Laccase activities of a soil fungus Penicillium simplicissimum in relation to lignin degradation

The laccase activities of Penicillium simplicissimum H5 during solid-state fermentation with rice straw were studied. Degradation of lignocellulose was also followed. Results showed that all supplemental carbon sources inhibited the laccase activity in different degrees, while suitable concentrations of supplemental nitrogen sources remarkably enhanced the laccase activity. The enhancement of activity by the ordinary laccase inducers 2, 2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) and xylidine was not observed in this study. Lignocellulose degradation was improved when laccase activity was relatively low, suggesting a polymerizing function of laccase in lignin degradation by P. simplicissimum.