Abstract: Polypeptides having ketol-acid reductoisomerase activity are provided. Also disclosed are recombinant host cells comprising isobutanol biosynthetic pathways employing such polypeptides. Methods for producing isobutanol employing host cells comprising the polypeptides having ketol-acid reductoisomerase activity are also disclosed.

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.

Abstract: Systems and processes for the production of fuel and fuel blends involve the production of fuels for blending with one or more alcohols such as ethanol and/or butanol. A method for producing a fuel blend includes blending a light distillate product from an oil refinery with butanol. The fuel blending can be at the oil refinery.

Abstract: The invention relates to a method for producing butanol through microbial fermentation, in which the butanol product is removed by extraction into a water immiscible organic extractant composition during the fermentation. The invention also relates to a method for producing butanol through microbial fermentation, in which the butanol product is removed during the fermentation by extraction into a water-immiscible extractant composition comprising a first solvent having a butanol partition coefficient of at least 3, and a second solvent having a butanol partition coefficient, wherein the butanol partition coefficient of the first solvent is higher than the butanol partition coefficient of the second solvent. Optionally, the first solvent has a higher concentration of hydrogen bonding sites than the second solvent. The invention further relates to a composition including butanol in the water immiscible organic extractant composition described above.

Abstract: From a bacterial strain isolated from an environmental sample, after enrichment in medium containing 1-butanol as the carbon source, a new enzyme with butanol dehydrogenase activity was identified. The enzyme can convert butyraldehyde to 1-butanol, isobutyraldehyde to isobutanol, as well as 2-butanone to 2-butanol and thus is useful for biosynthesis of butanol in recombinant microbial hosts producing these substrates. The encoding gene, named sadB, was isolated from the strain identified as an isolate of Achromobacter xylosoxidans.

Abstract: Provided herein are glycerol-3-phosphate dehydrogenase (GPD) enzymes with increased KM for NADH and GPD enzymes with substantially the same affinity for NADH and NADPH and/or are feedback inhibited by glycerol-3-phosphate. Also provided herein are recombinant microorganisms comprising a heterologous gene encoding GPD and a deletion or disruption in an endogenous gene encoding GPD. Also provided are recombinant microorganisms comprising a heterologous gene encoding GPD and a butanol biosynthetic pathway. Further provided are methods of producing butanol comprising providing the recombinant microorganisms described herein and contacting the recombinant microorganism with at least one fermentable carbon substrate under conditions wherein butanol is produced.

Abstract: Provided herein are recombinant yeast host cells and methods for their use for production of isobutanol. Yeast host cells provided comprise an isobutanol biosynthetic pathway and at least one of reduced or eliminated aldehyde dehydrogenase activity, reduced or eliminated acetolactate reductase activity; or a heterologous polynucleotide encoding a polypeptide having ketol-acid reductoisomerase activity.

Abstract: Provided herein are recombinant yeast host cells and methods for their use for production of isobutanol. Yeast host cells provided comprise an isobutanol biosynthetic pathway and at least one of reduced or eliminated aldehyde dehydrogenase activity, reduced or eliminated acetolactate reductase activity; or a heterologous polynucleotide encoding a polypeptide having ketol-acid reductoisomerase activity.

Abstract: The invention relates to suitable candidate alcohol dehydrogenase (ADH) enzymes for production of lower alkyl alcohols including isobutanol. The invention also relates to recombinant host cells that comprise such ADH enzymes and methods for producing lower alkyl alcohols in the same.

Abstract: The present invention relates to a catalytic process for making isooctenes using a reactant comprising isobutanol and water. The isooctenes so produced are useful for the production of fuel additives.

Abstract: Yeast cells with reduced activity of certain enzymes involved in branched chain amino acid biosynthesis in yeast mitochondria are described. Target enzymes include threonine deaminase, isopropylmalate synthase, and optionally branched chain amino acid transaminase.

Abstract: Provided herein are polypeptides having ketol-acid reductoisomerase activity as well as microbial host cells comprising such polypeptides. Polypeptides provided herein may be used in biosynthetic pathways, including, but not limited to, isobutanol biosynthetic pathways.

Abstract: Gasoline blends and methods for producing gasoline blends containing high concentrations of a butanol isomer and having good cold start and warm-up driveability characteristics are disclosed.

Abstract: In an alcohol fermentation process, oil derived from biomass is hydrolyzed into an extractant available for in situ removal of a product alcohol such as butanol from a fermentation broth. The glycerides in the oil can be catalytically (e.g., enzymatically) hydrolyzed into free fatty acids, which form a fermentation product extractant having a partition coefficient for a product alcohol greater than a partition coefficient of the oil of the biomass for the product alcohol. Oil derived from a feedstock of an alcohol fermentation process can be hydrolyzed by contacting the feedstock including the oil with one or more enzymes whereby at least a portion of the oil is hydrolyzed into free fatty acids forming a fermentation product extractant, or the oil can be separated from the feedstock prior to the feedstock being fed to a fermentation vessel, and the separated oil can be contacted with the enzymes to form the fermentation product extractant.

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.

Abstract: The invention relates to butanol compositions for fuel blending and fuel blends comprising such compositions. The compositions and fuel blends of the invention have desirable performance characteristics and can serve as alternatives to ethanol-containing fuel blends. The invention also relates to methods for producing such butanol compositions and fuel blends.

Abstract: Provided herein are recombinant yeast host cells and methods for their use for production of fermentation products from a pyruvate utilizing pathway. The yeast host cells provided herein comprise at least one genetic modification in a pyruvate decarboxylase gene and at least one genetic modification in an endogenous cell wall protein, which confers resistance to butanol and increased glucose utilization.

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.

Abstract: The present invention is related to a recombinant host cell, in particular a yeast cell, comprising a dihydroxy-acid dehydratase polypeptide. The invention is also related to a recombinant host cell having increased specific activity of the dihydroxy-acid dehydratase polypeptide as a result of increased expression of the polypeptide, modulation of the Fe—S cluster biosynthesis of the cell, or a combination thereof. The present invention also includes methods of using the host cells, as well as, methods for identifying polypeptides that increase the flux in an Fe—S cluster biosynthesis pathway in a host cell.

Abstract: Methods for the fermentive production of four carbon alcohols is provided. Specifically, butanol, preferably 1-butanol is produced by the fermentive growth of a recombinant bacterium expressing a 1-butanol biosynthetic pathway.