Production of Chitinase and β-1,3-glucanase by Trichoderma harzianum for Control of the Phytopathogenic Fungus Sclerotium rolfsii
M. H. El-Katatny1,2, W. Somitsch1, K.-H. Robra1, M. S. El-Katatny2 and G. M. Gübitz1*
1Department of Environmental Biotechnology, Graz University of Technology Petersgasse 12, A-8010, Graz, Austria
2Department of Botany, El-Minia University, El-Minia, Egypt
Article history:
Received March 24, 2000
Accepted May 17, 2000
Key words:
Trichoderma harzianum, chitinase, β-1,3-glucanase, antagonism, Sclerotium rolfsii, inhibition
Summary:
Twenty four isolates of Trichoderma were screened for β-1,3-glucanase and chitinase activity. Out of these organisms, a strain identified as T. harzianum Rifai secreted highest activities. In vitro production of chitinases and β-1,3-glucanases by T. harzianum, a mycoparasite of phytopathogenic fungi, was examined under various culture conditions. Enzymes production was significantly influenced by the carbon source incorporated into the medium and was stimulated by acidic pH from 5.5 to 6.0. Glucose or GlcNAc (0.5 %) addition along with chitin for chitinase and laminarin for β-1,3-glucanase, repressed production of these enzymes, while the polysaccharides as sole carbon source enhanced production of the respective enzymes. Production of both enzymes was also enhanced by polysaccharides contained in the mycelium of S. rolfsii. T. harzianum culture filtrates, possessing chitinase and β-1,3-glucanase activities, were capable of hydrolysing dried or fresh mycelium of the phytopathogenic fungus S. rolfsii. Growth of S. rolfsii was significantly inhibited (up to 61.8 %) by enzyme preparations from T. harzianum.
*Corresponding author:
++ 43 (0)316 8738 312
++ 43 (0)316 8738 815