Effect of environmental C/N ratio on activities of lignin-degrading enzymes produced by Phanerochaete chrysosporium

Abstract

Lignin-degrading enzymes secreted by white rot fungi play an important role in the degradation of lignin and persistent organic pollutants (POPs). In this study, effect of environmental C/N ratio on the activities of lignin-degrading enzymes, lignin peroxide (LiP) and manganese peroxidase (MnP), produced by Phanerochaete chrysosporium, a white rot fungus, was investigated. Glucose was used as C source, and ammonium tartrate of different concentrations was used as N source to provide different C/N ratios. Relationships between LiP and MnP activities and environmental C/N ratio were explored. The results showed that the higher the N source concentration, the faster the mycelium pellets aged. The faster the mycelium dry weight increased, the higher the LiP and MnP activities. A high C/N ratio was a necessary condition for the secretion of LiP or MnP. In addition, mycelium dry weight essentially affected enzyme activities. In the 122 C/N ratio and 50 C/N ratio treatments, mycelium dry weight essentially affected MnP activity and both LiP and MnP activities, respectively.