[Microbial Community Composition and Diversity in Metal Sulfide Mine Water Systems].

To understand the characteristics of heavy metal pollution and physicochemical properties caused by mining activities in mine water systems and the response of the microbial community to habitats with different contamination levels, this study selected different types of water (mining area wastewater, spoil heap area wastewater, dressing area wastewater, mine seepage water, and pond water) as the variables related to the mining activities in the water system of the Shizishan mining area in Tongling, Anhui Province. The pollution characteristics and physicochemical properties were compared, and the relationship between environmental factors and the microbial communities were analyzed. The results showed that the content of heavy metals, the physicochemical properties, and the structure and diversity of the microbial community of different types of water were significantly different in different mine areas, among which the most seriously polluted areas were the mining area, the spoil heap area, and the dressing area. There were significant differences in microbial community structure among different functional types of wastewaters, and the diversity and abundance of the microbial community in DW with the heaviest heavy metal pollution were weaker than those in the other four regions. PcoA analysis showed that samples of similar water types had similar clustering. Spearman correlation heat map analysis and canonical correlation analysis (CCA) indicated that heavy metal pollution, pH, electrical conductivity (EC), SO2-4, and chemical oxygen demand (COD) had the greatest effect on the microbial communities in the mine water systems. Moreover, this study found that Proteobacteria, Euryarchaeota, and Bacteroidetes dominated in mine water systems, and their potential use could be explored in the future. Our results provide a better understanding of the different types of water pollution characteristics in mine water systems and the key factors that determine the microbial community structure.

[Effects of Different Land Use Types on Microbial Community Diversity in the Shizishan Mining Area].

Soil microorganisms play an important role in ecosystem function. Soil microbial community structure can be used to feed back the status of heavy metal pollution in soil at different functional areas of mines related to mining activities. Samples of four different land use types (vegetable garden, tailings reservoir, heap mining area, and dressing area) were collected in the Shizishan mining area, Tongling, Anhui Province, to determine the effect of heavy metal pollution on microbial community structure. Soil physical and chemical properties and heavy metal contents of the four different land use types were measured, and soil microbial community abundance and structure diversity were analyzed by Illumina MiSeq high-throughput sequencing technology. The results show that there are significant differences in physical and chemical properties between different regions. The comprehensive pollution index of Nemerow is heap mining area (7.28) > dressing area (6.99) > tailings reservoir (6.55) > vegetable garden (5.92). The distribution of microbial community abundance and structure diversity was tailings reservoir > dressing area > vegetable garden > heap mining area. In addition, principal coordinates analysis (PCoA), canonical correspondence analysis (CCA), and correlation analysis showed that land use type, soil pH and heavy metal content had significant effects on the microbial community. The dominant soil microbial communities at the phylum level were Proteobacteria, Bacteroidetes, Acidobacteria, and Actinobacteria, at the class level were ß-Proteobacteria, α-Proteobacteria, and γ-Proteobacteria, and at the genus level were Flavobacterium, Kaistobacter, and Ramlibacter. The bacteria that are more tolerant to heavy metals are Proteobacteria, Firmicutes, ß-Proteobacteria, and Kaistobacter. These results have deepened our understanding of microbial changes and aggregation patterns in soils of heavy-metal-contaminated mining areas. This study can provide bacterial species and theoretical basis for bioremediation of heavy metal mining areas.

[Vertical distribution of physicochemical characteristics and the microbial diversity in different spatial sediments samples in Lake Taihu].

The physicochemical characteristics, nutritions and the microbial community diversity of sediment core samples of three different space locations in the Lake Taihu were studied by fumigation-digestion and PCR-DGGE analysis respectively. The results indicated that below the surface of sediments Eh declined rapidly with increase of sediment depth and it was under anaerobic condition except the top layer of sediment. pH value changed silightly in the profile of sediments, which ranged from 7.2 to 7.8. TN and TP concentrations in sediments of Lake Taihu were high,and the maximum concentrations reached 2.436 mg/g and 0.731 mg/g, respectively. Their vertical profiles showed that TN and TP concentrations in surface sediments were much higher than in deeper layers and decreased with the increase of the depth of sediment layers. OM concentrations declined rapidly at the top 15 cm of sediment layers. There were prominent difference spatially in microbial diversity and the comparability and dynamics of community structure between different sediment samples of different space locations and different depth. The little significant correlation at alpha < or = 0.05 level was observed between the Eh, pH, percentage organic matter, TN concentration and TP concentration and microbial community structure diversity index except of TN concentration and percentage organic matter.