渐狭蜡蚧菌产生的几丁质酶对芦笋茎枯病菌的抑制作用

目的:研究渐狭蜡蚧菌产生的几丁质酶及其对芦笋茎枯病菌天门冬拟茎点霉的抑制效果。方法:通过乙酰葡萄糖胺法、对硝基苯酚法和活性电泳法测定渐狭蜡蚧菌CGMCC5328的产几丁质酶特性及其粗酶液对芦笋茎枯病菌的抑菌效果。结果:渐狭蜡蚧菌CGMCC5328几丁质酶粗提取液的几丁质降解酶系活性第4 d达到高峰期;几丁质外切酶活性第6 d达到高峰期;活性染色检测到5条几丁质酶谱带,相对分子质量分别为32.9×103、42.1×103、54.1×103、65.6×103和79.6×103。用该几丁质酶粗酶液处理芦笋茎枯病菌,与灭活酶液处理相比较,抑菌效果明显,酶液处理导致菌丝畸形。结论:渐狭蜡蚧菌CGMCC5328产生的几丁质酶对芦笋茎枯病菌有抑制作用。

The Chitinases Produced by Lecanicillium attenuatum and its Inhibi tion Effect on Phomopsis asparagus

Objective: A study was conducted to investigate the chitinases from an antagonistic Lecanicillium at tenuatum CGMCC5328 and its inhibition on growth suppression of asparagus stem blight,Phomopsis asparagus.Methods: The chitinolytic systems and exochitinase of crude enzyme produced by L.attenuatum CGMCC5328 were measured by means of NAG,pNP and native staining respectively,and its antifungal potential against P.asparagus by plate inhibition assay.Results: The results showed that the activity of chitinolytic systems of filtrate from L.at tenuatum CGMCC5328 reached the highest level on the fourth day,and exochitinase activity on the sixth day.On SDS-PAGE analysis with 0.01% glycol chitin,five protein bands with chitinase activity were detected,relative mo lecular mass of 32.9×103,42.1×103,54.1×103,65.6×103 and 79.6×103,respectively.Mycelia in P.asparagus by crude chitinases of L.attenuatum CGMCC5328 exhibited sinificant suppression to that of heated enzyme,structural abnormality in mycelia was mediately by antibiosis.Conclusion: It is concluded that the chitinases produced by L.attenuatum CGMCC5328 plays an important role in the inhibition of P.asparagus.