Regulation of chitinase synthesis in Trichoderma harzianum

Abstract

The production of chitinase by Trichoderma species is of interest in relation to their use in biocontrol and as a source of mycolytic enzymes. Fourteen isolates of the genus were screened to identify the most effective producer of chitinase. The best strain for chitinase was Trichoderma hurziunum 39.1, and this was selected for study of the regulation of enzyme synthesis. Washed mycelium of T. hurziunum 39.1 was incubated with a range of carbon sources. Chitinase synthesis was induced on chitin-containing medium, but repressed by glucose and Nacetylglucosamine. Production of the enzyme was optimal at a chitin concentration of 0.5 %, at 28 "C, pH 6.0 and was independent of the age of the mycelium. The synthesis of chitinase was blocked by both 8-hydroxyquinoline and cycloheximide, inhibitors of RNA and protein synthesis, respectively. The mode of chitinase synthesis in this fungus is discussed.

Isolation and Characterization of Trichoderma spp. for Antagonistic Activity Against Root Rot and Foliar Pathogens

“…In present investigation, it was found that chitinase and b-1,3-glucanase enzyme activities was increased with the substitution of specific carbon source at 1% concentration. These findings is in accordance with Ulhoa and Peberdy [25] where they suggested that chitinase activity was substrate's concentration dependent above 0.5% (w/v) chitin there was no further synthesis of chitinase in the growth medium by T. harzianum was increased up to 1% concentration, whereas b-1,3-glucanase enzyme production was increase up to 1% concentration of laminarin but decreased at higher concentrations. This may be due to the fact that at higher concentration of sugar activity of this enzyme was inhibited.…”

“…were grown in media supplemented with either autoclaved mycelium or purified host fungal cell walls [7,24]. Ulhoa and Peberdy [25] found that products of chitin degradation also …”

An Antifungal Exo-α-1,3-Glucanase (AGN13.1) from the Biocontrol FungusTrichoderma harzianum

“…These conditions have been described as "simulated antagonism" (13,14,30,45). These observations, together with the fact that chitin and ␤-1,3-glucan are the main skeletal polysaccharides of fungal cell walls (except those from Oomycetes, which contain ␤-glucans and cellulose) (3,34), suggest that chitinases and ␤-1,3-glucanases act as the key enzymes in the lysis of phytopathogenic fungal cell walls during the antagonistic action of Trichoderma.…”

Applications of Plackett–Burman and Central Composite Design for the Optimization of Novel Brevundimonas diminuta KT277492 Chitinase Production, Investigation of its Antifungal Activity

“…This method works on the concentration of N-acetyl glucosamine (NAG), which is released as a result of enzymatic action 22 . The 2mL reaction mixture contained 0.5 mL of 0.5% colloidal chitin in acetate buffer (pH 5.5), 0.5 mL crude enzyme extract and 1mL distilled water.…”