Patent ID: 7220588
Filing Date: 2007-05-22
Classification: C07K,C12N

Abstract:
1. A method of obtaining increased plasmid content in bacteria, said method comprising the steps of: a) introducing the plasmid into said bacteria; b) introducing a mutation in chromosomal gene rho of the bacteria; c) maintaining a functional copy of said chromosomal gene on a conditional replicon in said bacteria; d) culturing said bacteria under a condition permissive for intracellular replication and maintenance of said conditional replicon; e) culturing the bacteria under a restrictive condition that does not permit further intracellular replication of the conditional replicon; f) estimating the level of said plasmid in the bacteria cultured under both permissive and restrictive conditions; and g) comparing the level of said plasmid in the bacteria cultured under permissive and restrictive conditions, wherein a difference in the level of plasmid from bacteria cultured under permissive conditions and the level of plasmid from bacteria cultured under restrictive conditions is an indication of increased plasmid content, wherein the mutation in gene rho is a GC-to-TA transition mutation at codon 243 of the gene and the bacteria are E. coli.