The Study on the effect of mercury pollution on soil microorganisms around mercury mining area

Abstract

Abstract In order to further explore the effects of soil mercury pollution at different distances from the mercury mining area on soil microbial diversity and community structure, 2m, 20m, 30m, 500m and 650m from the periphery of the mercury mining area were selected as soil sampling areas. Four different points were randomly selected from the soil sampling areas of 2m, 20m, 30m, 500m and 650m to collect 0-20cm soil samples under the surface, a total of 20 soil samples. Soil microbial DNA was extracted from 20 soil samples after treatment, and then soil microbial DNA was sequenced by high-throughput sequencing technology. The results showed that in the three levels of order, family and genus, the number of bacteria and fungi in the high mercury soil of 2–30 m from the mercury mining area was significantly higher than that in the high mercury soil of 500–650 m from the mercury mining area. At the level of family and genus, the number of unique bacteria and fungi to soil samples at different points at the same distance was quite different. The results of the effect on the microbial community structure showed that at the order level, the dominant bacteria in the high mercury soil or medium and high mercury soil at 2m, 20m, 30m, 500m, 650m from the mercury mining area were Sphingomonadales and Sphingobacteriales, and the dominant fungi were Agaricales and Sebacinales. At the family level, the dominant bacteria were Sphingomonadaceae and Chitinophagaceae, and the dominant fungi were Sebacinaceae and Hygrophoraceae. At the genus level, the dominant bacteria were norank_Acidobacteria_Gp6, Sphingomonas, norank_Acidobacteria_Gp4, and the dominant fungi were Hygrocybe and Sebacina. The internal heterogeneity of soil caused significant differences in unique bacteria and fungi at the same site, and the emergence of dominant bacteria and fungi was a manifestation of high adaptability to long-term mercury stress and other stresses in soil, which provided a scientific reference for further exploring the mechanism of synergistic mercury enrichment between microorganisms and plants.