Differential Impacts of Perfluorooctanoic Acid (PFOA) on Soil Microbial Communities in Aerobic and Anaerobic Agricultural Soils

Abstract

Perfluorooctanoic acid (PFOA) is a persistent environmental contaminant with the potential to disrupt soil-plant systems. This study investigated the impacts of PFOA on soil microbial viability and community composition under aerobic and anaerobic conditions, to understand microbial resilience and adaptability to pollutant stress. Soil samples from an uncontaminated agricultural field (2.26 ng/g) were amended with varying PFOA concentrations (0, 40, 60, 80, and 100 mg/kg) and incubated under controlled conditions for 7 days. Microbial viability was assessed through colony-forming unit (cfu) counts, while community composition was characterized via 16S rRNA gene sequencing. Results showed a significant decline (8–79%) in microbial viability at higher PFOA concentrations across both environments, with anaerobic soils exhibiting greater sensitivity, underscoring the role of oxygen availability in microbial pollutant tolerance. Taxonomic analysis revealed concentration-dependent shifts, with Actinobacteria and Proteobacteria dominating under aerobic conditions, and Chloroflexi, Bacteroidetes, and Acidobacteria prevailing under anaerobic conditions. The novelty of this study lies in its systematic comparison of microbial community responses and adaptive mechanisms under both aerobic and anaerobic soil conditions, providing critical insights into the differential impacts of PFOA that have previously not been explored.The findings highlight the ecological significance of resilient taxa in sustaining carbon and nutrient turnover in contaminated soils.