粉粒氨氮和水分影响浮霉菌门群落的空间分化

Effects of silt particles, ammonia nitrogen and water content on structural and functional differentiation of Plantomycetes communities

摘要:

【背景】来自浮霉菌门(Planctomycetes)的厌氧氨氧化菌是高氨污染系统安全脱氮的生态友好型微生物，但关于特定生态梯度下Planctomycetes群落结构功能的空间分化以及驱动分化的主要环境因子等问题尚未引起关注。【目的】阐明Planctomycetes群落结构空间分化及影响其分化的主要环境因子。【方法】运用16S rRNA基因高通量测序手段检测温带半干旱区河流系统砂质及粉质沉积物、粉砂质及粉质土壤Planctomycetes群落结构的空间分布变化，统计学方法分析粉粒等理化因子对Planctomycetes群落结构功能分化的影响。【结果】OM190_ub_o_o. o1种群主要分布在寡营养的砂质沉积物中，仅由砂粒正向驱动；OM190_o_o_o. o2和SM1A02. ub5种群主要分布在中营养的粉砂质土壤中，由水分和pH等正向驱动；AKYG587. ub3、Pla4_lineage_o_o_o. o6、Singulisphaera o7、Singulisphaera ub8、Planctomycetaceae_u. ub9种群主要分布在全营养粉质土壤中，由黏粒、粉粒、盐度、有机碳、全氮、全磷、硝态氮正向驱动；Phycisphaera ub4种群虽优先分布在中营养的粉砂质土壤中，但表现出由中营养向全营养过渡的分布趋势，由硝态氮负向驱动；全部种群都由氨氮负向驱动。变异分析表明粉粒、氨氮、水分贡献了Planctomycetes群落结构变化52.7%、10.4%、10.3%的变异度。【结论】温带半干旱区河流系统Planctomycetes群落存在明显的空间分化特征，沉积物/土壤粉粒、氨氮和水分是驱动Planctomycetes群落结构及功能变异的主要因子，全营养粉质土壤中的Planctomycetes群落可能为附着型异养反硝化菌，寡营养粉砂质土壤中的Planctomycetes群落可能为对氨氮及硝态氮有高度亲和力的游离型自养氨氧化或反硝化菌，这为氨氧化或反硝化相关Planctomycetes群落高效应用于高氨等污染系统的生物脱氮提供了科学依据。

关键词:温带半干旱区，河流系统，Planctomycetes群落，结构和功能分化，主要环境因子

Abstract:

[Background] Anaerobic ammonium oxidation (anammox) bacteria, members of the phylum Planctomycetes, which drive effective N-removal of high concentration ammonia from municipal or industrial wastewater, are designated as eco-friendly microorganisms. However, the structural and functional differentiation of Planctomycetes communities across space and the main environmental drivers have not been paid much attention. [Objective] To elucidate the spatial differentiation of Planctomycetes community structure and the main environmental factors driving associated anammox or denitrification. [Methods] 16S rRNA gene high-throughput sequencing was used to detect the spatial distribution changes of Planctomycetes community structure in sandy or silty sediments/soils of river ecosystem from the temperate semi-arid region. Meanwhile, statistical method was used to analyze the effect of physicochemical factors such as silt particles and water content on the structural differentiation of Planctomycetes communities. [Results] OM190_ub_o_o. o1 population was mainly distributed in oligotrophic sandy sediments, only positively driven by sand particles. OM190_o_o_o. o2 and SM1A02. ub5 populations were mainly distributed in mesotrophic silty-sandy soils, positively driven by water content and pH, etc. AKYG587. ub3, Pla4_lineage_o_o_o. o6, Singulisphaera o7, Singulisphaera ub8 and Planctomycetaceae_u. ub9 populations were mainly distributed in copiotrophic silty soils, positively driven by the clay and silt particles, salinity, organic carbon, total nitrogen, total phosphorus and nitrate nitrogen. Although Phycisphaera ub4 population was preferentially distributed in mesotrophic silty-sandy soils, it displayed a tendency from mesotrophs to copiotrophs, negatively driven by nitrate nitrogen. The entire populations were negatively driven by ammonia nitrogen. Variation partitioning analysis showed that silt particles, ammonia nitrogen, water content contributed to the spatial variation of Planctomycetes communities with 52.7%, 10.4%, 10.3%, respectively. [Conclusion] Planctomycetes communities of river ecosystem in temperate semiarid showed obvious spatial differentiation characteristics, mainly driven by soil/sediment silt particles, ammonia nitrogen and water content. Planctomycetes communities in copiotrophic silty soil might be particle-attached heterotrophic denitrifying bacteria, while Planctomycetes communities in oligotrophic silty soils might be free-living autotrophic ammonia oxidizing or denitrifying bacteria with high affinity for ammonia nitrogen and nitrate nitrogen, respectively. This study provides a scientific basis for the efficient application of ammonia oxidizing bacteria and denitrifying bacteria associated with Planctomycetes to biological removal of high concentration ammonia from polluted systems.

Key words:Temperate semi-arid region, River ecosystem, Planctomycetes community, Structural and functional differentiation, Main environmental factors