The invention relates to an enzymatic method for producing 2-hydroxy-4-methylmercaptobutanoic acid from 3-methylthio-propanal (3-methylmercaptopropanal (MMP) or methional) and carbon dioxide.

Provided herein are compositions and methods for the fermentative production of 2,3-butanediol (2,3-BDO), compositions and methods for making methyl ethyl ketone (MEK), and methods of inducing drought tolerance in plants.

An acetic acid metabolizing ability of a recombinant yeast strain having xylose-metabolizing ability is to be improved. In such a recombinant yeast strain having xylose-metabolizing ability, the acetaldehyde dehydrogenase gene has been introduced and a gene encoding NADH dehydrogenase involved in reoxidation of cytoplasmic NADH on the mitochondrial outer membrane has been suppressed.

Provided herein are methods, compositions, and non-naturally occurring microbial organism for preparing compounds such as 1-butanol, butyric acid, succinic acid, 1,4-butanediol, 1-pentanol, pentanoic acid, glutaric acid, 1,5-pentanediol, 1-hexanol, hexanoic acid, adipic acid, 1,6-hexanediol, 6-hydroxy hexanoic acid, -Caprolactone, 6-amino-hexanoic acid, -Caprolactam, hexamethylenediamine, linear fatty acids and linear fatty alcohols that are between 7-25 carbons long, linear alkanes and linear -alkenes that are between 6-24 carbons long, sebacic acid and dodecanedioic acid comprising: a) converting a C.sub.N aldehyde and pyruvate to a C.sub.N+3 -hydroxyketone intermediate through an aldol addition; and b) converting the C.sub.N+3 -hydroxyketone intermediate to the compounds through enzymatic steps, or a combination of enzymatic and chemical steps.

The invention relates to engineering of acetyl-CoA metabolism in yeast and in particular to production of acetyl-CoA in a non-ethanol producing yeast lacking endogenous gene(s) encoding pyruvate decarboxylase and comprising a heterologous pathway for synthesis of cytosolic acetyl-CoA.

The present invention provides for a mechanism to completely replace the electron accepting function of glycerol formation with an alternative pathway to ethanol formation, thereby reducing glycerol production and increasing ethanol production. In some embodiments, the invention provides for a recombinant microorganism comprising a down-regulation in one or more native enzymes in the glycerol-production pathway. In some embodiments, the invention provides for a recombinant microorganism comprising an up-regulation in one or more enzymes in the ethanol-production pathway.

The invention provides non-naturally occurring microbial organisms containing a fatty alcohol, fatty aldehyde or fatty acid pathway, wherein the microbial organisms selectively produce a fatty alcohol, fatty aldehyde or fatty acid of a specified length. Also provided are non-naturally occurring microbial organisms having a fatty alcohol, fatty aldehyde or fatty acid pathway, wherein the microbial organisms further include an acetyl-CoA pathway. In some aspects, the microbial organisms of the invention have select gene disruptions or enzyme attenuations that increase production of fatty alcohols, fatty aldehydes or fatty acids. The invention additionally provides methods of using the above microbial organisms to produce a fatty alcohol, a fatty aldehyde or a fatty acid.

The disclosure discloses recombinant Pseudomonas plecoglossicida for producing L-xylose and application thereof, and belongs to the technical field of bioengineering. According to the disclosure, a synthesized 2-ketogluconate reductase gene and a 2,5-diketogluconate reductase gene derived from Corynebaterium ATCC 31090 and a pyruvate decarboxylase gene derived from Saccharomyces cerevisiae are successfully expressed in a host P. plecoglossicida by a double plasmid system, and an obtained genetically engineered strain is fermented for 56 h in a shake flask, where the yield of L-xylose reaches 16.2 g/L, and the transformation rate reaches 20.3%; the obtained genetically engineered strain is fermented for 48 h and 44 h in 3 L and 15 L fermentors, respectively, where the yields of L-xylose reach 37.6 g/L and 45.8 g/L, respectively, and the glucose transformation rates are 47.0% and 57.3%, respectively. The method has the advantages of low raw material cost, no pollution to the environment, simple operation, and important economic and social benefits.

The present invention relates to a transformant which uses Schizosaccharomyces pombe as a host into which a D-LDH gene derived from bacteria of the genus Pediococcus and a D-LDH gene derived from bacteria of the genus Lactobacillus are incorporated and in which some of the genes in a group of pyruvate decarboxylase-encoding genes of the Schizosaccharomyces pombe host have been deleted or inactivated.

Described herein are new approaches for the selection of S. cerevisiae strains with increased ethanol production from hydrolyzed starch derived sugars. An industrial production strain of Saccharomyces cerevisiae AS400 was subjected to positive selection of mutants resistant to toxic concentrations of oxythiamine, trehalose, 3-bromopyruvate, glyoxylic acid, and glucosamine. The selected mutants are characterized by 5-8% increase in ethanol yield (g g.sup.1 of consumed glucose) as compared to the parental industrial ethanol-producing strain. A multiple-step selection approach that consisted of the sequential selection using glyoxylic acid, glucosamine and bromopyruvate as selective agents resulted in a 12% increase in ethanol yield during fermentation on industrial media. These results indicate that the selection methods provided herein are useful for producing a variety of strains that are promising candidates for industrial ethanol production.