Characterization and soil remediation performance of a natural polycyclic aromatic hydrocarbon-degrading bacterial consortium (PD1).

Polycyclic aromatic hydrocarbons (PAHs) are persistent and toxic soil contaminants that pose significant risks to environmental and human health. In this study, a natural PAHs-degrading microbial consortium (PD1) was enriched from coal gangue backfill soil using phenanthrene as the sole carbon source. PD1 features Acidovorax and Pigmentiphaga as the dominant functional genera. The consortium achieved 70% phenanthrene removal within 3 days in liquid culture and demonstrated robust soil remediation performance, with 74.7% and 89.5% removal within 3 and 9 days, respectively, significantly outperforming native conditions. PD1 also degraded fluoranthene, pyrene, and benzo[a]anthracene, and exhibited strong tolerance to As(III) at concentrations up to 50 mg/L, while maintaining stable activity during long-term storage at 4°C. Metagenomic and metatranscriptomic analyses, together with the tentative annotation of two early-stage intermediates, supported a proposed major route for PHE degradation in PD1. The cooperative interactions among various functional microorganisms within the consortium drive the efficient degradation of PHE. These results establish PD1 as a robust, synergistic consortium with strong potential for the bioremediation of PAHs-contaminated soils.