A Trichoderma harzianum chitinase destroys the cell wall of the phytopathogen Crinipellis perniciosa, the causal agent of witches' broom disease of cocoa

A Trichoderma harzianum isolate (1051), which was able to antagonize in field the phytopathogen Crinipellis perniciosa, the causal agent of witches' broom disease of cocoa, produces several hydrolytic enzymes. A chitinase, with molecular mass of about 37 kDA, which was secreted by the Trichoderma in the culture medium containing chitin, was partially purified by gel filtration followed by hydrophobic chromatography. The optimal pH and temperature for chitin hydrolysis by the partially purified enzyme were 4.0 and 37 degrees C, respectively. Chitobiose, laminarin, cellulosic substrates including aryl-glucosides, xylan, starch and beta-galactomannan were not hydrolysed by the enzyme. Remarkably, the partially purified enzyme drastically affected the cell wall of the phytopathogen C. perniciosa in vitro.