Metabolic pathway engineering to increase production of ascorbic acid intermediates
AssigneeGenentech, Inc.
InventorsStephen Anderson, Robert A. Lazarus, Harvey I. Miller, R. Kevin Stafford
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Abstract
In recombinant microorganisms which were rendered capable of converting 2,5-diketo-D-gluconic acid (2,5-DKG) to 2-keto-L-gulonic acid (2-KLG) by transfer of genetic material, the secondary metabolites and metabolic pathways leading to the metabolic diversion of 2-KLG and 2,5-DKG were determined, and the diversion of 2-KLG to L-iodonic acid (IA) or of 2,5-DKG to 5-keto-D-gluconate (5-KDH) was blocked.
Claims12
A process for converting glucose to 2-keto-L-gulonic acid (2-KLG) comprising culturing in a medium containing said glucose under suitable metabolic conditions, 2,5-diketo-D-gluconic acid (2,5-DKG) producing bacterial cells to which genetic material was transferred wherein the transfer of said genetic material renders the cells capable of converting said 2,5-DKG into 2-KLG comprising
- a) identifying L-idonic acid (IA) and 5-keto-D-gluconate (5-KDG) as secondary metabolites and the corresponding secondary metabolic pathways, and the 2-ketoaldonate reductase (2-KR) enzymes catalyzing the conversions resulting in the metabolic diversion of 2-KLG to IA and 2,5-DKG to 5-KDG, and
- b) eliminating said metabolic diversion by blocking at least one of the identified secondary metabolites, secondary metabolic pathways, and enzymes.
A process for converting glucose to 2-KLG by culturing in a medium containing said glucose under suitable metabolic conditions, cells of bacterial strains selected from the group consisting of Acetobacter cerinus and Erwinia herbicola to which genetic material encoding a 2,5-DKG reductase enzyme was transferred, comprising eliminating the metabolic diversion of 2-KLG to IA or of 2,5-DKG to 5-KDG by blocking at least one of the secondary metabolites, secondary metabolic pathways and 2-KR enzymes resulting in said metabolic diversion.
Dependencies are inferred from the claim text.