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 present invention describes a recombinant yeast cell functionally expressing one or more heterologous nucleic acid sequences encoding for ribulose-1,5-phosphate carboxylase/oxygenase (EC4.1.1.39; Rubisco), and optionally one or more molecular chaperones for Rubisco, and one or more phosphoribulokinase (EC2.7.1.19; PRK), wherein one or more genes of the non-oxidative branch of the pentose phosphate pathway are overexpressed and/or wherein said yeast cell comprises a deletion or disruption of a glycerol-3-phosphate dehydrogenase (GPD) gene.

The current disclosure provides a process for enzymatically converting a saccharide into allulose. The invention also relates to a process for preparing allulose where the process involves converting fructose 6-phosphate (F6P) to allulose 6-phosphate (A6P), catalyzed by allulose 6-phosphate 3-epimerase (A6PE), and converting the A6P to allulose, catalyzed by allulose 6-phosphate phosphatase (A6PP).

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 current disclosure provides a process for enzymatically converting a saccharide into allulose. The invention also relates to a process for preparing allulose where the process involves converting fructose 6-phosphate (F6P) to allulose 6-phosphate (A6P), catalyzed by allulose 6-phosphate 3-epimerase (A6PE), and converting the A6P to allulose, catalyzed by allulose 6-phosphate phosphatase (A6PP).

The present application relates to recombinant microorganisms useful in the biosynthesis of monoethylene glycol (MEG), or optionally MEG and one or more co-product, from one or more hexose feedstock. The present application also relates to recombinant microorganisms useful in the biosynthesis of glycolic acid (GA), or optionally GA and one or more co-product, from one or more hexose feedstock. The present application relates to recombinant microorganisms useful in the biosynthesis of xylitol, or optionally xylitol and one or more co-product, from one or more hexose feedstock. Also provided are methods of producing MEG (or GA or xylitol), or optionally MEG (or GA or xylitol) and one or more co-product, from one or more hexose feedstock using the recombinant microorganisms, as well as compositions comprising the recombinant microorganisms and/or the products MEG (or GA or xylitol), or optionally MEG (or GA or xylitol) and one or more co-product.

Provided are a 3-epimerase, an encoding polynucleotide therefor, a nucleic acid construct, vector, and host cell comprising the polynucleotide, a method for producing the 3-epimerase, and use of the 3-epimerase.

The invention relates to a cell capable of converting one or more pentose sugar and one or more hexose sugar into fermentation product constitutively expressing one or more heterologous or homologous polypeptide having the amino acid sequence set out in SEQ ID NO: 20, or a variant polypeptide thereof having at least 45% identity to SEQ ID NO 20. In an embodiment the heterologous polypeptide has glyoxalase activity.

This invention is aimed at improving an ethanol fermentation ability of a recombinant yeast strain having an ability of assimilating pentose, such as xylose or arabinose. The recombinant yeast strain haying an ability of assimilating pentose is obtained by lowering activity of a gene involved in upstream of glyceraldehyde-3-phosphate in the Embden-Meyerhof pathway.

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.