The host null who can containment the plasmid which possesses the gene which essential nutrient productivity the code is done in

摘要

NEW MATERIAL:A host, deficient in essential nutriment production ability, capable of introducing a plasmid having a gene coding the essential nutriment production ability, incapable of incorporating essential nutriments form the outside by active transport and capable of stably holding the plasmid having the gene coding the essential nutriment production ability. USE:Capable of stably holding a recombinant plasmid as a host. PREPARATION:A plasmid having a gene capable of coding essential nutriment production ability is introduced into a microorganism deficient in the essential nutriment production ability and screened to provide a microorganism, which is then subjected to variational treatment and screened. A strain from which the plasmid having the gene capable of coding essential nutriments is eliminated is screened from the resultant microorganism.