一株高漆酶活性树舌灵芝降解木质素条件的优化

Research on the Lignin-degrading Conditions Optimization of Ganoderma applanatum Strain with High Laccase Activity

以1株具有选择性降解木质素能力的树舌灵芝(Ganoderma applanatum)为基础菌株,通过液体发酵培养,对该菌株的木质素降解酶系进行初步分析,进而以木质素磺酸钙为底物,利用正交试验优化该菌株对木质素的降解条件.结果 表明,树舌灵芝可同时合成漆酶、锰过氧化酶和木质素过氧化物酶,其中漆酶活性显著高于锰过氧化酶和木质素过氧化物酶;经优化后,确定较适合树舌灵芝降解木质素的条件为:以3.0 g·L-1豆粕为氮源,底物浓度2.5 g·L-1,初始pH 6.0,发酵温度28℃,在此条件下木质素降解率达到44.72%.

In this study, a Ganoderma applanatum strain with lignin-degrading ability was used as a basic strain, and the ligni- nolytic enzymes of it was analyzed by liquid fermentation. Further, using calcium lignosulphonate as a substrate, lignin degrada tion conditions was optimized by orthogonal test. The results showed that, the G. applanatum strain could synthesize laccase, manganese peroxidase and lignin peroxidase simultaneously, and the activity of laccase was higher than that of the other two. The suitable lignin degradation condition for the G. applanatum strain was soybean meal 3.0 g·L^-1, the substrate concentration was 2.5 g·L^-1, initial pH was 6.0, and cultured under 28℃. Under these conditions, the lignin degradation rate reached 44.72%.