Variations Of Microbial Community In Acid Mine Drainage And Metagenomics Analysis Of Samples In Different Seasons

Acid mine drainage?AMD?which has strong acidity and high content of heavy metals and sulfate generated by the oxidation of waste ore exposed to the atmosphere,and acidophilus plays vital role in this process.Based on high-throughput sequencing,this paper analyzed the changes of microbial communities in acid mine drainage with different properties and their relationship with environmental factors,It then used metagenomics to analyze the changes in microbial community function in AMD in different seasons,based on binning of Metagenomics,construct high-quality bins,and analyze their metabolic pathways and functional genes.The specific research results were as follows:?1?Four representative groups of acid mine wastewater from an iron ore mine in Anhui were collected.Among them,the pH of the dumping site acid reservoir?PT?was the highest,3.15±0.01,the concentration of Fe²⁺was 17.78±3.55 mg/L;The pH of Dahuang mountain acid reservoir?DH?was slightly lower at 2.70±0.01,the concentration of Fe²⁺was as high as 88.85±13.39 mg/L;The pH of the sample,which small-scale acid water XA1-XA3,was very close to the DH acid reservoir,was 2.69±0.02,However,the concentration of the Fe²⁺was lower 9.66±1.26 mg/L;it was also the most acidic in a small range of acid water XA4,the pH was only 2.51,and the concentration of Fe²⁺was 23.54 mg/L.?2?The weakest acidic PT acid reservoir was mainly the chemical energy heterotrophic bacteria Acidiphilium?33.36±1.49%?;The strong acidity,the highest Fe²⁺concentration of the DH acid reservoir in the chemical energy autotrophic bacteria Ferrovum?66.51±1.00%?and the Leptospirillum?22.45±1.89%?had an absolute advantage;In the samples XA1-XA3 with low Fe²⁺concentration,there were both chemical energy heterotrophic bacteria Acidiphilium?11.50±4.93%?and chemical energy autotrophic bacteria Acidithiobacillus?4.48±1.87%?;In the XA4 samples with the strongest acidity,the chemically resistant autotrophic bacteria Acidithiobacillus?39.86%?and Leptospirillum?15.76%?were dominant.?3?The Bioenv command analysis by R language showed that pH,Fe²⁺,Na,Mg,and TOC were the environmental factor combinations that affect the microbial community structure in acid wastewater samples.The CCA results showed that pH and Fe²⁺had the most significant impact on the community structure,with contribution rates of 32.49%and 29.31%respectively.?4?Analyzation of the functional genes related to heavy metal and acid resistance in five different seasons samples of January,May,July,November and December.The results showed that the gene which encoding ATP cation transport enzyme was the highest in sample January and the lowest in July,consistent with the concentration distribution of the relative cation in the sample.Among the acid resistance-related functional genes,the abundance of the chaperone protein resistance system composed of DnaK,DnaJ and GrpE in five samples was consistent with the change in acidity?5?The KEGG annotation results showed that the CBB cycle was the essential carbon fixation pathway in the samples.The critical enzymes for carbon fixation were relatively abundant in samples July and May.Ferrovum was the most crucial carbon fixation microorganism.In nitrogen metabolism,the nitrogen-fixing gene nifHDK was detected in each sample,and the microorganisms related to nitrogen fixation were mainly Methylococcus.The acidophilic bacteria associated with sulfur oxidation and iron oxidation are Acidiphilium and Ferrovum,respectively.?6?A total of 18 high-quality bins were obtained by Binning technology.Among them,the bin07 with the highest abundance and was highly similar to Acidisphaera.Due to the lack of Sox multienzyme complex and cytochrome c,bin07 cannot use thiosulfate and Fe²⁺as electron donors.In response to adversity,bin07 contains kefB-encoded Na⁺/H⁺antiporter against low pH,mgtA-encoded Mg²⁺transport protein,czcD-encoded Ni²⁺/Co²⁺/Zn²⁺ion pump against heavy metal stress,and katG-encoded catalase against oxidative stress.