Study On The Functional Community Structure Of Subgalical Sediments In Tianshan No.1Glacier

Object: Diversity, community structure, distribution patterns of functional microbes at subglacialecosystem were clarified to provide a theoretical basis for understanding the biological basis ofgeochemical processes occurring at the bottom of glacial sediments, as well as provide references for thedevelopment of psychrophile and potential use of biotechnology.Methods: Methods of PCR,16S rRNA and functional genes clone library were used and then bacterialcommunity structure in different samples and phylogenetic relationship of functional microbies mediatednitrogen, sulfur cycle were determined by sequencing, comparative analysis and construction ofphylogenetic trees.Conclusions: Results of our research in Tianshan NO.1glacier as follows:1.16S rRNA clone libraries of different meltwater, surface dust and firn, as well as subglacial sediments inTianshan NO.1glacier indicated that the seven clone libraries respectively included9(TSMW),10(TSD),6(TSBW),10(TSFC),6(TSJW),8(TSX) and16(TSYW) phylum. The common phylum of theselibraries included α-Proteobacteria, β-Proteobacteria, γ-Proteobacteria, Bacteriodates and Actinobacteria,β-Proteobacteria was domain group followed by the Bacteriodates in all the clone librares. Cyanobacteriain TSFC was more abundant than other clone libraries and a sequence of Fibrobacteres was detected onlyin TSBW, one clone related to Desinococcus-Thermus and Gemmatimonadetes were dected in TSD andTSMW respectively. Sulfuricurvum which can carry out nitrate reduction and oxidation of sulfurcompounds was found in TSMW and TSD. Sequence of TSD clone library affiliated to Proteobacteria(55%), Actinobacteria (9%), Gemmatimonadetes (1%), Bacteriodates (35%) and Cyanobacteria (1%), aswell one unclassified bacteria clone (1%). Clones affiliated to the Proteobacteria and CFB phylum weredominant.2. Abundance of archaeal amoA genes was higher than AOB at subgalcial sediments in the Tianshan NO.1Glacier, archaeal amoA clones mainly affiliated to Crenarchaeote and few of them belonged toThaumarchaeota. Except for few clones affiliated to Nitrosospira sp. and Nitrosomonadaceae, the remainclones of bacterial aomA genes were affiliated to unclassified bacterium. In the nifH clone library, majorityof clones blonged to α-Proteobacteria and others were affiliated to β-Proteobacteria, γ-Proteobacteria,-Proteobacteria, Actinobacteria and uncalssifed bacterium. Libraries of nosZ included thirteen genera:Acidovorax, Azospirillum, Hydrogenophaga, Cupriavidus, Alicycliphilus, Leptothrix, Rubrivivax, Azoarcus,Thauera, Thiobacillus, Janthinobacterium, Massilia and Herbaspirillum。3. Apr and soxB genes clone librares at subglacial sediments in Tianshan NO.1Glacier showed that themajority of clones belonged to two genera Thiobacillus and Sulfuricella. In apr clone library, majority ofclones were affiliated to β-Proteobacteria and other groups included α-Proteobacteria, γ-Proteobacteria,δ-Proteobacteria, Nitrospirae, Chlorobi and undefined bacterium. In soxB clone library, β-Proteobacteria were dominant. About the metabolic pathways of these functional microorganisms at subglacial sedimentsin Tianshan NO.1Glacier need to be further explored and studied through metagenomic approaches.