Study On Purification And Properties Of Chitinase From Ascosphaera Apis

Bee chalkbrood disease was a fungal epidemic disease of apian larva which was caused by Ascosphaera apis Olive&Spiltoir. Up to now , there were no effective methods to cure this disease. Under this conditions, this disease was still natural popular. Chitinase has a important role when pathogenetic fungi infected insects. One strain was selected from a total of ten stains Ascosphaera apis Olive & Spiltoir that could produce chitinase. The chitinase was purified , and its Properities was studied. After salt out of (NH4)₂SO₄, ion-exchange chromat-ography on DE-52 and Gel-filtration chromatography on Sephadex G-75, the fold was 6. 7. The chitinase exhibited optimum catalytic activity 40℃. It was retained above 40% activity between 35℃～45℃, but it was sensitive to high temperature; Its optimal pH was 7. 5, its activity could not be detected when pH below 4. 5 and above pH9. 0 its activity below 20%, and its activity was above 40% when pH between pH 6～9. When concentration between 1～100mmol/L, metal metal ions Na⁺,K⁺ enhanced the enzyme activity at first and then inhibited the enzyme activity. When concentration between 1～10mmol/L, Ca²⁺,Fe²⁺,Al³⁺ enhanced the enzyme activity, Mg²⁺,Mn²⁺ inhibited the enzyme activity, Zn²⁺,Fe³⁺ has no effect to the enzyme activity.