Secretome analysis of Ganoderma lucidum cultivated in sugarcane bagasse

Abstract

Harmful environmental issues of fossil-fuels and concerns about petroleum supplies have spurred the search for renewable alternative fuels such as biofuel. Agricultural crop residues represent an abundant renewable resource for future biofuel. To be a viable alternative, a biofuel should provide a net energy gain, have environmental benefits, be economically feasible, and should also be producible in large quantities without reducing food supplies. We used these criteria to evaluate the white rot basidiomycota-derived fungus Ganoderma lucidum that secretes substantial amounts of hydrolytic and oxidative enzymes useful for the degradation of lignocellulosic biomass that were not described hitherto. The current bottleneck of lignocellulosic biofuel production is the hydrolysis of biomass to sugar. To understand the enzymatic hydrolysis of complex biomasses, we cultured G. lucidum with sugarcane bagasse as substrate and qualitatively analyzed the entire secretome. The secreted lignocellulolytic enzymes were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and diverse enzymes were found, of which several were novel lignocellulosic biomass hydrolyzing enzymes. We further explored G. lucidum-derived cellulose, hemicellulose and lignin degrading enzymes as valuable enzymes for the second generation of biofuel obtained from a lignocellulose substrate such as sugarcane bagasse.