酸性矿山排水影响下水库及其入库流域水体细菌多样性与环境因子的关系

Relationship between bacterial diversity and environmental factors in reservoirs and their inflow basins under the influence of acid mine drainage

为了解酸性矿山废水排水处沿流域至水库底层水体细菌群落结构的沿程变化,探索其环境影响因素.采用高通量测序技术并结合主成分分析(principal component analysis,PCA)方法,对2019年9月采集受酸性矿山废水(acid mine drainage,AMD)影响的12个水样进行研究.结果表明,入库流域水样中细菌群落多样性变化趋势不明显,从表层至底层细菌多样性不断升高.在门水平上受AMD影响的细菌主要由变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes,0.21%—12.96%)、厚壁菌门(Firmicutes,0.15%—14.48%)和放线菌门(Actinobacteria,0.06%—4.64%)构成.其中,变形菌门中的α-变形菌纲(Alphaproteobacteria,2.42%—61.99%)、β-变形菌纲(B etaproteobacteria,1.29%—63.53%)和γ-变形菌纲(Gammaproteobacteria,6.41%—63.09%)为优势菌类.从不同空间位置浮游细菌群落组成来看,不动杆菌属(Acinetobacter)在受AMD影响流域上游至水库底层水样中均占较大比例,为2.13%—-57.84%,假单胞菌属(Pseudomonas,3.86%—12.29%)、铁细菌属(Ferrovum,0.97%—13.21%)和拟杆菌属(Bacteroides,0.01%—5.02%)是上游水样中的优势菌属,噬氢菌属(Hydrogenophaga,0—5.94%)、盖氏铁柄杆菌属(Gallionella,1.45%-11.91%)和新鞘氨醇杆菌(Novosphingobium,0—5.34%)是中游占比较大的菌属,红细菌属(Rhodobacter,12.73%—57.52%)是下游水样和水库水样中的优势细菌.造成AMD影响下不同位点处水体浮游细菌群落组成差异的环境因子各不相同,入库流域水体细菌群落主要受NH_(4)^(+)-N、总磷(TP)和SO_(4)^(2-)影响,Mg^(2+)和As^(3+)也与入库流域水体中细菌多样性存在一定相关关系,水库水体中细菌群落主要受水温(T)影响.研究结果将有助于为酸性矿山废水微生物资源及生态环境的研究提供理论依据.

To understand the changes in bacterial community structure along the watershed to the bottom of the reservoir at the acid mine drainage and to explore the environmental impact factors.Twelve water samples affected by acid mine drainage(AMD)were collected in September 2019 using high-throughput sequencing technology and principal component analysis(PCA).The results showed that the trend of bacterial community diversity in the water samples from the inlet basin was not obvious,and the bacterial diversity increased from the surface to the bottom layer.The bacteria affected by AMD at the phylum level were mainly Proteobacteria,Bacteroidetes(0.21%—12.96%),Firmicutes(0.15%—14.48%),and Actinobacteria(0.06%—4.64%).Of these,the phylum Alphaproteobacteria(2.42%—61.99%),the phylum Betaproteobacteria(1.29%—63.53%)and the phylum Gammaproteobacteria(6.41%—63.09%)were the dominant bacterial groups.In terms of the composition of the planktonic bacterial community at different spatial locations,Acinetobacter(2.13%—57.84%),Pseudomonas(3.86%—12.29%),Ferrobacter(0.97%—13.21%),and Bacteroides(0.01%—5.02%)were the most abundant species in the water samples from the upstream to the bottom of the reservoirs affected by AMD.Pseudomonas(3.86%—12.29%),Ferrovum(0.97%—13.21%)and Bacteroides(0.01%—5.02%)were the dominant genera in the upstream water samples,Hydrogenophaga(0—5.94%),Gallionella(1.45%—11.91%)and Novosphingobium(0—5.34%)were the dominant genera in the midstream,and Rhodobacter(12.73%—57.52%)were the dominant bacteria in the downstream water samples and in the reservoir water samples.The environmental factors leading to the difference in the composition of the planktonic bacterial community at different sites under the influence of AMD are different,NH_(4)^(+)-N,total phosphorus(TP)and SO_(4)^(2-)were the main factors affecting the bacterial community in the inflow basin.Mg^(2+)and As^(3+)also had a certain correlation with the bacterial diversity in the inflow basin,and bacterial community in reservoir water is mainly affected by water temperature(7).The results of the study will help to provide a theoretical basis for the study of the microbial resources and ecological environment of acid mine wastewater.