LIGNIN PEROXIDASES, MANGANESE PEROXIDASES, AND OTHER LIGNINOLYTIC ENZYMES PRODUCED BY PHLEBIA-RADIATA DURING SOLID-STATE FERMENTATION OF WHEAT-STRAW

The white rot fungus Phlebia radiata 79 (ATCC 64658) produces lignin p eroxidase (LiP), manganese peroxidase (MnP), glyoxal oxidase (GLOX), a nd laccase in the commonly used glucose low-nitrogen liquid medium. Ho wever, the enzymes which this fungus utilizes for selective removal of lignin during degradation of different lignocellulosic substrates hav e not been studied before. Multiple forms of LiP, MnP, GLOX, and lacca se were purified from P. radiata culture extracts obtained after solid -state fermentation of wheat straw. However, the patterns of extracell ular lignin-modifying enzymes studied were different from those of the enzymes usually found in liquid cultures of P. radiata. Three LiP iso forms were purified. The major LiP isoform from solid-state cultivatio n was LiP2. LiP3, which has usually been described as the major isoenz yme in liquid cultures, was not expressed during straw fermentation, N ew MnP isoforms have been detected in addition to the previously repor ted MnPs. GLOX was secreted in rather high amounts simultaneously with LIP during the first 2 weeks of growth, GLOX purified from P. radiata showed multiple forms, with pIs ranging from 4.0 to 4.6 and with a mo lecular mass of ca, 68 kDa.