| Autor: |
Karp SG; Department of Bioprocess Engineering and Biotechnology, Federal University of Paraná, Coronel Francisco H. dos Santos Avenue, 210, 81531-990 Curitiba, PR, Brazil ; Biotechnology Program, Positivo University, Pedro Viriato Parigot de Souza Street, 5300, 81280-330 Curitiba, PR, Brazil., Faraco V; Department of Chemical Sciences, University of Naples 'Federico II', Monte S. Angelo University Complex, Via Cintia 4, 80126 Naples, Italy., Amore A; Department of Chemical Sciences, University of Naples 'Federico II', Monte S. Angelo University Complex, Via Cintia 4, 80126 Naples, Italy., Letti LA; Department of Bioprocess Engineering and Biotechnology, Federal University of Paraná, Coronel Francisco H. dos Santos Avenue, 210, 81531-990 Curitiba, PR, Brazil., Thomaz Soccol V; Department of Bioprocess Engineering and Biotechnology, Federal University of Paraná, Coronel Francisco H. dos Santos Avenue, 210, 81531-990 Curitiba, PR, Brazil., Soccol CR; Department of Bioprocess Engineering and Biotechnology, Federal University of Paraná, Coronel Francisco H. dos Santos Avenue, 210, 81531-990 Curitiba, PR, Brazil. |
| Abstrakt: |
Laccases are oxidative enzymes related to the degradation of phenolic compounds, including lignin units, with concomitant reduction of oxygen to water. Delignification is a necessary pretreatment step in the process of converting plant biomass into fermentable sugars. The objective of this work was to optimize the production of laccases and to evaluate the delignification of sugarcane bagasse by Pleurotus ostreatus in solid-state fermentation. Among eight variables (pH, water activity, temperature, and concentrations of CuSO4, (NH4)2SO4, KH2PO4, asparagine, and yeast extract), copper sulfate and ammonium sulfate concentrations were demonstrated to significantly influence laccase production. The replacement of ammonium sulfate by yeast extract and the addition of ferulic acid as inducer provided increases of 5.7- and 2.0-fold, respectively, in laccase activity. Optimization of laccase production as a function of yeast extract, copper sulfate, and ferulic acid concentrations was performed by response surface methodology and optimal concentrations were 6.4 g/L, 172.6 μM, and 1.86 mM, respectively. Experimentally, the maximum laccase activity of 151.6 U/g was produced at the 5th day of solid-state fermentation. Lignin content in sugarcane bagasse was reduced from 31.89% to 26.36% after 5 days and to 20.79% after 15 days by the biological treatment of solid-state fermentation. |
