Improved antifungal activity of a mutant of Trichoderma harzianum CECT 2413 which produces more extracellular proteins

Trichoderma harzianum is a well-known biological control agent against fung al plant diseases. In order to select improved biocontrol strains from Tric hoderma harzianum CECT 2413, a mutant has been isolated for its ability to produce wider haloes than the wild type, when hydrolysing pustulan, a polym er of beta -1,6-glucan. The mutant possesses between two and four times mor e chitinase, beta -1,3- and beta -1,6-glucanase activities than the wild ty pe, produces about three times more extracellular proteins and secretes hig her amounts of a yellow pigment (cc-pyrone). This mutant performed better t han the wild type during in vitro experiments, overgrowing and sporulating on Rhizoctonia solani earlier, killing this pathogen faster and exerting be tter protection on grapes against Botrytis cinerea.