Specificity Study Of Pinewood Nematode Cellulase

This experiment is a basic research focuses on the specificity of cellulase on diagnosis ofpine wood nematode (PWN) disease. PWN that separated from black pine and masson pine inZhejiang province was the main material in this study. I have compared enzyme activity andcharacter of PWN cellulase with fungi, in order to find the specificity of PWN cellulase. I thinkmy research can offer a good supply for considering cellulase as a specificity signal ondiagnosis of PWN disease.Accorading to the result of my research, cellulase excreted by pine wood nematode hasspecificity not only on enzyme activity but also on characters and molecular weight. The mainresults are summarized as follows:1. 307 isolates of fungi were obtained from the 26 samples of xylem collected from Pinusthunbergii, P. massoniana in Zhejiang province in which 158 isolates were identified asTrichoderma, Penicillium, Botryosphaeria, Pestalotia, Gliocladium, Aspergillus,Aureobasidium, Ceratocystis, Sphaeropsis, Acremonium. Trichoderma, Penicillium,Aspergillus and Botryosphaeria were dominant genus. The result of Congo-red pigmentationtest showed that pinewood nematode could excrete cellulase, and 96 isolates could excretecellulase, which belonged to Trichoderma, Penicillium and Aspergillus.2. Enzyme activity has no observably difference between PWN cellulase and fungi cellulaseexcept P. citrinum and P. variabile. (PWN cellulase: U_CX =0.256, U_Cl=0.210). The most suitablereaction temperature of PWN cellulase was 5℃lower than fungi cellulase, and pH of PWNCx enzyme was 1～1.5 units higher than fungi Cx enzyme. Besides, K⁺, Ba²⁺, Zn²⁺ and Al³⁺haddifferent effection to enzyme activity on both PWN cellulase and fungi cellulase. Themolecular weight of PWN cellulase were 29Kd (C_X)and 59Kd (C₁), these were bigger thanfungi cellulase.