The Charateristic Of Chitinase From Chaetomium Cupreum And The Inducement And Transformation Of Its Gene

The application of biological control is an important method of the synthesis control to plant diseases and insect pests and environment protection. It is also the the advantageous guarantee to the sustainable agriculture development.Through imitation the natural superparasitism process of C. cupreum, during which the six different disease fungus cell wall, colloid chitin, powder chitin and carboxymethyl chitosan are taken as the inducer repectively, we research on the effect of different time, different inducement to the production of chitinase from C. cupreum. The result shows that all different kinds of fungal cell wall, chitin and chitosan can induce the C. cupreum to produce chitinase; the chitinase activity induced by the cell wall of pathogenic fungus is higer than that of chitosan; the chitinase activty, induced by the R. solani, is higher than others', of which 25.44 U/mL. In contrast, the C. cupreum can not express the chitinase when iduced by P. sojae. Meanwhile, the peak activity and period of the chitinase are also different when it is induced by different inducement, which demonstrates that different inducement may induce different kinds of chitinase.The optimization temperature of chitinase induced by the cell-wall of X. oryzae, F. oxysparium, colloid chitin and powder chitin is 40℃; the chitinase has better thermal stability when the temperature is below 50℃; the optimiza-tion pH value of enzymatic reaction is pH5.0; it can keep good pH stability in the range of pH4.0-7.0. Denaturing agent and protease inhibitor have some depressant effect on the activity of chitinase, of which EDTA is most obvious. It also illustrates that the activity of chitinase depends on the metal ion.By the method of RT-PCR, we seprate the cDNA sequence of chi58 gene from the total RNA of C. cupreum and successfully link it with the expression vector pYES2 to construct the S. cerevisiae recombinatant expression vector pYES2-chi58. The recombinatant can express the protein in the ectocell which can reach the peak valuce 0.11 U/mL when induced for 60 h. Compared the chitinase activity of C. cupreum with that of chi58 gene in S. cerevisiae, the expression activity in C. cupreum is higher than that of chi58 gene in S. cerevisiae.Chitinase has the huge application potential in the biology controls and processes, and has become the current research focus. Researching and using chitinase thoroughly will give tremendous help to the people's production and life.