The Polyphasic Taxonomy Study Of Paenibacillus Ferrarius Sp. Nov. And The Preliminary Study Of The Bacterial Diversity In Iron And Selenium Mineral Soil

Microbes are varied and widely distributed in nature. However, only a small fraction of microbes are known so far. Thus, the classification and identification of microbes are necessary and those work have great impacts for biological resources and human production application.In order to explor the microbial community structure of iron mineral soil, 66 strains were isolated from the iron mineral soil of Zhang Jiajie Mountain, Hunan Province, China. According to the 16 S r RNA gene sequence analysis, those strains mainly distributed in 27 species, 8 genera of Burkholderia, Paenibacillus, Arthrobacter, Bacillus, Streptomyces, Lysinbacillus, Dyella and Leifsonnia. The predominant genera were Burkholderia and Paenibacillus.16S r RNA gene sequence homology analysis showed that a strain CY1^T was most closely related to Paenibacillus chondroitinus DSM 5051^T（97.7% 16 S r RNA gene sequence similarity）, Paenibacillus pocheonensis KCTC 13941^T（97.4%） and Paenibacillus frigoriresistens JCM 18141^T（97.0%）, respectively. The DNA-DNA hybridization dissociation values were lower than 49% with the most closely related species, which indicated that strain CY1^T was likely to be a novel species of the genus Paenibacillus. Therefore this study attempted to determine the classification status of strain CY1^T by polyphasic taxonomic methods.Strain CY1^T was Gram-reaction-positive, strictly aerobic, rods and endosporeforming rods with peritrichous flagella. Colonies on NA medium were yellowish to creamy-white, round, medium size, smooth, flat, opaque after incubation for 2 d. The growth temperature range of Strain CY1^T was 4 to 37 ° C（optimal at 28 ° C）, growth p H range was 5.0 to 8.0（optimal at p H 6.0-7.0）. Growth occurs with 0-1.5% Na Cl（optimal at 0%）. Positive result for oxidase and catalase activities, hydrolysis of Tween 80 and aesculin and production of NH3 and H2 S, but negative for nitrate reduction, citrate utilization, methyl red and Voges-Proskauer tests, egg yolk reaction, production of indole, and hydrolysis of starch, gelatin, casein, urea, L-tyrosine, arginine, Tween 20, DNA and CM-cellulose. The major fatty acids（5%） were anteiso-C_15:0（63.4%）, isoC_16:0（11.7%）, iso-C_15:0（6.8%） and C_16:0（5.8%）. The predominant respiratory quinone was MK-7. The main polar lipids were diphosphatidylglycerol（DPG）, phosphatidylglycerol（PG） and phosphatidylethanolamine（PE）. The diagnostic diamino acid of the cell-wall peptidoglycan was A1γ-meso-diaminopimelic. The genomic DNA G+C content was 50.5 mol%. According to the phylogenetic, chemotaxonomic and biochemical data, show that strain CY1^T represents a novel species of the genus paenibacillus, and was named Paenibacillus ferrarius sp. nov. Strain CY1^T was deposited to Korean Collection for Type Culture and China Center for Type Culture Collection, under the number KCTC 33419 and CCTCC AB 2013369.Paenibacillus was used widely in plant disease control and environational pollution control. In order to explore the distribution characteristics of Paenibacillus in mineral soil, this study analyzed the bacterial diversity in the soil of iron and selenium mineral soil samples which collected by our research group. Then I discovered Paenibacillus have a certain distribution in those samples, and in some of the samples genus Paenibacillus was dominant species. This study enriched the diversity of genus Paenibacillus, and provided the material resources and experimental data for follow-up study of the characteristics and application value of Paenibacillus.In addition to the above results, I myself also participated in the research of bacterial arsenite-oxidation regulated by the phosphate two-component system Pho BR in Halomonas sp. HAL1 and the comparative genomic analysis of Aremomonas. I engaged in a series of molecular biology and proteomics techiques, including protein expression system construction, expression and purification of proteins, electrophoretic mobility shift assay experiment（EMSA）, DNA footprinting and detection of gene expression by quantitative lac Z reporter. The results have been published in Frontiers in Microbiology and Standands in Genomic Sciences（these parts are not shown in the thesis, but shown in the supplemented materials）.