重金属污染对不同生境中微生物群落结构的影响

Effects of Heavy Metal Pollution on the Structure of Microbial Communities in Different Habitats

重金属污染严重危害了生态系统中微生物群落的多样性和组成结构,然而目前关于重金属污染对“地表水-沉积物-地下水”这3种生境中微生物群落结构的影响差异知之甚少.以唐河污水库地表水、沉积物和地下水为研究对象,基于16S rRNA高通量测序技术分析对比不同生境下微生物群落多样性和组成差异,揭示了3种栖息地中微生物群落结构的主要驱动因素.结果表明,不同生境中微生物群落的多样性具有显著差异,地下水微生物α多样性显著高于沉积物微生物和地表水微生物;不同生境中的微生物物种组成也具有显著差异,地表水中Pedobacter、Hydrogenophaga、Flavobacterium和Algoriphagus丰度较高,沉积物中Ornatilinea、Longilinea、Thermomarinilinea和Bellilinea等重金属耐受菌占据主要优势,而Arthrobacter、Gallionella和Thiothrix是地下水中的标志性物种;理化因素和重金属变量共同驱动了3种生境中微生物的群落结构变化,pH、 NO_(3)^(-)-N和Li是影响地表水微生物群落结构的主要因素,TP、 NH_(4)^(+)-N、 Cr、 Fe、 Cu和Zn显著影响沉积物中微生物的群落结构,而地下水中微生物群落与pH呈弱相关关系,几乎不受重金属污染的影响.整体上,重金属污染对不同生境微生物群落结构的影响大小为:沉积物>地表水>地下水.研究结果将为重金属污染环境的生态修复及可持续发展提供重要科学依据.

Heavy metal pollution seriously threatens the diversity and composition of microbial communities in various ecosystems.However,little is known about the effects of heavy metal pollution on the structure of microbial communities in the three habitats of"surface water-sediment-groundwater."Here,with help of 16S rRNA high-throughput sequencing technology,the diversity and composition of microbial communities,as well as the underlying controlling factors,were investigated and compared among the surface water,sediment,and groundwater of the Tanghe sewage reservoir.The results showed significant differences in the diversity of microbial communities among different habitats,with the highestαdiversity observed in groundwater rather than surface water or sediment.Meanwhile,microbial communities also displayed distinct compositions among the three different habitats.Specifically,Pedobacter,Hydrogenophaga,Flavobacterium,and Algoriphagus were dominant in surface water;metal-tolerant bacteria such as Ornatilinea,Longilinea,Thermomarinilinea,and Bellilinea prevailedin sediment;and Arthrobacter,Gallionella,and Thiothrix were abundant in groundwater.Furthermore,physicochemical factors and metal variables jointly determined the microbial community structure in the three habitats.Among the influencing factors,pH,NO_(3)^(-)-N,and Li were the main factors affecting the microbial structure in surface water;TP,NH_(4)^(+)-N,Cr,Fe,Cu,and Zn significantly impacted microorganisms in sediment;and only pH(not metal pollutants)was weakly associated with the microbial composition in groundwater.Overall,heavy metal pollution significantly shaped the microbial community structure in sediment,followed by that in surface water and groundwater.These results provide important scientific guidance for the ecological restoration and the sustainable development of heavy metal-polluted ecosystems.