White-rot basidiomycetes can degrade all components of lignocellulosic biomass, including lignin, cellulose and hemicellulose. Accordingly, harnessing the metabolic potential of these organisms will be key to developing cost-effective technologies for the production of renewable energy and value-added co-products from residual plant biomass.
The aim of the current initiative is to sequence the genome of the softwood-degrading, white-rot basidiomycete, Phanerochaete carnosa. While other white-rot species, including the model P. chrysosporium, have been mainly isolated from hardwoods, the majority of P. carnosa strains have been isolated from coniferous trees including Abies balsamea, Abies concolor, and Pinus ponderosa. Softwood and hardwood fiber differ in the structure and composition of their hemicellulosic polymers and lignin. For instance, glucuronoxylan comprises approximately 20-30 % of the secondary cell wall polysaccharides in hardwood, while galactoglucomannan is the main hemicellulose in secondary cell walls of softwood. Furthermore, softwoods contain mainly guaiacyl lignin, whereas hardwoods contain varying ratios of guaiacyl-syringyl lignins. Given its ability to efficiently grow on softwood substrates, it is anticipated that P. carnosa encodes enzymes that are comparatively proficient at processing this recalcitrant feedstock. The genome sequences from other basidiomycetous fungi will provide an important resource for comparative genomic analyses and construction of robust catabolic models to predict necessary activities for white-rot conversion of softwood fiber. Enzymes identified through these analyses are expected to be particularly important for bioproduct industries in Northern countries, where softwood constitutes a major portion of the available biomass.
Suzuki H, Macdonald J, Syed K, Salamov A, Hori C, Aerts A, Henrissat B, Wiebenga A, Vankuyk PA, Barry K, Lindquist E, Labutti K, Lapidus A, Lucas S, Coutinho P, Gong Y, Samejima M, Mahadevan R, Abou-Zaid M, de Vries RP, Igarashi K, Yadav JS, Grigoriev IV, Master ER. (2012) Comparative genomics of the white-rot fungi, Phanerochaete carnosa and P. chrysosporium, to elucidate the genetic basis of the distinct wood types they colonize. BMC Genomics. 13:444.