Determination of chitinase activity of Trichoderma isolates on colloidal chitin supplemented medium

Abstract

This study aimed to determine the chitinase activity of native Trichoderma spp. isolated from the southern part of Rajasthan on colloidal chitin supplemented medium. The isolates were screened for their antagonistic potential and ability to degrade chitin, a major component of fungal cell walls, by producing chitinase and β-1,3-glucanase enzymes. Chitinase activity was assessed through the formation of a purple halo zone on colloidal chitin agar, which correlates with the breakdown of chitin into N-acetylglucosamine (NAGA). A total of 21 Trichoderma isolates were screened, revealing a range of chitinase activities from low to high. Twelve isolates exhibited low chitinase activity, while seven isolates demonstrated high activity. The highest chitinase activity was observed in isolates Trichoderma harzianum BThr4, with 26.22 mg/ml NAGA released. Additionally, the β-1,3-glucanase activity was quantified, showing a significant variation among the isolates, with T. harzianum BThr29 exhibiting the highest enzyme activity (284.62 µg/ml). These findings support the potential use of Trichoderma isolates, particularly those with high chitinase and β-1,3-glucanase activity, in biocontrol applications against plant pathogens.