Seasonal Variation Of Microbial Community In Different Mine Wastewater Lake

Acid mine drainage(AMD),characterized by strong acidity and high metal concentrations,generates from the oxidative dissolution of metal sulfides.A large number of studies have shown that acidophiles play a pivotal role in the generation of AMD.However,the current research has paid little attention to the seasonal variations of microbial community structure in different mine wastewater with high metal concentration.In this paper,we collected the mine wastewater from an iron mine in Anhui Province in October 2015 and May 2016,July 2016,November 2016 and December 2016,respectively.The environmental parameters of all the samples were systematically determined.Based on the high-throughput sequencing technology,the microbial community structure in different mine wastewater was studied,and the seasonal variations of microbial community structure were analyzed.The relationship between environmental factors and microbial community structure was discussed,so as to provide a reliable theoretical basis for bioremediation of acidic wastewater environment.The main results were shown as followed:1)In DS neutral waste reservoir(pH 7.55),the concentration of SO42-was 4162.99 mg/L,the concentration of metal Ca(650.10 mg/L)and Mg(594.90 mg/L)were the highest.Taxonomic classification revealed that all high quality sequences were assigned to Bacteria,and the dominant phyla were Betaproteobacteria,Actinobacteria and Alphaproteobacteria,the dominant generawere Curvibacter and Rhodobacter.2)Over a full seasonal cycle in 2016,the pH of PT reservoir fluctuated between 3.01 and 3.16,and the concentration of SO42-was between 5929.99 to 11422.50 mg/L,the most abundant metal ions were Mg(668.10-1043.40 mg/L)and Al(294.03-636.30 mg/L),while the concentration of Fein this reservoir was at a low range(4.73-29.91 mg/L).Most of the environmental parameters reached the highest value in spring and reached the lowest value in summer throughout the year.The dominant phyla were Betaproteobacteria and Alphaproteobacteria,Ferrovum and Acidiphilium were predominant in all sampling seasons.The amount of Ferrovum showed a gradualdecreasing trend in spring,summer and autumn,and then reached the highest value in winter.The distribution ofAcidiphilium was abundant in spring and autumn,but less in summer and winter.3)The pH of TF reservoir was between 2.43 and 2.75,which was lower than that of the PT reservoir.Theconcentration of SO42-(4015.10-7199.18 mg/L)was about half of that of the PT reservoir,and the concentration in autumn and winter was higher than that in spring and summer.The most abundant metal ionsof TF were Mg(192.63-257.25 mg/L)and Al(125.28-214.80 mg/L),which was similar to PT reservoir,but the concentration was much higher than that of the TFreservoir,and Fe concentrationat TF reservoir was at a high range(99.30-171.60 mg/L).The dominant phyla and genera of TF were similar to that of PT reservoir,however,the distribution showed a huge difference.The highest distribution of Ferrovumoccurred in spring,followed by summer and autumn.Acidiphilium was predominant in summer,followed by spring,and reached the lowest in autumn.4)In the two acid reservoirs of PT and TF,the diversity of prokaryotic microorganisms increased with the increase of pH and the decrease of Fe concentration.The environmental factors of pHand Fe had a significant effect on the distribution of major genera.Leptospirillum and Acidithiobacilluswere positively correlated with Fe and TP,but negatively correlated with other environmental factors.On the contrary,Acidisphaera,Metallibacterium and other genera were negatively correlated with Fe and TP,but positively correlated with other environmental factors.