解淀粉芽孢杆菌抗菌活性物质的分离纯化及抑菌活性研究

植物真菌病害给农业生产带来了巨大损失，因此对生物农药的开发迫在眉睫。从堆肥中分离得到一株解淀粉芽孢杆菌，它具有强烈的抗真菌活性。其发酵液经硫酸胺沉淀得到粗提液，粗提液经Hiprep 26/10 Desalting，HiLoad 26/10 Q Sepharose和HPLC多步柱层析，分离纯化得到一种抗真菌活性物质。ESI-MS质谱法测得其分子量为1498 Da。经活性检测发现，该纯物质对尖孢镰刀菌、草莓蛇病菌等植物病原真菌具有很强的抑制作用，对毛霉、黑曲霉等食品腐败菌也有抑制作用。经过显微镜观测，该物质可造成草莓蛇病菌菌丝生长异常，表现在菌丝弯曲，顶端膨大，分生孢子数量减少。

Purification and antifungal Characterization of an antifungal substance from Bacillus amyloliquifaciens

Fungal diseases of plant reduce yield and productivity of many economical crops.Chemical control of disease is costly both to the environment and to human.Therefore,screening antifungal bacteria for use in biological control becomes more important.Bacillus amyloliquifaciens isolated from the compost showed strong antifungal activity against a lot of plant pathogens.By ammonium sulphate precipitation,the crude extract was obtained from the culture medium of Bacillus amyloliquifaciens.Then it was isolated and purified by gel filtration on Hiprep 26/10 Desalting column,ion-exchange chromatography on HiLoad 26/10 Q Sepharose column.There are four fractions after the two steps above,and the third one was collected to be analyzed by HPLC.Eventually,three peaks were obtained,the second one which showed strong antifungal activity was collected as a pure substance.The molecular weight of it is 1498 Da as determined by ESI mass spectrometry.The pure substance shows strong inhibitory activity against Fusarium oxysporum f.sp.spinaciae O-27,Fusarium graminearium,Ramularia tulasnei Sacc and] Coniothyrium diplodiella.The abnormal hyphal growth of Ramularia tulasnei Sacc by the active substance such as twisted hypha,swollen tips was observed,in addition,the number of the conidia is less.