Improving production of laccase from novel basidiomycete with response surface methodology

Abstract

A Mycena purpureofusca strain screened from six basidiomycota fungi is well characterized in submerged fermentation for its high production of laccase and very low mycelium generation. Optimization of submerged fermentation medium for laccase production by M. purpureofusca was carried out with two statistical methods including Plackett-Burman (P-B) and Box-Behnken (B-B) designs. Three variables (sucrose, MgSO₄ and CuSO₄) were found to affect laccase production significantly by P-B screening. B-B design with three-factor at three levers was performed to explain the combined effects of the three medium constituents. The optimum medium consisted of sucrose (4.26 g/L), yeast powder (15 g/L), MgSO₄ (4.83 g/L), KH₂PO₄ (2.7 g/L), CuSO₄ (5.625 mg/L) and vitamin B1 (0.1 g/L). The laccase production was increased by 1.87 folds (277.5 U/L) using this optimized medium. Furthermore, the experimental value was closed to the prediction under the optimal condition, indicating that the chosen methods were successful to determine the optimal medium components, which is the least time consuming and most effective for laccase production. The data obtained in this study may provide new insights to large-scale laccase production by Mycena sp.

Key words: Mycena purpureofusca, Laccase, Medium optimization, Plackett-Burman design, Box-Behnken design