Roles of PKAc1 and CRE1 in cellulose degradation, conidiation, and yellow pigment synthesis in Trichoderma reesei QM6a

PurposeThis study aimed to reveal the roles of the protein kinase A catalytic subunit 1 (pkac1) and carbon catabolite repressor cre1 genes in cellulase production by Trichoderma reesei wild-type strain QM6a. Our strategy might be useful to construct a high-yielding cellulase strain for its wide application.MethodsThis paper describes cellulase activity, plate conidiation, and yellow pigment synthesis assays of QM6a with the disruption of pkac1 and cre1.ResultsDeletion of pkac1 (Δpkac1) had no effect on cellulase production or transcript levels of major cellulase genes in the presence of cellulose. Disruption of cre1 (Δcre1) resulted in a remarkable increase in cellulase production and expression of the four major cellulase genes. Double disruption of pkac1 and cre1 significantly improved enzyme activity and protein production. The double disruption also resulted in a significant reduction in yellow pigment production and abrogated conidial production.ConclusionDouble deletion of pkac1 and cre1 led to increased hydrolytic enzyme production in T. reesei using cellulose as a carbon source.