly contains Pseudomonas and Halomonas,which will helpful to MERO.3.Rich bacterial strains resource enriched the data storage of microbial strains in oil reservoir and provided a broader application prospect in the field of microbial enhance oil recovery and environmental pollution remediation.