吸水链霉菌应城变种的四个内源质粒及其逐个消除的研究

在改良质粒DNA提取方法的基础上,从三种农用抗生素的同一产生菌——吸水链霉菌应城变种中同时发现四个内源质粒,用双向电泳技术确定了它们均为CCC构型,根据分子量从大到小的顺序将它们分别命名为pHZ1、pHZ2、pHZ3和pHZ4,与已知分子量的CCC质粒分子同步电泳估计它们的分子量依次分别为61kb、4.7kb、4.1kb和3.3kb,基于这四个内源质粒中至少部分个体可能为接合性质粒,可在没有某个质粒的衍生菌株的菌坪上形成“麻点”的假设,我们分离和鉴定了三个质粒逐个消除的10-22衍生菌株,并在光学显微镜下确证了二种类型的麻点。

DETECTION OF FOUR PLASM1DS IN STREPTOMYCES HYGROSCOPICUS VAR. YINGCHENGENSIS 10-22 AND THEIR STEPWISE ELIMINATIONS

Four indigenous piasmids were detected with the medified method of plasmid DNA isolation in Streptomyces hygroscopicus var. yingchengensis 10-22, which produces three different effective antibiotics against plant diseases. Two dimentional agarose get electrophoresis revealed that all of them were Ccc molecales. By parallel electrophoresis with plasmids of known sizes, the four plasmds were estimated 10 be approximately 6' kb, 4. 7 kb, 4. 1 kb and 3. 3 kb in size, which were designated pHZ1 pHZ2. pHZ3 and pHZ4, respectively. Based on the assumption that conjugative plasmids would form "pocks" on the lawn of strains lacking corresponding plasmids, we isolated and characterized several 10-22 derivatives which had lose 13 plasmas, and confirmed tive types of pocks under light microscope.