Interplay between denitrifying and sulfate-reducing bacterial communities under acid mine drainage stress

Abstract

Acid mine drainage (AMD) pollution leads to the enrichment of sulfate in paddy soil. The interplay between denitrifying and sulfate-reducing bacteria across varying soil depths, and their response to AMD pollution is not yet fully understood. The responses of denitrifying and sulfate-reducing bacteria(SRB) to AMD pollution were analyzed by collecting soil samples at four depths (0–10 cm, 10–20 cm, 20–40 cm, 40–60 cm) under two treatments (AMD-polluted and control soil). AMD pollution resulted in a significant decrease in pH value, elevated SO42- and metal concentrations. Compared to the control soil, denitrifying and sulfate-reducing bacteria in AMD-polluted soils were more sensitive to environmental fluctuations. Co-occurrence analysis revealed that there were more microbiological linkages and nodes in control soil than in polluted soil. Denitrifying and sulfate-reducing bacteria can maintain part of N and S cycle under long-term AMD pollution by increasing the negative correlation in ecological network. Desulfobacca exhibited a positive correlation with nitrate and held a significant position in the symbiotic network, suggesting its potential important role in inhibiting nitrogen loss. This study revealed the intricate ecological network of functional communities, which could have important implications for environmental management and the development of sustainable agricultural practices in areas affected by AMD pollution.