Assessing the Bioremediation Potential of Native Amazonian White-Rot Fungi in a Soil Heavily Polluted by Hydrocarbons

Soil contamination by petroleum hydrocarbons in the Ecuadorian Amazon represents a persistent environmental challenge, with many sites exhibiting contamination aged 30–40 years. This study evaluated eight native white-rot fungal (WRF) strains isolated from Yasuní National Park for the degradation of total petroleum hydrocarbons (TPH) and pyrene in a heavily polluted, aged soil from the Sacha Oil Field (Orellana Province, Ecuador). Treatments included Porogramme epimiltina QCAM7782, Trametes menziesii QCAM7783 and QCAM7790, Bjerkandera sp. QCAM7784, Phlebiopsis sp. QCAM7787, Ganoderma cf. parvulum QCAM7791, Trametes villosa QCAM7793 and Lentinus crinitus QCAM7796, as well as a dual-strain consortium (G. cf. parvulum + T. menziesii). All fungal treatments achieved 42–64% TPH C8–C40 removal in 60 days, outperforming natural attenuation (15 ± 1%) and substrate-amended controls without fungi (14 ± 7%) (Tukey HSD, p < 0.05). T. menziesii QCAM7783 exhibited the highest mean TPH removal (64 ± 3%), although differences among fungal treatments were not statistically significant. Removals measured by GC-FID (TPH C8–C40) and by gravimetry ranked the treatments consistently. In the carbon mass balance, total fungal biomass was a minor carbon pool. The dual-strain consortium did not significantly outperform its individual strains. These results support native Amazonian WRF as promising bioaugmentation agents for mycoremediation of aged petroleum-contaminated soils and provide a foundation for future field-scale validation.