Elucidation of the regulatory network of Trichoderma reesei operating under cellulose-degrading conditions

Theresa Radebner 1 Franziska Wanka 1 Brigitte Gasser 2 Bernhard Seiboth 1
1Institute of Chemical, Environmental and Biological Engineering, TU Wien, Vienna, Austria
2Department of Biotechnology, BOKU University of Natural Resources and Life Sciences, Vienna, Austria

The ascomycete Trichoderma reesei is widely employed for the production of CAZymes (carbohydrate-active enzymes) which are of high importance for the production of second generation biofuels by hydrolysis of plant biomass. Hence, research of their production mechanisms as well as the investigation of their regulatory mechanisms on a cellular level is relevant from a scientific point of view and becomes even more important as the demand for plant derived biofuels is constantly growing.
By using available transcriptome data, we selected transcription factors and Gcn5-related acetylases that show an increased expression on wheat straw (inducing conditions) compared to glucose (repressing conditions) as we expect them to be directly or indirectly involved in the expression of CAZyme genes. We selected 13 candidate genes and their function was assessed by gene knock-out. Furthermore these deletion strains were characterized in terms of their phenotype, radial growth and cellulase production on different carbon sources as well as their behavior in the presence of different stressors.
We hope that this study will lead to a better understanding of the regulatory network under cellulose degrading conditions, thereby enabling a more fine-tuned manipulation of enzyme production in industrial settings of T. reesei.