Study On Eukaryotic Diversity Of Arsenic Mining Area By High-throughput Sequencing

Arsenic(As)is a toxic carcinogenic element.The widespread use of arsenic and Arsenide has led to an increasingly serious threat of arsenic contamination.Previous remediation of arsenic-contaminated soil includes physical,chemical,and phytoremediation methods.Phytoremediation has gradually become a popular method for mining areas soil remediation because of its no additional pollution and economic benefit.Most of the previous research focused on the plant,ignoring the important contribution microorganisms made to the arsenic absorption and transport.In this study,the eukaryotes in soil and plant mixtures from different functional areas in Shimen realgar mining area was investigated by the 18 S high-throughput sequencing method.The dominant microorganisms in different functional areas of the arsenic mineral area were identified,and higher arbuscular mycorrhizas fungi were screened out.The correlation between the dominant arbuscular mycorrhizal fungi and various environmental factors in the Shimen realgar mining area was detected.The purpose of this study is to investigate the representative microorganisms in the mining area,to provide a theoretical basis for the remediation arsenic-contaminated soil by a combination of arbuscular mycorrhizal fungi and plantsand to enrich the effect on arsenic geochemical behavior o by microorganisms.The results of the study are:(1)The average total sulfur content in the smelting area,concentrator and tailings reservoir is 3.33%,3.43% and 2.67 %.Sulfur in excess of the standard existed in realgar mining area.(2)Arsenic in excess of the standard of existedin the realgar mining area,the arsenic residual level is 47.2 ~ 477 times and 59.0 ~ 597 times higher than the mean background value of Hunan and the national background.The highest average arsenic content in soil sample was 2.93 mg/kg in the smelting area,followed by 2.27 mg/kg in the concentrator,and the lowest in the tailings was 0.840 mg/kg.The difference in arsenic content among the samples in the smelting area is the highest.(3)Antimony in excess of the standard existed in all the mining areas.The concentrations of smelting,concentrator and tailings ponds were 58.8 mg/kg,49.8 mg/kg and 46.8 mg/kg,respectively.The average antimony value is 14.6 to 23.7 times and 41.1 to 66.7 times higher than the mean background value of Hunan and the national background value,respectively.No significant difference was detected among the three areas.(4)The totally different number of OTUs in the smelter,beneficiation plant and tailings pond is 12032,7325,and 7614,respectively.(5)The result of 18 S Illumina high-throughput sequencing showed that the fungi were the main eukaryotes in the region.Rhizophagus,Acaulospora,and Gigaspora were the dominant genusof arbuscular mycorrhizal fungi Knufia,Rhodotorula,and Exophiala were also found in the functional areas of the mine.(6)The result of Redundancy analysis showed that significant positive correlation existed between arbuscular mycorrhizal fungi concentrationand pH level,as well as significant negative correlation existed between total organic carbon,available potassium,nitrogen and arbuscular mycorrhizal fungi content.