Production of Trichoderma reesei cellulases on glucose-containing media

Abstract

The filamentous fungus Trichoderma reesei was shown to secrete active cellobiohydrolase I and the endoglucanase I catalytic core domain into the culture medium when the fungus was grown on glucose-containing medium. The expression of the proteins was driven by the promoters of the elongation factor 1 alpha, tef1, and the unidentified gene for cDNA1. The cDNA1 promoter gave the best yields. The highest amounts of cellobiohydrolase I and the endoglucanase I core, being 50 to 100 mg/liter, accounted for more than half of the total protein secreted by the fungus. The levels obtained with the tef1 promoter were 20 to 50 times lower.