Characterization of an amylase produced by a Trichoderma harzianum isolate with antagonistic activity against Crinipellis perniciosa, the causal agent of witches’ broom of cocoa

• Published in: FEMS microbiology letters 2000-07, Vol.188 (2), p.171-175
• Main Authors: de Azevedo, Aline M.C, De Marco, Janice L, Felix, Carlos R
• Format: Article
• Language: English
• Subjects: Amylases - chemistry; Amylases - isolation & purification; Amylases - metabolism; Amylopectin - metabolism; Antifungal Agents - chemistry; Antifungal Agents - isolation & purification; Antifungal Agents - metabolism; Biological and medical sciences; Biological control; Cacao - microbiology; Control; Crinipellis perniciosa; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; Fungal Proteins - chemistry; Fungal Proteins - isolation & purification; Fungal Proteins - metabolism; Fungi - metabolism; Fungi - pathogenicity; Glycogen - metabolism; Hydrogen-Ion Concentration; Maltose - analogs & derivatives; Maltose - metabolism; Oligosaccharides - metabolism; Phytopathology. Animal pests. Plant and forest protection; Starch - metabolism; Substrate Specificity; Temperature; Theobroma cacao; Trichoderma - enzymology; Trichoderma harzianum; Trisaccharides - metabolism; Witches’ broom
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1016/S0378-1097(00)00231-7

An isolate of Trichoderma harzianum showing antagonistic activity against Crinipellis perniciosa, the causal agent of the witches’ broom disease of cocoa, produces substantial amounts of hydrolytic enzymes. An amylase purified from isolate 1051 had a molecular mass of about 68.7 kDa. Maximal activity against soluble starch was determined at pH 4.0 and 60°C. The K m and V max values were 3.5 mg ml −1 and 1.67 mg min −1 of reducing sugar. The end products were mostly malto-oligosaccharides. The enzyme also hydrolyzed glycogen, amylopectin, maltotriose, and maltotetraose, but not pullulan or cellobiose. Maltose was only barely hydrolyzed. The purified amylase exerted a discrete hydrolytic effect on the C. perniciosa cell wall in vitro as observed by scanning electron microscopic analysis. While Fe 3+, Al 3+, Zn 2+, and Cu 2+ were effective in inhibiting the purified amylase, Mn 2+ considerably enhanced the activity. Ca 2+, Mg 2+, and Co 2+ showed no substantial effect on enzyme activity.