Contrasting response strategies of microbial functional traits to polycyclic aromatic hydrocarbons contamination under aerobic and anaerobic conditions

PAHs (Polycyclic aromatic hydrocarbons) are widely distributed in soil ecosystems, but our knowledge regarding the impacts of PAHs effects on soil microbial functional traits is limited. In this study, we evaluated the response and regulating strategies of microbial functional traits that are associated with the typical C, N, P, S cycling processes in a pristine soil under aerobic and anaerobic conditions after the addition of PAHs. Results revealed that indigenous microorganisms had strong degradation potential and adaptability to PAHs especially under aerobic conditions, while anaerobic conditions favored the degradation of high molecular weight PAHs. PAHs exhibited contrasting effects on soil microbial functional traits under different aeration conditions. It would probably change microbial carbon source utilization preference, stimulate inorganic P solubilization and strengthen the functional interactions between soil microorganisms under aerobic conditions, while might cause the increase of H2S and CH4 emissions under anaerobic conditions. This research provides an effective theoretical support for the ecological risk assessment of soil PAHs pollution.