Heterologous expression and characterization of purified partial endochitinase (ech-42) isolated from Trichoderma harzianum

摘要

Chitinase gene from Trichoderma harzianum was cloned and hetrologously over expressed in M15 Escherichia coli. The recombinant protein of 42 kDa from E. coli was purified through Ni-NTA affinity column chromatography. The purified enzyme was active over broad range of pH (2.0 to 8.0) and temperature (10 to 60°C) with the peak activity at pH 5 (0.50 μg/ml) and 20°C with enzyme activity value (0.49 μg/ml). The purified protein fractions were tested for in vitro antifungal activity against different phytopathogens like Fusarium oxysporum f.sp. lycopersici, Sclerotioum rolfsii, Alternaria brassicae and Alternaria brassicicola. Purified endochitinase isolated from T. harzianum caused necrotic lesions, segmentation, branching and hyphal bursting at the concentration of 200 μg ml-1.