一株淡紫紫孢菌的分离、鉴定及生物学特性研究

Isolation,Identificat ion and Biological Characteristics of A Strain of Purpureocillium lilacinum

【目的】探究一株分离自柑橘粉虱座壳孢子座的淡紫紫孢菌在不同培养条件下的生长量、产蛋白酶和几丁质酶的活性,为淡紫紫孢菌作为生物防治剂提供理论基础。【方法】采用组织分离法将来自红江橙叶片粉虱座壳孢子座上的菌株进行分离纯化,结合形态学特性和分子生物学方法进行鉴定,并采用Folin-酚法和DNS法测定其蛋白酶和几丁质酶的活性。【结果】菌株ZJPL1812经形态学观察和ITS序列分析鉴定为淡紫紫孢菌(Purpureocillium lilacinum),菌株最佳培养温度为30℃、适宜pH值为5.0~9.0;以磷酸二氢铵为氮源、麦芽糖为碳源时最有利于菌丝生长,以蛋白胨为氮源、蔗糖为碳源时产蛋白酶活性最高,以硝酸铵为氮源、可溶性淀粉为碳源时几丁质酶活性最高。【结论】该菌株可以利用多种不同氮源、碳源,具有广泛的酸碱适应能力和较强的环境适应性,所产蛋白酶和几丁质酶活性较高,表明其具有一定的生物防治潜力。

【Objective】The study was conducted to investigate the growth,protease and chitinase activities of a strain of Purpureocillium lilacinum isolated from the stroma of Aschersonia aleyrodis on citrus under different culture conditions,with a view to providing a theoretical basis for the use of P.lilacinum as a biocontrol agent.【Method】The strains of the stroma of A.aleyrodis from Hongjiang orange leaves were isolated and purified by tissue isolation,identified by a combination of morphological characteristics and molecular methods,and their protease and chitinase activities were determined by the Folin-phenol and DNS method.【Result】The strain ZJPL1812 was identified as P.lilacinum by morphological observation and ITS sequence analysis.The best culture temperature for the strain was 30℃,and the suitable pH value was 5.0-9.0.The best mycelial growth was achieved when ammonium dihydrogen phosphate and maltose were used as the nitrogen and carbon sources;the highest protease activity was produced when peptone and sucrose were used as the nitrogen and carbon sources;and the highest chitinase activity was achieved when ammonium nitrate and soluble starch were used as the nitrogen and carbon sources.【Conclusion】The strain can use many different kinds of nitrogen and carbon sources,with a wide range of acid-base adaptability and strong environmental adaptability.And it produces high protease and chitinase activities,indicating that it has some potential in biological control.