Environmental Heterogeneity Of The AMD Microbial Community Structure And Genotype Distribution Pattern Of Acidothiobacillus

Object:The metabolic activities of microorganisms are central to the biogeo-chemical cycles of elements in any ecosystem.However,there are few reports on the geographical differentiation and micro-diversity of microbial population in terrestrial environment at home and abroad.Because of the isolation and harsh living conditions of extreme eosinophilic habitat in the AMD environment,Thus,these acid mine drainage provide excellent opportunities to study microbial succession.The study of the environmental factors on the microbial community of AMD and the genotype distribution pattern of the Acidothiobacillus population,not only for the biological repair of AMD environmental pollution to provide a theoretical basis,but also provide basic information which to got high-value metal from the waste ore or low-grade ore.will provide a theoretical basis for the bioremediation of AMD environmental pollution and provide a high efficiency for the recovery of high value metals from waste or low grade ore Basic information.Methods:Based on the high-throughput sequencing technology and determination of environmental physical and chemical parameters,the microbial community structure of acid mine wastewater and sediments was analyzed,and the rep-PCR molecular fingerprinting and housekeeping multi locus sequence typing were used to analyze the The genetic heterogeneity of Acidithiobacillus spp.In order to elucidate the niche and geologic segregation of heterogeneous environment and the effect of environmental factors on microbial community structure and to reveal the effect of environmental selection on population differentiation.By analysising the results of our study,main conclusions are gianed as follows: Results:1.Mining activities pose severe environmental risks worldwide,generating extreme pH conditions and high concentrations of heavy metals,which can have major impacts on the survival of organisms.In this work,pyrosequencing of the V4 region of the 16 S rDNA was used to analyze the bacterial communities in acid mine drainage and sediments samples from 3 mining areas of Yunfu sulfide mine,Dexing copper mine and Yongping copper mine across Southeast China.Pyrosequencing-derived data set and sequencing of 16 S rRNA genes showed the analyzed bacterial sequences were affiliated to the 31 phylogenetic groups in all samples.The acid mine drainage and sediments samples bacterial community was dominated by proteobacteria(31.7%)and Chloroflexi(5.0%),followed by Bacteroidetes(4.0%)?Firmicutes(2.4%)?Acidobacteria(2.3 %)?Actinobacteria(1.5%)?Nitrospira(1.4%)and Deltaproteobacteria(1.0%).All other bacterial phyla were represented by <1% of the classified reads.However,the environment type played an important role in bacterial community divergence,the composition and frequency of OTUs in the sediments were different from those of the acid mine drainage samples.RDA analysis identified physicochemical characteristics as important distinguishing factors between the bacterial communities from the different types of mine environment.The bacterial communities from the sediments and acid mine drainage samples were different in structure and composition,and the Fe2+?SO42-?Co?Zn and EC present in these environments contributed to the observed differences.2.One hundred and seventy-four strains were isolated from three different sites(Guangdong yunfu,Jiangxi dexing and Jinagxi yongping)in China.Of the whole isolates grouped five cluster by 16S–23S rRNA gene sequence analysis,It suggested that Acidithiobacillus spp.showed a great genetic diversity.This result was similar with that obtained by rep-PCR.In this present study,the A.ferrooxidans strains were always divided into two groups in phylogenetic and BOXAIR fingerprinting cluster analysis,however,these were clustered one group in the ERIC dendrogram.the ITS gene is proved a very useful in distinguishing closely related species or subspecies of Acidithiobacillus,and BOX-PCR is recommended as reliable tool for genetic heterogeneity analysis of Acidithiobacillus.3.In this study,the design and implementation of a Multilocus Sequence Typing scheme for Acidithiobacillus is described.Overall,42 strains profiling using concatenated sequences resulted in 8 different STs.32 strains A.ferrooxidans had 6 different STs,Five STs were represented by a single isolate(ST-2 to ST-6),while the ST1 was the most frequent STs.10 strains A.ferridurans had 2 different STs,ST7 and ST8,respectively.Binding rep-PCR found,the genotype of Acidothiobacillus spp.showed a certain distribution pattern.Among all the strains,the five isolates from Daye of Hubei belonged to a ST8.and Polymorphism calculations showed that different species of Acidothiobacillus were affected by different evolutionary slections.