鄱阳湖湿地细菌群落多样性和可培养细菌功能基因丰度

Bacterial Community Diversity and Functional Gene Abundance of Culturable Bacteria in the Wetland of Poyang Lake

鄱阳湖湿地中蕴含着丰富的微生物资源,参与并维持着湿地生态系统的物质循环和稳定.为探明鄱阳湖湿地土壤细菌分布规律,分析可培养细菌群落结构和功能特征,采用Illumina MiSeq高通量测序技术分析了鄱阳湖湿地土壤全部细菌(AW)和湿地外围周边土壤全部细菌(AS)群落结构多样性特征;又结合可培养方法和qPCR功能基因芯片技术,分析了湿地可培养细菌(CW)和湿地外围周边土壤可培养细菌(CS)功能基因丰度差异.研究发现鄱阳湖湿地土壤细菌多样性低于湿地外围周边土壤细菌,变形菌门和酸杆菌门是两种土壤环境中共有的细菌优势菌门,放线菌门、厚壁菌门、绿弯菌门和热脱硫杆菌门也是存在于两种土壤中的主要菌门,但相对丰度均差异显著;网络分析显示湿地土壤较周边土壤细菌网络结构更简单.采用可培养方法获得的不同采样点土壤细菌群落多样性差异不明显.但湿地土壤可培养细菌功能基因的拷贝数高于周边土壤,其中参与氮循环的UreC基因和参与碳固定的acsE基因在两种土壤可培养细菌中相对丰度较高.研究结果可为深入挖掘调控、维持湿地土壤养分循环和促进鄱阳湖湿地生态系统功能稳定性的潜在有益微生物提供理论依据.

The microbial communities in the wetland of Poyang Lake are complex and diverse and participate in and maintain the material cycle and stability of the wetland ecosystem.In order to investigate the distribution pattern of the soil bacterial community and analyze the community structure and function characteristics of culturable bacteria,we analyzed the community structure characteristics of all soil bacteria and compared the differences between those in wetland soil(AW)and those in the periphery of the wetland soil(AS)using Illumina MiSeq high-throughput sequencing technology.We also analyzed the characteristics of functional genes of the culturable bacteria in wetland soil(CW)and culturable bacteria in the periphery of the wetland soil(CS)using the traditional culturable method and qPCR functional gene chip technology.The results showed that the diversity of soil bacteria in the wetland of Poyang Lake soil was lower than that of soil bacteria in the periphery of the wetland soil,and Proteobacteria and Acidobacter were the dominant bacterial phyla in both soil environments.Actinobacteriota,Firmicutes,Chloroflexi,and Desulfobacterota were the main bacterial phyla,but their relative abundance varied significantly.The results of network structure abundance revealed that the bacterial network of wetland soil was simpler than that of the external environmental.Differences in the diversity of bacterial communities obtained were not significant at different sites.The copy numbers of functional genes of the culturable bacteria in wetland soil were higher than that in the periphery of the wetland soil.The UreC gene involved in nitrogen cycling and the acsE gene involved in the carbon fixation process were more abundant in the culturable bacteria of the wetland soil and surrounding soil.The results of this study provided a theoretical basis for further excavation of beneficial microorganisms that can regulate and maintain nutrient cycling in wetland soils and promote the functional stability of the Poyang Lake wetland ecosystem.