Author(s): TAMIETTI, M. S.; MIDORIKAWA, G. E. O.; MENDES, T. D.; DAMASO, M. C. T.; BOM, E. P. S.; SILVA, A. S.; GOTTSCHALK, L. M. F.; NORONHA, E. F.; FAVARO, L. C. de L.

Summary: Carbon catabolite repression (CCR) is a mechanism by which microorganisms can utilize preferably highly energetic compounds over those of difficult degradation. For Trichoderma reesei, the protein that acts as repressor in the presence of glucose is CRE1. In this project, we aim to delete cre1 gene in Trichoderma harzianum CFAM-422 and obtain mutants with enhanced production of biomass degrading enzymes. Disruption of cre1 in T. harzianum CFAM-422 was performed by gene replacement of cre1 for hph (hygromycin B phosphotransferase) via homologous recombination. Hygromycin resistant mutants and parental strains enzyme production was evaluated in both inductive and repressive conditions in four different carbon sources. Enzymatic indexes (EI) were determined and compared. All genetically stable transformants showed increased enzymatic index under inductive conditions and modest inhibition under repressive conditions for most carbon sources, indicating that the deletion of cre1 in T. harzianum can be beneficial to cellulase and hemicellulase production with reduced product inhibition.

Publication year: 2017

Types of publication: Paper in annals and proceedings

Unit: Embrapa Food Technology

Keywords: Carbon Catabolite Repression, Cellulolytic and hemicellulolytic enzymes, Celulase, Processos de hidrolise enzimática de biomassa, Trichoderma Harzianum