Pyrosequencing-based assessment of bacterial community structure in mine soils affected by mining subsidence

Based on the 454 pyrosequencing approach, this research evaluated the influence of coal mining subsidence on soil bacterial diversity and community structure in Chinese mining area. In order to characterize the bacterial community comparatively, this study selected a field experiment site with coal-excavated subsidence soils and an adjacent site with non-disturbed agricultural soils, respectively. The dataset comprises 24512 sequences that are affiliated to the 7 phylogenetic groups: proteobacteria, actinobacteria, bacteroidetes, gemmatimonadetes, chloroflexi, nitrospirae and unclassified phylum. Proteobacteria is the largest bacterial phylum in all samples, with a marked shift of the proportions of alpha-, beta-, and gammaproteobacteria. The results show that undisturbed soils are relatively more diverse and rich than subsided soils, and differences in abundances of dominant taxonomic groups between the two soil groups are visible. Compared with the control, soil nutrient contents decline achieves significant level in subsided soils. Correlational analysis showed bacterial diversity indices have significantly positive correlation with soil organic matter, total N, total P, and available K, but in negative relation with soil salinity. Ground subsidence noticeably affects the diversity and composition of soil microbial community. Degeneration of soil fertility and soil salinization inhibits the sole-carbon-source metabolic ability of microbial community, leading to the simplification of advantage species and uneven distribution of microbial species. This work demonstrates the great potential of pyrosequencing technique in revealing microbial diversity and presents background information of microbial communities of mine subsidence land.