Effects Of Environmental Factors On The Soil Microbial Community Structure And Functional Diversity In Typical Areas,China

Soil microorganism plays integral and unique role in decomposition processes,and it affects the material circulation and energy flow.Although size of individual microorganism strain is microscopic,the quantities and types is huge,they are the most important part of ecosystem.The relationship of microbial diversity and environmental factors have become the study focus gradually.China has a vast territory,including diverse micro-domain ecological environments.The black soils in Heilongjiang Province have intimate relationship with human activities of life and production.Meanwhile,the frozen soils are in extreme environment.Therefore,they have become the hot research areas.In order to investigate effects of environmental factors on the soil microbial community structure and functional diversity in these two areas,traditional cultured-based method and 16S rRNA gene sequences phylogenetic analysis used to study the community structure of black soil bacteria,frozen soil bacteria and actinobacteria.The functional diversity discussed with Bio log indentification technology.What’s more,physico-chemical characteristics and microbial biomass carbon combined with the results of microbial diversity.In this study,a total of 157 bacterial strains were obtained in the black soils.The bacterial isolates were affiliated with 3 phyla,7 genera,and 27 species.144 bacterial strains,which affiliated with 4 phyla,10 genera,36 species,obtained in the frozen soil.There are two isolates affiliated with Unclassified Bacillaceae.The 184 frozen soil actinobacteria could be grouped into 5 families,8 genera,and one isolate affiliated with Unclassified Actinomycetales.According to the results of phylogenetic analysis,it found that there have some culturable bacterial and actinobacteria species in both the high-latitude and high-altitude frozen soil areas.However,the community structure of culturable microorganisms are diverse in these two different frozen soil areas.The results of soil microbial functional diversity showed that microbial biomass carbon in the black soils and frozen soils was quite plentiful.The black soil microorganisms have strong carbon source metabolic capacity for different land use types.Functional diversity under different land use patterns was diverse.Microbial carbon functional diversity among different plots in the frozen soil areas has some discrepency.Microbial functional groups in flooded environments are significantly distinguished from non-flooded environment.Our data have implications for a better understanding of culturable bacterial community in the black soils and frozen soils in China.The results provide with the basic information of substances and energy circulation in the microbial decompostion process.It makes people can exploit and protect the precious black soil and frozen soilresources reasonably.