An Optimal Culture Medium for Laccase Production and Sugar Cane Vinasse Biotreatment with Trametes villosa Using Plackett-Burman and Central Composite Designs

Abstract

The optimal conditions for laccase production and vinasse biotreatment with a native strain of Trametes villosa were determined by a screening-optimization approach. Eleven factors including nutrient concentration, vinasse dilution (%v/v), inoculum volume, carbon to nitrogen ratio and initial pH, were investigated for their effects on laccase activity applying the Plackett-Burman screening design. The selected factors were optimized using a central composite design, and then evaluated on a vinasse biotreatment experiment. The factors that contributed the most to the enzymatic activity were the concentrations of MgSO₄∙7H₂O (A), FeSO₄∙7H₂O (B) and CuSO₄∙5H₂O (C), alongside initial pH.  After 10 days, laccase activity was 544.038 U L^-1 for the following concentrations of A, B and C: 0.250 g L^-1, 0.020 mg L^-1, and 0.100 g L^-1, respectively. Vinasse biotreatment under optimized conditions resulted in 82.74%, 78% and 75.97% of phenol, color, and COD removal respectively, while final pH value was 6.90. These results showed that the native strain of T. villosa has a good potential for further research on laccase production and vinasse sustainable management.