Arsenic pollution from human activities drives changes in soil microbial community characteristics

Area of Science:

• Environmental Science
• Soil Microbiology
• Agricultural Science

Background:

• Soil arsenic (As) contamination poses a significant threat to plant productivity, soil quality, and sustainable agriculture.
• While the impact of As on rice yield is well-documented, its effects on soil microbial communities and their networks remain underexplored.

Purpose of the Study:

• To investigate the impact of varying arsenic contamination levels on bacterial abundance, diversity, and co-occurrence networks in paddy soils.
• To identify specific bacterial phyla affected by As pollution and understand their roles in microbial network stability.

Main Methods:

• Utilized high-throughput sequencing to analyze bacterial communities in paddy soils with different As contamination levels.
• Constructed microbial co-occurrence networks to assess community structure and interactions under As stress.
• Correlated bioavailable and total As concentrations with the relative abundance of key bacterial phyla.

Main Results:

• Arsenic pollution significantly reduced soil bacterial diversity (p < 0.001).
• Bioavailable As negatively correlated with Actinobacteria and Acidobacteria; As positively correlated with Chloroflexi, Betaproteobacteria, and Bacteroidetes.
• Firmicutes abundance decreased with increasing total As concentration, and microbial network structures shifted significantly with As pollution.

Conclusions:

• Arsenic contamination profoundly alters soil microbial community structure and function in paddy ecosystems.
• Acidobacteria are crucial for maintaining microbial network integrity in As-contaminated soils.
• These findings highlight the threat of As pollution to soil health and sustainable agricultural development.