Mycoremediation potential and tolerance responses of Oudemansiella radicata in cadmium-pyrene co-contaminated soil

In recent years, many previous studies have well documented that wild and cultivated edible mushrooms have the ability to bioaccumulate metal ions, but the process of mycoremediation and the detoxification strategy of mushrooms in co-contaminants (heavy metals and polycyclic aromatic hydrocarbons (PAHs)) are rarely reported. The study was to investigate the mycoremediation potential and tolerance responses of Oudemansiella radicata in cadmium and pyrene co-contaminated soil. Soil samples collected and sieved from Sichuan province, China, which was spiked with cadmium (0, 5, 15, and 30 mg/kg) and pyrene (0, 200, and 400 mg/kg). After harvest, biomass, bioaccumulation of cadmium, residual pyrene, and antioxidant enzymes activities were measured. Results showed that dry biomass was not apparently influenced by the co-contamination, even in highly polluted soils. In cadmium of 5 and 15 mg/kg, the bioaccumulation of cadmium enhanced when pyrene was added, the bioconcentration factor value even reached 1.09. The removal of pyrene (added at concentrations of 200 and 400 mg/kg) was significantly higher in O. radicata-planted soils than those in the unplanted soils and was inhibited in lower level of cadmium whereas promoted in higher level of cadmium, indicating that the highly adapted cadmium-resistant microbes could promote the dissipation of pyrene. Besides, antioxidant enzyme activities including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) represented significantly changes in co-contamination as compared with control. Using O. radicata for remediation of cadmium-pyrene-contaminated soils could be an interesting alternative, considering its short life time, metal tolerance, and bioaccumulation capacity.