Enhanced laccase production by Trametes versicolor using corn steep liquor as both nitrogen source and inducer

•Corn steep liquor (CSL) enhanced laccase production by Trametes versicolor.•Sinapinic acid in CSL caused a reduction in laccase production.•Vanillic acid and ferulic acid in CSL synergistically induced laccase production. A highly efficient strategy for laccase production by Trametes versicolor was developed using corn steep liquor (CSL) as both a nitrogen source and a laccase inducer. At the optimal CSL concentration of 20gL−1, an extracellular laccase activity of 633.3UL−1 was produced after a culture period of only 5days. This represented a 1.96-fold increase relative to control medium lacking CSL. The addition of crude phenolic extracts from CSL improved laccase production to 91.8% greater than the control. Sinapinic acid, present in CSL, caused a reduction in laccase production, vanillic acid and ferulic acid (also present in CSL) synergistically induced laccase production by more than 100% greater than the control medium. Vanillic acid and ferulic acid provided the main contribution to the enhancement of laccase production. This study provides a basis for understanding the induction mechanism of CSL for laccase production.