Mineral Weathering And Phylogenetic Relationship Of Mineral Weathering Bacteria From Different Habitats In Potassium Mine

Bacteria are the most widely distributed species on the planet, they can participate in a variety of geochemical processes, such as mineral weathering and soil forming. In this study, we discuss the ability of mineral weathering bacteria and their phylogenetic relationship in different habitats of potassium mine, Thus we provide theoretical basis for the interaction between bacteria and minerals, deepen the understanding of the interaction among people, and provide a rich resource for the study of mineral weathering bacteria.In our research, Different level of weathered samples and root, rhizosphere and non-rhizosphere soil of Deyeuxia were collected from the potassium mine in Nanjing, Jiangsu Province. By conventional plate culture method,383 bacteria (237 strains from the weathered rocks and 146 strains from the Deyeuxia samples)were isolated from seven samples of the two habitats. According to mineral weathering experiment, the ratios of the potash feldspar weathering bacteria and biotite weathering bacteria from four different weathered samples were 55.1%-78.26% and 71.43%-87.72%; The ratios of the potash feldspar weathering bacteria and biotite weathering bacteria from Deyeuxia's samples were 79.31%-85.42% and 80%-93.1%, so the strains from samples of Deyeuxia are stronger in mineral weathering. In order to further study the interaction of mineral and bacteria, dynamic simulation experiment of mineral weathering was carried out, three strain was selected from three different samples, these strain have a good ability to weather potassium feldspar. The experiment showed that relative poor nutritional BHM medium are contribute to bacterial to weather potassium feldspar. Fe, Si and Al release were increased by 1.48-2.44, 1.41-1.89 and 1.30-2.47 fold compared to the strains under YN medium, respectively, in the presence of the strains under BHM medium. In the process of test, the elements (Fe, Si, Al and Ca element) which Bacteria need little are constantly release, although the release rate is declining; other elements (K, Mg, and Na element) which Bacteria need much, their release process is very different from the above four elements, It shows that release pattern of elements is different.The strains which had the ability to weather potassium feldspar and biotite were identificated.16S rRNA gene sequence analysis showed that 240 bacteria can be attributed to 22 genera and 56 species. Among them, the bacteria in the bare place attributed to 13 genera and 26 species; the bacteria from Deyeuxia's sample attributed to 17 genera and 42 species. Therefore, whether in the level of genus, or the level of species, mineral weathering bacterial diversity of two habitats exists obvious difference. Bacillus exist in all of the samples, at the same time, It is in dominant position in all the samples. In the level of species, Bacillus cereus exist in all of the samples. In addition, Luteibacter?Mucilaginibacter?Lysinibacillus and Ochrobactrum were specific to different level of weathered samples, Ralstonia? Brevibacillus?Novosphingobium and Curtobacterium were specific to samples of Deyeuxia.The taxonomic status of strain Z29 was studied. Comparative 16S rRNA gene sequence analysis showed that strain Z29 T was most closely related to members of the genus Chitinophaga. The 16S rRNA gene sequence of strain Z29 T showed similarities of 97.9%,98.2%,98.2%, and 97.2% with those of C. polysaccharea KACC 17184T, C. arvensicola JCM 2836T, C. ginsengisegetis LMG 23601T, and C. niastensis JCM 15441T, respectively. The main fatty acids of strain Z29T were iso-C15:0, C16:0, iso-C13:0 and iso-C17:0. It also contained menaquinone 7 (MK-7) as the major respiratory quinone and homospermidine as the main polyamine. The polar lipid profile contained phosphatidylethanolamine, unknown aminolipids, unknown phospholipids, and unknown glycolipids. The total DNA G+C content of strain Z29T was 51.3 mol%. The low level of DNA-DNA relatedness (ranging from 14.6% to 29.8%) to other species of the genus Chitinophaga and the many phenotypic properties demonstrated that strain Z29T should represent a novel species of the genus Chitinophaga, for which the name Chitinophaga longshanensis sp. nov. is proposed.