β-1,3-glucanase production in Trichoderma isolates

β-glucan is a homopolymer of D-glucose residues which are linked through β-1,3 glycosidic bonds in the main chain. This polysaccharide, comprising the highest percentage of the fungal cell walls, has a major role in providing the cell wall with rigidity and protection. This is generally achieved through the assistance of other cell wall components, such as chitin and different proteins. β-glucanase enzymes degrade the polymer into its component residues by breaking the β-glycosidic bonds. As a producer of a variety of β-1,3 glucanase enzymes, the filamentous fungus Trichoderma, has become an important means of biological control for fungal diseases. In this study, after optimizing the glucanolytic conditions at both enzyme production and reaction stages for three randomly selected isolates, the glucanolytic activities of 30 Trichoderma isolates were assayed, leading to selection of the most and least active ones, T reesei with 22.07 U/mg and T. viridae 1 with 4.71 U/mg specific activity, respectively. In this regard, the T. reesei isolate, having the strongest β-1,3 glucanolytic activity among all isolates assayed, can be a nominee for further use as a biological control agent to protect against the fungal pathogens.