06-08-2013, 04:43 PM
Enzyme profile of Trichoderma spp. isolated from soils of Jammu Division
ABSTRACT
Usage of Trichoderma spp. for the biological control of plant diseases is based to a large extent on secretion of their hydrolytic enzymes. The latter include chitinases and glucanases which degrade the cell wall of phytopathogenic fungi as well as the cuticle of insects and nematodes. The aim of this study was to assess the induction dynamics of chitinases and glucanases in ten isolates of Trichoderma. Among the Trichoderma spp. isolates, T5 and T7 showed highest activities. Chitinase and glucanase activity were evaluated at the first, third, sixth and ninth day of culture inoculation. The highest values of chitinase activity were obtained in basal and basal media supplemented with chitin; β- 1, 3-glucanase; on the other hand, exhibited higher levels of activity in basal and basal media supplemented with laminarin. Enzyme production was significantly influenced by the carbon source incorporated into the medium and was stimulated by acidic pH from 5.5 to 6.0. Production of both enzymes was also enhanced by polysaccharides contained in the mycelium of F. oxysporum. Culture filtrates possessing chitinase and β-1,3-glucanase activities were capable of hydrolysing fresh mycelium of the phytopathogenic fungus F. oxysporum.