| 摘要 |
The present invention relates to novel and useful cosmids for cloning and expressing the isolated DNA gene cluster which directs the synthesis of tetracycline and chlortetracycline, in a heterologous host such as Streptomyces lividans. The claimed plasmids (cosmids) are isolated by screening a cosmid library, constructed in Escherichia coli, for the expression of tetracycline resistance in S. lividans. Plasmids LP<2>127 and LP<2>128 are recovered from such tetracycline-resistant S. lividans isolates shown by HPLC analysis of agar and broth fermentations to direct the synthesis of tetracycline and chlortetracycline. |
