The Application of an Effective Microbial Fermentation Product as a Biostimulant in the Bioremediation of Soil Contaminated with Benzo[a]pyrene

The efficiency of polycyclic aromatic hydrocarbon (PAH) removal by indigenous microorganisms is often suboptimal, resulting in constraints on its practical application. To enhance the degradation efficiency of benzo[a]pyrene (B[a]P) in contaminated soil, an effective microbial fermented product (EMF) was employed as a biostimulant. Our findings demonstrated that when 1‱ or 1‰ (w/w) of the EMF was applied to the B[a]P-contaminated soil for 21 days, the biodegradation rates of the B[a]P were 59.37% and 100%, respectively, which is much higher than that by the natural attenuation (18.79%). The abundance of the 16S rDNA and PAH-RHDα GP genes were both significantly increased due to the applied EMF. Soil enzymatic activities were also affected, to different degrees, by the addition of the EMF. The diversity, composition, and functionality of the soil microbial community also changed to varying degrees. These results suggest that the use of the EMF to enhance the biodegradation of the B[a]P in soil may hold promise for the microbial remediation of PAH-contaminated soils.