Phlebiopsis gigantea is a basidiomycete belonging to a small group of microbes that are uniquely able to efficiently depolymerize, degrade, and mineralize lignin. Collectively referred to as white rot fungi, most are saprophytes that readily colonize hardwood substrates. Well-known examples previously sequenced by the Joint Genome Institute include Phanerochaete chrysosporium and Ceriporiopsis subvermispora. Although closely related to these species, the white rot fungus P. gigantea is distinct in its ability to rapidly colonize the freshly cut sapwood of conifers. The mechanisms by which this fungus degrades cell walls and the resinous components in conifer wood are poorly understood. This unusual capability has led to the development of P. gigantea as a biocontrol agent against subsequent colonization by the root rot pathogen Heterobasidium annosum and by blue stain fungi. Little is known about the mechanism(s) by which white rot fungi degrade conifer extractives, but it is expected that comparative genome analyses of P. gigantea and closely related polyporales such as P. chrysosporium, C. subvermispora and P. carnosa will advance our understanding of the complex hydrolytic and oxidative mechanisms involved in plant cell wall deconstruction, especially of conifer wood. Ultimately, these results may provide new strategies and enzymes that enable the efficient conversion of coniferous feedstocks to high value, small molecular weight products for the further development of bioenergy/biofuels processes.
