Heterologous Expression of chi42 Gene from Trichoderma asperellum in Bacillus subtilis

Abstract

Chitinase is the enzyme that hydrolyzes chitin, a major component of fungal cell walls. This enzyme has the potential to be applied against certain phytopathogenic fungi for fruit preservation. Therefore, this study aimed to produce the extracellular 42 kDa chitinase of T. asperellum SH16 in B. subtilis BD170 (rCHI42) and evaluate preliminary its antifungal activity as the basis for further applications. The results showed that the chitinase activity of rCHI42 peaked at 27 U/mL after 8 h of Bacillus induction with 4 mM IPTG. The investigation revealed that rCHI42 had the optimum pH and temperature of 7 and 45°C, the pH and thermal stability were in the range of 6–8 and 25–35°C, respectively. Some metal ions (Fe2+, Al3+, Ca2+, and Mn2+) increased the relative activity of rCHI42 from 109 to 148%, while the enzyme was inhibited by most of the tested reagents (SDS, EDTA, urea, Triton X-100, and DMSO). rCHI42 also exhibited antifungal ability against phytopathogenic fungus Aspergillus niger which contains chitin in its cell wall. © 2021 Friends Science Publishers