Effects of acid mine drainage on microbial community development and physicochemical properties of mine contaminated sites in Southwest China

Abstract

Investigations of the microbial community structures, potential functions and physicochemical property are useful for risk assessments, microbial monitoring, and the biogeochemical behaviour of contained environment by Acid Mine Drainage (AMD). In this study, nine sediment sampling sites were selected at Panjiaozhuang Town, in Guizhou, China to analyze the pollution conditions and their influences on microorganisms. The physicochemical property results showed significant differences in sediment and water physico chemical properties at different group. Compared to the DS group, further studies revealed that US group (severely affected areas) showed strong acidity and high concentrations of heavy metals and salts. The community structure analysis indicated that AMD might enhance the functional bacteria, such as Thiomonas and Ferrovum (increases of 1.2 and 8.1 percent, respectively), and significantly increased the concentrations of Fe and sulfate through the oxidation of pyrite. The KEGG enrichment analysis demonstrated showed that the AMD promoted the migration of sulfur and Fe into water by enhancing bacterial metabolic pathways, such as dark oxidation of sulfur compounds and dark iron oxidation. This article is of great significance for understanding the transformation of pollutants by AMD and provides reference for subsequent bioremediation.

Keywords: Acid mine drainage; Community structure; Metabolic pathways; Thiomonas.

Fig. 1

The location figure of the Study Area. This map is based on the standard map No.GS(2020)4632 downloaded from the standard map service website of National Administration of Surveying, Mapping and Geoinformation of China (http://bzdt.ch.mnr.gov.cn/) with no modification to the base map.

Fig. 2

Comparative analysis of microbial alpha diversity index in US, MS, and DS sediments.

Fig. 3

PCA (a) and RDA (b) principal component analysis of each classification unit.

Fig. 4

Relative abundance of microbial community in each group (at phyla level).

Fig. 5

(a) Relative abundance of microbial community in each group (at genes level). (b, c) Comparisons the rate of dominant species between DS&US Group and MS&US group (at genes level).

Fig. 6

(a) Relative abundance of metabolic pathway in each group. (b, c) Comparisons the rate of metabolic pathway between DS&US group and MS&US group.

Fig. 7

Correlation analysis between dominant species and environmental factors.

Fig. 8

Conceptual mechanism of how AMD affects environments.