Study On Properties And Metallic Ions Effects Of Monochamus Alternatus Hope Cellulase

Longicorn beetles are important wood-boring insect pests of trees, which feed on woody tissue causing weakness and death of the tree. Since the enzyme cellulase plays the major function to digest the ingested woody tissue in the intestines of longicorn pests, the study on the character and the degradation mechanism is expected to provide basic theories to sustainable management of the longicorn pests. Monochamus alternatus is one of the most perilous wood-boring insect pests in pinous plantations in southern China, In this paper, in lab and outdoor experiments were conducted to illustrate constitution, optimum reaction conditions ( temperature, pH and stability to heat ), kinetic parameters of cellulolytic enzyme on M. alternatus; the influence of metallic ions; the influence of fasting length, feeding time and etc, what's more, succession of cellulolytic enzyme on larvae of M. alternatus and research on oviposit of M. alternatus in filed also were studied.The cellulase extracted from larvae of M. alternatus was tested to determine its constitution and kinetic properties. The results revealed that the longicorn borers had integrated cellulolytic enzyme complex: endo - B - 1,4- glucanase (Cx - ase), exo - B -1, 4-glucanase (Ci-ase) and B-l, 4-glucosidase in their gut, also established the optimum temperature, pH . Besides, Cx-ase had the stronger stability to heat. After comparison of the kinetic parameters among the cellulases of M. alternatus, it was found that Q-ase had greater Vmax and Km, and, B-1,4-glucosidase had greater relatively muzzle velocity.Studies on eight kind of metallic ions (Cu2+ Fe2+. Mn2+ Ca2+ Pb2+ Ag+, Zn2+ 和 Na+)on cellulolytic enzyme of M. alternatus showed that metallic ions varied in effects on cellulase activity. Most of the metallic ions restrained whether in live conditions or in unorganized conditions while Fe2+ activated. Among which the Cu2+, Pb2+ were significant restrained strongly.The effect of feeding time, no-feeding time and others conditions on cellulase of M.alternatus showed cellulase activity increased in initially stage and then declined under the controlled conditions. At the same time, the cellulase activity is proportional to the abundance of twigs. Along with extend of the' feeding time, cellulase ( Cx -ase ,C1-ase and B - 1, 4 - glucosidase) activity of M. alternatus increased in initially stage and then declined, and then remained stabilization.Study on the activities of cellulolytic enzyme during larval development of M. alternatus and the variation in digestive activities indicated that the activities of Cx -ase and B - 1,4- glucosidase were conformed , comparatively, Changes of C1 - ase activities were very little on experiment conditions.Research on oviposit of M. alternatus indiceted that it's eggs were produced lasts mostly from July to August in field, and 7.13-7.23 were the top of the whole time.