Bacterial strains, methods of preparing the same and use thereof in fermentation processes for L-lysine production
AssigneeArcher Daniels Midland Company
InventorsHungming J Liaw, John Eddington, Yueqin Yang, Richard Dancey, Stacia Swisher, Weiying Mao
Life of this patent
Estimating the term…
Abstract
The invention provides novel microorganisms, methods for the production thereof and novel processes for the production of amino acids. Mutagenesis of parental bacterial strains and selection of an improved raffinate-resistant phenotype enables the isolation of strains with enhanced growth properties that produce larger amounts of amino acid. Microorganisms of the invention are produced from amino acid producing parental strains such as Corynebacterium or Brevibacterium, particularly preferred are parental strains that produce L-lysine.
Claims6
A process for the production of L-lysine comprising culturing a raffinate-resistant bacterial strain B in a bacterial fermentation medium containing at least about 2% raffinate based on ammonium sulfate content, wherein said raffinate is the broth effluent waste stream product generated during the ion-exchange chromatographic purification of L-lysine, wherein said raffinate-resistant bacterial strain B is obtained by:
- (i) selecting a parental bacterial strain A that produces L-lysine;
- (ii) subjecting said parental bacterial strain A to mutagenesis;
- (iii) culturing the mutagenized parental bacterial strain A in a bacterial selection medium containing at least about 1% raffinate based on ammonium sulfate content, wherein said raffinate is the broth effluent waste stream product generated during the ion-exchange chromatographic purification of L-lysine;
- (iv) selecting said raffinate-resistant bacterial strain B from the bacterial selection medium containing said mutagenized parental bacterial strain A of part (iii), wherein said raffinate-resistant bacterial strain B is able to grow to a higher optical density at a wavelength of 660 nm than said parental bacterial strain A;
- (v) culturing said raffinate-resistant bacterial strain B in a bacterial fermentation medium containing at least about 2% raffinate based on ammonium sulfate content, wherein said raffinate is the broth effluent waste stream product generated during the ion-exchange chromatographic purification of L-lysine, wherein said bacterial strain B produces a higher amount of L-lysine compared to said parental bacterial strain A;
- and
- (vi) recovering the L-lysine from said bacterial fermentation medium.
Dependencies are inferred from the claim text.