Abstract:
Lactic acid bacterial (LAB) cells were modified such that they have a specific activity of dihydroxy-acid dehydratase enzyme activity that is increased to about 0.1 µmol min -1 mg -1 . LAB cells with even higher activities of 0.2 to 0.6 µmol min -1 mg -1 of DHAD activity were obtained. These modified cells may be used to produce isobutanol when additional isobutanol biosynthetic pathway enzymes are expressed.
Abstract:
A group of bacterial dihydroxy-acid dehydratases having a [2Fe-2S] cluster was discovered. Bacterial [2Fe-2S] DHADs were expressed as heterologous proteins in bacteria and yeast cells, providing DHAD activity for conversion of 2,3-dihydroxyisovalerate to α-ketoisovalerate or 2,3-dihydroxymethylvalerate to α-ketomethylvalerate. Isobutanol and other compounds may be synthesized in pathways that include bacterial [2Fe-2S] DHAD activity.
Abstract:
Increasing tolerance to butanol in yeast has been accomplished by decreasing activity of Pdr5p encoded by an endogenous PDR5 gene. A deletion mutation of the PDR5 gene led to improved growth yield in the presence of butanol. Yeast cells with reduced Pdr5p activity, or other multidrug resistance ATP-binding cassette transporter protein activity encoded by CDR1 or BFR1, and a butanol biosynthetic pathway may be used for improved butanol production
Abstract:
[0070] A gasoline deposit control additive composition for use in a fuel comprising from about 70 to about 95 volume percent of hydrocarbons in the gasoline boiling range and from about 5 to about 30 volume percent of at least one alcohol, comprising the imine or tertiary amine product of the reaction between (a) at least one aldehyde or ketone or mixture thereof having the formula R 16 CHO, R 16 CH 2 CHO, R 17 (C=O) R 18 or R 17 CH 2 (C=O) R 18 , wherein R 16 , R 17 , and R 18 are the same or different and are each independently a straight or branched chain hydrocarbyl or aryl group that contains from 1 to 18 carbon atoms, and (b) a primary or secondary amine functionality.
Abstract:
A high flux of metabolites from pyruvate to 2,3-butanediol in Lactobacillus plantarum was achieved through genetic engineering. Substantial elimination of lactate dehydrogenase activity in the presence of heterologously expressed butanediol dehydrogenase activity led to 2,3 butanediol production that was at least 49% of the total of major pyruvate-derived products.
Abstract:
A method for producing butanol through microbial fermentation, in which the butanol product is removed by extraction into a water-immiscible extractant composition comprising a first solvent and a second solvent, is provided. The first solvent is selected from the group consisting of C 12 to C 22 fatty alcohols, C 12 to C 22 fatty acids, esters of C 12 to C 22 fatty acids, C 12 to C 22 fatty aldehydes, C 12 to C 22 fatty amides and mixtures thereof. The second solvent is selected from the group consisting of C 7 to C 11 alcohols, C 7 to C 11 carboxylic acids, esters of C 7 to C 11 carboxylic acids, C 7 to C 11 aldehydes, and mixtures thereof. Also provided is a method for recovering butanol from a fermentation medium.
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:
A microbial host cell is provided for the production of isobutanol. Carbon flux in the cell is optimized through the Entner-Doudorof pathway.