Why Sequence Trichoderma reesei Mutant strains?

Trichoderma reesei is the workhorse organism for a number of industrial enzyme companies for the production of cellulases. The costs associated with enzymes that degrade biomass are considered a bottleneck to economic lignocellulosic fuel ethanol. The DOE has made large investments in bioenergy research with the goal of economically viable cellulosic ethanol. One of the key barriers to a viable cellulosic fuel ethanol process emphasized by program offices within both DOE Office of Science and Energy Effiency and Renewable Energy is the cost of enzymes for the degradation of cellulosic biomass. Currently, the cellulases used in test and pilot cellulosic ethanol plants are produced by fungi, in many cases T. reesei. The widespread use of T. reesei in cellulase production underscores the importance of this organism and understanding the mechanisms behind enzyme secretion. This proposal lays a DNA sequence based foundation to tackle a current gap in industrial fungal enzyme production research: characterization of the cellular machinery behind enzyme secretion.

Academic and industrial research programs have over several years, through random mutagenesis, produced strains of T. reesei whose production of cellulases is several times higher than that of the “original” T. reesei cellulase producing strain, QM6a, isolated from US Army tent canvas in 1944 in the Solomon Islands. Understanding the molecular mechanisms that underlie the improvements made through random mutagenesis of T. reesei QM6a could lead to better and more efficient cellulase producing strains created through targeted molecular genetic manipulation rather than through a random mutagenesis process that leads to collateral and deleterious genome damage. In addition, sequencing one of its natural teleomorphs, which forms fruiting bodies in its habitat, will enable the identification of the genomic basis for meiosis in Trichoderma, which can subsequently be used to render the organism susceptible to classic genetic manipulation.

Principal Investigators: Scott E. Baker and Jon Magnuson (Pacific Northwest National Lab), Christian P. Kubicek (Tech. Univ. Vienna), Randy M. Berka (Novozymes), N. Jamie Ryding (Verenium), and Jan-Fang Cheng (DOE JGI)

Program: CSP 2009