Trichoderma spp. play an important role in the destruction of plant pathogenic
fungi, and were found to produce chitinase, which hydrolyzes chitin, a major
component of many pathogenic fungi cell walls. Out of four Trichoderma isolates,
Trichoderma harzianum T3 and T4 strains showed high chitinolytic activity on chitin -
basel agar medium. Factors involved the production of chitinase were investigated.
Maximum enzyme levels of ( 10 t015.9 U I ml) were achieved after six days
incubation at 28°C and initial pH of medium 6.5 The enzyme was produced only in the
presence of colloidal chitin at a concentration of 1 % (w/v) , as a sole carbon source,
suggesting the inducible nature of the enzyme. Trichoderma harzianum T 4 was found
to be very efficient to lyse mycelia of Microphomina phaseolina, Rhizoctonia solani
and Sclerotium rolfsii. Partial purification of chitinase from Trichoderma harzianum T4
was achieved by (NH₄)2 S04 precipitation followed by gel filtration using Sephadex G
- 200. The partially purified enzyme was found to be highly active at pH 6.5 and 50°C,
and thermostable at 50°C for 60 min. Mn2+ , Ca²+ and Fe²+ activated the enzyme,
whereas C0²+ , Cu²+ , Zn²+ and Hg2+ had different inhibitory effects.