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: Methods for the fermentative production of isobutanol is provided by the fermentative growth of a recombinant microorganism expressing a highly active ketol-acid reductoisomerase enzyme in addition to other enzymes required for conversion of glucose to isobutanol.

Abstract: Provided herein are recombinant yeast host cells and methods for their use for production of fermentation products from a pyruvate utilizing pathway. Yeast host cells provided herein comprise reduced pyruvate decarboxylase activity and modified adenylate cyclase activity. In embodiments, yeast host cells provided herein comprise resistance to butanol and increased biomass production.

Abstract: The invention relates to recombinant host cells having at least one integrated polynucleotide encoding a polypeptide that catalyzes a step in a pyruvate-utilizing biosynthetic pathway, e.g., pyruvate to acetolactate conversion. The invention also relates to methods of increasing the biosynthetic production of isobutanol, 2,3-butanediol, 2-butanol or 2-butanone using such host cells.

Abstract: Crabtree positive yeast cells that have endogenous expressed pyruvate decarboxylase genes inactivated and an engineered biosynthetic pathway utilizing pyruvate were found to have improved growth and product yield when glucose repression was reduced. These cells were able to grow in media containing a high glucose concentration.

Abstract: Provided herein are processes comprising providing a fermentation medium comprising a fermentable carbon source, a recombinant microorganism comprising an engineered butanol biosynthetic pathway, and butanol; contacting said fermentation medium with an extractant composition comprising an effective amount of antioxidant or antioxidant-like compound, whereby at least a portion of the butanol in the fermentation medium partitions into the extractant; recovering at least a portion of the butanol and extractant composition from the fermentation medium; recycling the extractant composition recovered in (c) one or more times in the fermentation medium; optionally adjusting the effective amount of antioxidant or antioxidant-like compound in the extractant composition, whereby the rate of oxidation or effect of oxidized products in the recycled extractant composition is substantially reduced and/or avoided such that the extractant composition may be recycled.

Abstract: Provided herein are polypeptides and polynucleotides encoding such polypeptides which have ketoisovalerate decarboxylase activity. Also provided are recombinant host cells comprising such polypeptides and polynucleotides and methods of use thereof.

Abstract: Methods for the evolution of NADPH specific ketol-acid reductoisomerase enzymes to acquire NADH specificity are provided. Specific mutant ketol-acid reductoisomerase enzymes isolated from Pseudomonas that have undergone co-factor switching to utilize NADH are described.

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: The present invention is related to hydrocarbon compositions comprising butanol that have substantially the same or improved performance properties than comparable hydrocarbon compositions comprising ethanol and to methods for identifying such compositions.

Abstract: In an alcohol fermentation process, oil derived from biomass is chemically converted 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 chemically converted into a reaction product, such as fatty acids, fatty alcohols, fatty amides, fatty acid methyl esters, fatty acid glycol esters, and hydroxylated triglycerides, and mixtures thereof, which forms 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 chemically converting into the fermentation product extractant.

Abstract: Yeast strains were engineered that have increased activity of heterologous proteins that require binding of an Fe—S cluster for their activity. The yeast strains have reduced activity of an endogenous Fe—S protein. Activities of heterologous fungal or plant 2Fe-2S dihydroxy-acid dehydratases and Fe—S propanediol dehydratase reactivase were increased for increased production of products made using biosynthetic pathways including these enzymes, such as valine, isoleucine, leucine, pantothenic acid (vitamin B5), isobutanol, 2-butanone and 2-butanol.

Abstract: The invention relates to suitable screening strategies for evaluating various candidate promoters for differential gene expression during the propagation and production phases of a fermentation process. The invention also relates to recombinant host cells that comprise identified promoter nucleic acid sequences and methods for producing fermentation products employing the same.

Abstract: An alcohol fermentation process and composition that includes production of alcohol esters by esterification of product alcohol in a fermentation medium with a carboxylic acid (e.g., fatty acid) and a catalyst (e.g., lipase) capable of esterifying the product alcohol, such as butanol, with the carboxylic acid to form the alcohol esters. The alcohol esters can be extracted from the fermentation medium, and the product alcohol recovered from the alcohol esters. The carboxylic acid can also serve as an extractant for removal of the alcohol esters from the fermentation medium.

Abstract: An engineering method was developed to allow genetic modification and isolation of lactic acid bacteria cells that lack lactate dehydrogenase and acetolactate decarboxylase activities. In cells with these modifications and an isobutanol biosynthetic pathway, improved production of isobutanol was observed.

Abstract: Provided herein are polypeptides having ketol-aid 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: 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: 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: Provided herein are methods for recovering butanol from a fermentation medium. The methods comprise providing a fermentation medium comprising butanol, water, and a recombinant microorganism comprising a butanol biosynthetic pathway, wherein the recombinant microorganism produces butanol; contacting the fermentation medium with a water immiscible organic extractant composition comprising a dry solvent to form a butanol-containing organic phase and an aqueous phase; and recovering the butanol from the butanol-containing organic phase.

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.