【摘要】 以PEG沉淀法从庆丰链霉菌M-15菌株中分离到具有闭环和开环两种构型的质粒DNA,其分子量约为10×10~6道尔顿。以此质粒DNA作为供体,以质粒消除突变株A544制备原生质体作为受体,在40％聚乙二醇(PEG1000)的诱导下进行DNA转化。从实验结果获得的遗传性状来看,受体菌的表型由Pro~-→Pro~+、Sm~s→Sm~r、Qm~s→Qm~r,证明为转化子,并证明庆丰霉素合成是受质粒DNA控制的。更多还原

【Abstract】 Plassaid DNA was isolated from Streptomyces qingfengmyceticus M-15 using cleared lysate-PEG 6000 precipitation method. Its molecule has two configrations of cccDNA aadocDNA. The molecula. weight of plasmid DNA is about 10×10~8 dalton. We used plasmid DNA as donor, protoplast derived from A544 strain as recipient. Both were transformed under induced by PEG-1000, and transformants with different character were obtained. This experiment showed that qingfengmycin biosynthesis was controlled by plasmid.更多还原