Molecular characterization of beta-endoglucanase from antagonistic Trichoderma saturnisporum isolate GITX-Panog (C) induced under mycoparasitic conditions

摘要

The endoglucanase belonging to glycoside hydrolase family 61 are little studied. In present study, a beta-endoglucanase of similar to 37 kDa induced on autoclaved mycelium of Fusarium oxysporum was cloned and characterized. The molecular characterization of beta-endoglucanase encoding gene revealed presence of a single intron and an open reading frame of 1044-bp which encoded a protein of 347 amino acid residues. The phylogenetic analysis of Eglu revealed its similarity to endo-beta-glucanases of other Trichoderma spp. The catalytic site of beta-endoglucanase contained Asp, Asn, His and Tyr residues. The cDNA encoding beta-glucanase was cloned into E. coli and Pichia pastoris using pQUA-30 and pPIC9K vector system, respectively. The comparison of structure revealed that most similar structure to Eglu is Hypocrea jecorina template 5o2w.1.A of glycoside hydrolase family 61. The biochemical characterization of beta-endoglucanase purified from T. saturnisporum isolate and the recombinant protein expressed in E. coli and P. pastoris was active under acidic conditions with a pH optima of 5 and temperature optima of 60 degrees C. The purified and expressed enzyme preparation was able to inhibit growth of F.oxysporum at 1 X 10(5)spores/mL which clearly revealed its significance in plant pathogen suppression.