Full text loading...
Chapter 87 : Proteomic Analysis of Extracellular Enzymes Produced by Wood-Degrading Fungi
This chapter reviews methods for proteomic analyses of white-rot fungi, which can degrade both the carbohydrate and the lignin components of wood to CO2. Microbial degradation of lignocellulosic material, due to the heterogeneity of the substrate, involves an ensemble of extracellular enzymes. Woody biomass has three major components: cellulose, hemicellulose, and lignin. Lignin is formed by free radical coupling of the phenylpropanoid units and thus can be linked by more than 12 types of linkages. Another group of wood-degrading Basidiomycetes, the brown-rot fungi, can also degrade fully lignified tissue but without substantial depletion of the lignin. Ascomycetes and Fungi Imperfecti cause the soft-rot type of wood decay which was categorized only within the past 30 years. The enzymes that utilize H2O2 and molecular oxygen to oxidize organic and inorganic substrates are the peroxidases and the laccases, respectively. Phenol extraction proved to be very effective in extracting plant proteins from interfering substances to obtain good resolution in 2-D gels. Methods are available for processing of the complete extracellular protein mixture by protease digestion and separation and identification by liquid chromatography and tandem mass spectrometry (MS-MS). For heavily glycoslyated proteins, CapLC–nanoelectrospray ionization–MS-MS can be used instead to analyze in-gel tryptic digests.