A novel RpoD complementary system to stabilize plasmid and protein production in recombinant Escherichia coli

Abstract

An RpoD complementary system was constructed to increase the plasmid stability in Escherichia coli (E. coli). The E. coli strain carrying the rpoD285 mutation on its chromosome could not grow at high temperature without a plasmid containing the wild-type rpoD gene, and the selection was medium-independent in this system. To further examine this vector system, lacZ was cloned as recombinant DNA for the production of s-galactosidase, the lacZ gene product. Production from this system was approximately 1.9-fold higher than that of the wild-type strain carrying the plasmid.