Application of T-DNA insertional mutagenesis for improving cellulase production in the filamentous fungus Trichoderma reesei

► A T-DNA-tagged mutant library of T. reesei was assayed for cellulase production. ► The mutants were characterized in cellulase production and hydrolysis performance. ► Several new genes possibly related to the cellulase production were isolated. ► T-DNA tagging is an effective strategy for improvement of cellulase production.