Variations Of Microbial Community And Metagenomics Analysis In An Acid Minedrainage Lake In Anhui Province

Acid mine drainage(AMD)which has strong acidity and high content of heavy metals generated by the oxidation of metal sulfide minerals.Acidophiles can accelerate the process by oxidizing the ferrous iron.In order to understand the acidophiles community composition and its relationship with geochemical characteristics,the AMD samples were collected from AMD lake in Anhui Province.We studied the changes of procaryotic and eukaryotic community across different seasons by clone library and high-throughput sequencing technology,and the relationship between microbial connunity composition and physiochemical factors.Functional genes of different seasons were analyzed by metagenomics as well.The results of the study were as following:(1)The acidity of AMD was strong whose pH was 2.94±0.03 and 3.15±0.01 in autumn and winter.The contents of Mg 、 Al and SO42-were high,with the concentration of 1103.70±108.50mg/L,600.60±42.91 mg/L,10398.98±767.55mg/L in autumn and 1232.70±11.40mg/L 、 673.40±6.71mg/L 、 13015.91±1962.68mg/L in winter.The concentrations of ions increasedslightlyfrom autumn to winter.(2)The microbial community diversity was higher in autumn than winter.There were significnt changes for prokaryotic microbial composition between two seasons.The abundance of Alphaproteobacteria and Actinobacteria raised markedly from autum to winter.However the proprotion of Betaproteobacteria declined hugely.(3)The genus like Ferrovum(35.28%±16.88%),Acidobacterium(16.03%±4.99%),Acidiphilium(10.74%±2.64%)were predominant in autumn,but Acidiphilium(33.74%±1.87%),Acidisphaera(10.34%±1.86%),Granulicella(6.52%±1.85%)were major groups in winter.(4)Correlation analysis revealed that pH,temperature and aluminum hadstrong impact on microbial community structure.(5)The eukaryoticcommunity in AMD lake were mainly composed of Coccomyxa and Ochromonas in both autum and winter.Coccomyxa was dominant in two seasons.(6)KEGG analysis of metagenomics revealed that the abundance of photosynthetic carbon fixationwas raising across three seasons,which was 1.63‰,2.06‰ and 2.50‰in winter,spring and summer,respectively.Photosystem I,photosystem II and the key enzyme erredoxin-NADP+ reductase showed the same trend across three seasons.(7)There were not significant changes for nitrogen fixation genes,sulfur oxide genes and ferrous iron oxide genes.