Study On The Spatial And Temporal Distribution And Community Structure Of Related Microbial Methane Cycle In The Sediment Of Hun River And Correlation With Its Environmental Factors

To understand the role of river in the cycling of global methane is critical for elucidating the global greenhouse gas budget.C urrently,the research community characteristics most associated microbial methane around the paddy fields,wetlands,lakes and other ecological environment,and for the river is rarely reported.In this study,using PCR-RFLP(restriction fragment length polymorphism polymerase chain reaction)technology and clone library technology and other methods,to investigate of river and sediment,the diversity and community structure of methanogens and N-DAMO and some related environmental factors were analyzed.In addition to the methyl coenzyme M reductase(mcr A),particulate methane monooxygenase(pmo A)and the 16S r RNA genes of N-DAMO were included in the investigation to have a comprehensive understanding of methane cycling microbes.The following conclusions are drawn from the study.(1)There are a lot of uncultured N-DAMO in Hun River sediments.16S r RNA and pmo A gene sequences detects N-DAMO major river,lake and peat sediments,sewage sludge,sediment of underground ecosystems and rice soil as inoculum the resulting culture was enriched highest sequence similarity.Temporal changes in community structure characteristics N-DAMO more obvious diversity susceptible to the surrounding environment.(2)Methanogenic archaea communities in the sediments of Hun River could be divided into four groups,Methanobacteriales,Methanomirobiales,Methanocellales and Methanosarcinales.(3)Community structure of methanogenic archaea indicated spatial variability form upstream to downstream.The sediments of upstream were Methanosarcina and Methanospirillum.Main genera present in the sediments of midstream were Methanosarcina,Methanobacterium and Methanomethylovorans.In the sediments of downstream,main genera present were Methanosarcina and Methanobacterium,All in all,The main genera in sediments of Hun river were Methanosarcina.Main genera present in the sediments of Methanosarcina and Methanobacterium in March and September.(4)In Hun River,the main factors that affected the diversity of community struc ture of N-DAMO were TOC,p H,BOD₅ in water and TN,moisture content,conductivity in sediments;TOC,BOD₅,p H,ammonia nitrogen in water and TN,DOC in sediments contributed to the diversity of community structure of pmo A genes while the key factors that influenced the diversity of community structure of mcr A genes were TOC,TP, nitrite,nitrate nitrogen in water and conductivity,DOC,moisture content in sediments.