Enhanced bioremediation of organically combined contaminated soil by white rot fungal agent: physiological characteristics and contaminants degradation

Microbial remediation of organically combined contaminated sites is currently facing technical challenges. White rot fungi possess broad-spectrum degradation capabilities, but most of the studies are conducted on polluted water bodies, and few research focus on the degradation of combined organically contaminated soils. This study aimed to investigate the physiological changes in Trametes versicolor to enhance its simultaneous degradation ability towards benzo(a)pyrene (BaP) and TPH. The results demonstrated that Trametes versicolor, when subjected to liquid fermentation, achieved an 88.08% degradation of individual BaP within 7 days. However, under the combined contamination conditions of BaP and TPH, the BaP degradation rate decreased to 69.25%, while the TPH degradation rate was only 16.95%. Furthermore, the degradation rate of BaP exhibited a significant correlation with the extracellular protein concentration and laccase activities. Conversely, the TPH degradation rate exhibited a significant and positive correlation with the intracellular protein concentration. Solid-state fermentation utilizing fungal agents proved to be the most effective method for removing BaP and TPH, yielding degradation rates of 56.16% and 15.73% respectively within 60 days. Overall, Trametes versicolor demonstrated a commendable capability for degrading combined PAHs-TPH pollutants, thereby providing theoretical insights and technical support for the remediation of organically combined contaminated sites.