UBIQUITY OF LIGNIN-DEGRADING PEROXIDASES AMONG VARIOUS WOOD-DEGRADINGFUNGI

Phanerochaete chrysosporium is rapidly becoming a model system for the study of lignin biodegradation. Numerous studies on the physiology, b iochemistry, chemistry, and genetics of this system have been performe d. However, P. chrysosporium is not the only fungus to have a lignin-d egrading enzyme system. Many other ligninolytic species of fungi, as w ell as other distantly related organisms which are known to produce li gnin peroxidases, are described in this paper. In this study, we demon strated the presence of the peroxidative enzymes in nine species not p reviously investigated. The fungi studied produced significant mangane se peroxidase activity when they were grown on an oak sawdust substrat e supplemented with wheat bran, millet, and sucrose. Many of the fungi also exhibited laccase and/or glyoxal oxidase activity. Inhibitors pr esent in the medium prevented measurement of lignin peroxidase activit y. However, Western blots (immunoblots) revealed that several of the f ungi produced lignin peroxidase proteins. We concluded from this work that lignin-degrading peroxidases are present in nearly all ligninolyt ic fungi, but may be expressed differentially in different species. Su bstantial variability exists in the levels and types of ligninolytic e nzymes produced by different white rot fungi.