Analysis Of Anaerobic Methane Oxidizing Bacteria Community And Influencing Factors In Sediments Of Ulansuhai

Ulansuhai lake is located on the Inner Mongolia Plateau and lies at the boundary between cold and arid regions and the lake is the natural habitat of this study.Nitrite-dependent anaerobic methane oxidation(N-DAMO)process and its functional microorganisms have been rarely studied in this natural habitat type.N-DAMO bacteria is the participant in denitrifying metabolic pathway and methane oxidation metabolic pathway.Important function of this bacterium are reduce water eutrophication and reduce methane emission fluxes in lake ecosystem.In this study N-DAMO bacteria were studied in the lake ecosystem of Ulansuhai.The environmental factors of nutrients and survival factors in the sediments of Ulansuhai were obtained by means of in-situ measurement and laboratory analysis.Using molecular cloning technique,quantitative fluorescence PCR and high-throughput sequencing of amplicons,we revealed the composition of N-DAMO bacterial community and the absolute quantitative abundance data of functional microorganisms in the sediments of Ulansuhai.In addition,the absolute quantitative abundance data of N-DAMO bacterial community composition and related functional microorganisms in the sediments of Ulansuhai were obtained.In this study,the coupling relationship between environmental and biological factors with N-DAMO bacterial community was explored by Pearson correlation analysis and RDA analysis.The following conclusions are drawn from this study:The absolute abundance of N-DAMO bacteria from 1.72×10⁴?5.75×10⁵(copies·g^-1) in the sediments of Ulansuhai.The abundance of N-DAMO bacteria in the surface sediments is higher than that in the subsurface and deep sediments,and is lower in the S202 and S204 sampling points.Sampling site S204 had higher bacterial community diversity,richness and evenness.The diversity,richness and evenness of the bacterial community increased with increasing depth.The environmental factors in the sediments of Ulansuhai show horizontal and vertical spatial heterogeneity to a certain extent.The contents of total carbon and available phosphorus were positively correlated with the absolute abundance of N-DAMO bacteria,but the increase of Total Carbon content significantly decreased the community richness.Appropriate p H value is beneficial to the improvement of the diversity and richness of the bacterial community.The increase of the total depth from the sample to the water surface significantly improved the evenness of the bacterial community.Genus SH765B-TZT-35 was the dominant genus in the Ulansuhai,with the highest proportion of relative abundance in the N-DAMO bacterial community composition.This genus showed strong adaptability to the environment.The absolute abundances of pmoA,amoA,nirS,and nirK gene in the surface sediments of Ulansuhai were relatively high,while the abundance of mcr A gene and total archaea 16S rRNA gene were high in the deep sediments.The abundance of nirS,nirK and total bacteria 16S rRNA gene were positively correlated with the bacterial abundance of N-DAMO,but the increase of pmo A,nir S and nir K gene abundance would lead to a significant decrease in the diversity and richness of N-DAMO bacterial community.The increase of total archaea was beneficial to the improvement of the diversity and richness of N-DAMO bacterial community.