Mycoremediation of Petroleum-Contaminated Soil Using Native Ganoderma and Trametes Strains from the Ecuadorian Amazon

Petroleum-contaminated soils are a major environmental concern worldwide. In Ecuador, extensive oil spills in the Amazon have led to widespread hydrocarbon pollution, threatening ecosystems and posing health risks to nearby communities. Conventional remediation techniques are resource-intensive and may render soil unsuitable for future use. In contrast, mycoremediation-using fungi to degrade toxic contaminants-offers a sustainable alternative. White-rot fungi, known for their ligninolytic enzyme systems such as laccases and peroxidases, are capable of degrading a wide range of organic pollutants, including petroleum hydrocarbons. This study assessed the enzymatic activity of 16 fungal strains from the phyla Ascomycota and Basidiomycota isolated in the Ecuadorian Amazon. Plate-based screening and quantitative laccase activity assays confirmed positive enzymatic activity in all strains. The five strains with the highest enzymatic activity were Ganoderma cf. parvulum QCAM7791, Trametes menziesii QCAM7783, Trametes menziesii QCAM7788, Trametes menziesii QCAM7790, and Trametes meyenii QCAM7785, which were selected for a 60-day soil microcosm experiment under controlled laboratory conditions. These strains removed over 96% of total petroleum hydrocarbons from contaminated soil, demonstrating high biodegradation efficiency. These results highlight the promise of native fungal strains as bioremediation agents for petroleum-contaminated soils. Further studies should focus on evaluating their performance under field conditions and their potential integration into large-scale remediation strategies.