Yi-guang W, Davies J E, Hutchinson C R
J Antibiot (Tokyo). 1982 Mar;35(3):335-42. doi: 10.7164/antibiotics.35.335.
Streptomyces erythreus NRRL 2338, the erythromycin producing microorganism, contains extrachromosomal (plasmid) DNA. Four different plasmids, pSE1, pSE2, pSE4 and pSE6 present in the wild-type strain have characteristic mobilities on agarose gel electrophoresis, molecular weight and restriction endonuclease digestion patterns. Treatment of the wild-type strain with ethidium bromide or acridine orange gave two variants, one that could not convert erythronolide B to 3 (alpha)-mycarosylerythronolide B and another than produced 2 approximately 3 times more erythromycin A than the parental strain. Although the plasmid DNA profile of these two variants is different from the wild-type strain, it is not possible to conclude that any of the structural genes for erythromycin biosynthesis are located on the plasmids of S. erythreus NRRL 2338.
红霉素产生菌红色链霉菌NRRL 2338含有染色体外（质粒）DNA。野生型菌株中存在的四种不同质粒pSE1、pSE2、pSE4和pSE6在琼脂糖凝胶电泳上具有特征性迁移率、分子量和限制性内切酶消化模式。用溴化乙锭或吖啶橙处理野生型菌株产生了两个变体，一个不能将红霉内酯B转化为3（α）-mycarosylerythronolide B，另一个产生的红霉素A比亲本菌株多约2至3倍。尽管这两个变体的质粒DNA图谱与野生型菌株不同，但无法得出红霉素生物合成的任何结构基因位于红色链霉菌NRRL 2338的质粒上的结论。
