Improved method for the expression of biotin in bacillus sphaericus.

摘要

The present invention relates to a method for the selection of organisms derepressed in the expression of primary or secondary metabolites, starting with a parent strain of this normally repressed organism, wherein: - said parent strain is transformed with a plasmid carrying a marker gene under the control of the DNA sequence involved in the regulation of the expression of said metabolite, - the strains thus transformed are subjected to a mutagenic treatment, and - the positive strains expressing said marker in the presence of said metabolite at a concentration totally repressing the expression of said marker in the transformed parent strain are selected, - from among these positive strains, the strains hyperproductive of metabolite are selected, optionally after they have been relieved of their plasmids.