Fermentive production of four carbon alcohols
AssigneeButamax(Tm) Advanced Biofuels LLC
InventorsGail K. Donaldson, Andrew C. Eliot, Dennis Flint, Lori Ann Maggio-Hall, Vasantha Nagarajan
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Abstract
Methods for the fermentative production of four carbon alcohols is provided. Specifically, butanol, preferably isobutanol is produced by the fermentative growth of a recombinant bacterium expressing an isobutanol biosynthetic pathway.
Claims20
A recombinant yeast host cell comprising genes encoding an engineered isobutanol biosynthetic pathway, wherein said isobutanol biosynthetic pathway increases the production of isobutanol as compared to naturally occurring amounts of isobutanol made by unmodified yeast and comprises the following substrate to product conversions:
- (a) 2,3-dihydroxy-isovalerate to α-ketoisovalerate;
- (b) the α-ketoisovalerate from (a) to isobutyraldehyde;
- and
- (c) the isobutyraldehyde from (b) to isobutanol,
- wherein
- (i) the substrate to product conversion of step (a) is performed by a recombinantly expressed acetohydroxy acid dehydratase enzyme;
- (ii) substrate to product conversion of step (b) is performed by a recombinantly expressed decarboxylase enzyme;
- and
- (iii) the substrate to product conversion of step (c) is performed by a recombinantly expressed alcohol dehydrogenase enzyme,
- wherein the recombinantly expressed enzymes of (i) to (iii) are expressed in the cytosol, and wherein said recombinant yeast host cell is capable of producing isobutanol through the substrate to product conversions of (a) to (c).
Dependencies are inferred from the claim text.