Improving the simultaneous production of laccase and lignin peroxidase from Streptomyces lavendulae by medium optimization

To improve laccase (Lac) and lignin peroxidase (LiP) production from Streptomyces lavendulae, the Lac and LiP activity models were constructed and the C–N sources formulation in the medium optimal for the simultaneous production of Lac–LiP complex was asparagine 16.44%, urea 23.48%, fructose 18.01%, malt extract 21.21%, (NH4)2SO4 20.86%. By nutritional analysis, the optimal initial mole ratio of C/N for laccase and LiP production were 1.48, 1.43 with C, N levels of 1.298–1.308 mol L−1 and 0.875–0.912 mol L−1, respectively. Verification experiment revealed that the initial C/N ratio in medium was the key factor affecting laccase activity, and the combined C, N sources could improve ligninolytic enzymes activity. Thus, enzyme production cost could be cut down effectively, not only by the simultaneous fermentation of Lac–LiP complex, but also by maintaining the initial C/N mole ratio at 1.43–1.48 in the medium with low levels, and different kinds of C and N sources.