title: Shifts in microbial community composition and function in the acidification of a lead/zinc mine tailings.
abstract: In an attempt to link the microbial community composition and function in mine tailings to the generation of acid mine drainage, we simultaneously explored the geochemistry and microbiology of six tailings collected from a lead/zinc mine, i.e. primary tailings (T1), slightly acidic tailings (T2), extremely acidic tailings (T3, T4 and T5) and orange-coloured oxidized tailings (T6). Geochemical results showed that the six tailings (from T1 to T6) likely represented sequential stages of the acidification process of the mine tailings. 16S rRNA pyrosequencing revealed a contrasting microbial composition between the six tailings: Proteobacteria-related sequences dominated T1-T3 with relative abundance ranging from 56 to 93%, whereas Ferroplasma-related sequences dominated T4-T6 with relative abundance ranging from 28 to 58%. Furthermore, metagenomic analysis of the microbial communities of T2 and T6 indicated that the genes encoding key enzymes for microbial carbon fixation, nitrogen fixation and sulfur oxidation in T2 were largely from Thiobacillus and Acidithiobacillus, Methylococcus capsulatus, and Thiobacillus denitrificans respectively; while those in T6 were mostly identified in Acidithiobacillus and Leptospirillum, Acidithiobacillus and Leptospirillum, and Acidithiobacillus respectively. The microbial communities in T2 and T6 harboured more genes suggesting diverse metabolic capacities for sulfur oxidation/heavy metal detoxification and tolerating low pH respectively.
authors.affiliation: State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China.
authors.forename: Lin-Xing
authors.initials: LX
authors.lastname: Chen
authors.forename: Jin-Tian
authors.initials: JT
authors.lastname: Li
authors.forename: Ya-Ting
authors.initials: YT
authors.lastname: Chen
authors.forename: Li-Nan
authors.initials: LN
authors.lastname: Huang
authors.forename: Zheng-Shuang
authors.initials: ZS
authors.lastname: Hua
authors.forename: Min
authors.initials: M
authors.lastname: Hu
authors.forename: Wen-Sheng
authors.initials: WS
authors.lastname: Shu
mesh_terms: D000143:Acids / Q000737:chemistry*; D001419:Bacteria / Q000145:classification* / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D044822:Biodiversity; D004785:Environmental Pollutants / Q000633:toxicity; D005798:Genes, Bacterial / Q000235:genetics; D007854:Lead / Q000737:chemistry / Q000378:metabolism; D008906:Mining; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D015032:Zinc / Q000737:chemistry / Q000378:metabolism
chemical_list: D000143:Acids; D004785:Environmental Pollutants; D012336:RNA, Ribosomal, 16S; D007854:Lead; D015032:Zinc