Spatial and temporal analysis of the microbial community in the tailings of a Pb-Zn mine generating acidic drainage

Abstract

Analysis of spatial and temporal variations in the microbial community in the abandoned tailings impoundment of a Pb-Zn mine revealed distinct microbial populations associated with the different oxidation stages of the tailings. Although Acidithiobacillus ferrooxidans and Leptospirillum spp. were consistently present in the acidic tailings, acidophilic archaea, mostly Ferroplasma acidiphilum, were predominant in the oxidized zones and the oxidation front, indicating their importance to generation of acid mine drainage.

Fig. 1.

Location, overview, and vertical profile of the tailings impoundment at the Fankou Pb-Zn mine, Renhua, Guangdong Province, People's Republic of China. For abbreviations of tailings samples, see the text.

Fig. 2.

Distribution of phylotypes in the 16S rRNA gene libraries derived from the Fankou (and Lianping) Pb-Zn mine tailings and associated AMD.

Fig. 3.

Microbial community profiles (n = 4) based on T-RFLP analysis of 16S rRNA genes digested with the restriction enzyme MspI. Taxonomic affiliation of TRFs was identified by in silico T-RFLP analysis of all retrieved 16S rRNA gene sequences and experimental determination of TRFs of representative clones of the abundant OTUs (>5%) from each clone library. TRF-41 is most frequently associated with the Firmicutes, Actinobacteria, and Bacteroidetes; TRF-71 is exclusively related to the Ferroplasma genus and “alphabet plasmas” within the Archaea; TRF-98 is most frequently associated with A. ferrooxidans but is also shared by many other proteobacterial phylotypes detected in the unaltered and moderately acidic tailings; TRF-205 represents Leptospirillum spp. and several deltaproteobacterial phylotypes detected in the unaltered or moderately acidic tailings.

Fig. 4.

PCA analysis of the Fankou (and Lianping) mine tailings and associated AMD microbial communities based on T-RFLP patterns derived from the 16S rRNA genes. Error bars represent SD (n = 4).