Remediation potential of an immobilized microbial consortium with corn straw as a carrier in polycyclic aromatic hydrocarbons contaminated soil

Polycyclic aromatic hydrocarbons (PAHs) are widespread in soils and threaten human health seriously. The immobilized microorganisms (IM) technique is an effective and environmentally sound approach for remediating PAH-contaminated soil. However, the knowledge of the remedial efficiency and the way IM operates using natural organic materials as carriers in complex soil environments is limited. In this study, we loaded a functional microbial consortium on corn straw to analyze the effect of IM on PAH concentration and explore the potential remediation mechanisms of IM in PAH-contaminated soil. The findings revealed that the removal rate of total PAHs in the soil was 88.25% with the application of IM after 20 days, which was 39.25% higher than the control treatment, suggesting that IM could more easily degrade PAHs in soil. The findings from high-throughput sequencing and quantitative PCR revealed that the addition of IM altered the bacterial community structure and key components of the bacterial network, enhanced cooperative relationships among bacteria, and increased the abundance of bacteria and functional gene copies such as nidA and nahAc in the soil, ultimately facilitating the degradation of PAHs in the soil. This study enhances our understanding of the potential applications of IM for the treatment of PAH-contaminated soil.