根癌病生防菌E26菌株产生细菌素的初步研究

A Bacteriocin with a Broad Spectrum Activity Produced by Grapevine Crown Gall Biocontrol Strain E26

根癌病是葡萄生产中的一种重要病害。葡萄土壤杆菌E26(Agrobacterium vitis E26)是葡萄根癌病的生防菌株,在平皿培养时能产生抑制根癌病菌生长的细菌素(土壤杆菌素E26)。本研究针对E26菌株产生土壤杆菌素的生物学性状进行研究,初步分离纯化了土壤杆菌素E26并且分析了其部分理化性质和生物学特性。E26菌株在pH 7.0的改良AB液体培养基中能够正常生长并产生对葡萄根癌病菌K308(A.vitis K308)有明显抑制作用的土壤杆菌素E26。用活性炭吸附和70%乙醇洗脱可以从发酵液中分离土壤杆菌素E26;再经过DEAE-Cellulose阴离子交换柱层析和CM-Cellulose阳离子交换柱层析可以部分纯化土壤杆菌素E26。土壤杆菌素E26在80℃处理30min和在室温pH 3.0～9.0处理1 h,抑菌活性均不受影响。部分纯化的土壤杆菌素E26不仅对来自葡萄和其它寄主的17株供试的根癌病菌有显著抑制作用,而且对茄科青枯病菌、番茄疮痂病菌、水稻白叶枯病菌、棉花细菌性角斑病菌和白菜软腐病菌也有抑制作用。

Agrobacterium vitis E26 is a biological control agent that suppresses crown gall, an important disease of grapevine caused by pathogenic strains of A.vitis. Strain E26 produces a bacteriocin (agrocin E26) toxic to pathogenic A. vitis on agar plate. In this study, biological properties of E26 associated with agrocin E26 production were investigated, and agrocin E26 was preliminarily purified and characterized. Incubated in a modified AB liquid medium with pH 7.0, strain E26 proliferated favorably and produced agrocin E26 inhibiting tumorgenic A.vitis strain K308 strongly in vitro. Agrocin E26 was partially purified from the culture broth and adsorbed by activated charcoal, extracted by 70% ethanol, ion exchange chromatography on DEAE-Cellulose and CM-Cellulose. Agrocin E26 was stable both at 80℃ for thirty minutes and pH 3.0 to 9.0 for one hour. Agrocin E26 exhibited strong inhibitory activity against tumorgenic bacteria isolates tested and showed inhibitory effects on Ralstonia solanacearum, Xanthomonas vesicatoria, X. oryzae pv. oryzae, X. campestris pv. malvacearum, and Erwinia carotovora subsp. carotovora at deferent levels.