Fungal lignin-modifying enzymes induced by vinasse mycodegradation and its relationship with oxidative stress

Vinasse, a byproduct waste from the ethanol industry, was used to cultivate Pleurotus sajor-caju and to evaluate the oxidative stress in term of antioxidant enzyme activity and its relation with the induction of laccase and manganese-peroxidase enzymes. Samples containing fungal enzyme extracts were analyzed and characterized by spectrophotometric and electrophoresis analysis. Results showed that the maximum fungal biomass production (11.7 g protein L−1) and laccase activity (424.9 IU L−1) were recorded on the 10th day, whereas manganese-peroxidase activity reached a maximum (100.9 IU L−1) on the 12th day of incubation. Based on the melanoidin degradation, the optimum vinasse decolorization (99.17%) was concomitant with an increase in laccase and manganese-peroxidase activity. Further, the increase in antioxidant enzyme activity such as superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR) indicated a vinasse-induced formation of reactive oxygen species (ROS). Thus, based on the results, the fungus P. sajor-caju can be applied for sugarcane wastewater treatment once this fungus resists to a stressful environment and maintains its homeostasis during vinasse biodegradation.