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.

Genetically engineered cells and methods are presented that enhance the consumption of xylose in a medium comprising a mix of five- and six-carbon sugars. Method of using these microbes to enhance xylose utilization and methods of making value products using these microbes are also disclosed herein.

The present invention provides an engineered cyanobacterium, comprising at least one plasmid selected from three novel pathways to produce acetate, which can convert atmospheric carbon dioxide as a raw material into acetate. The present invention also constructs the expression plasmid for three different transporters specific to acetate to be expressed in cyanobacteria, which comprises putative ABC transporter (AatA), succinate/acetate: proton symporter (SatP) and acetate/glycolate: cation symporter (ActP). Therefore, the engineered cyanobacteria of the present invention can produce 0.58 mg/L to 3.54 mg/L of acetate per hour.

The present invention relates to methods and recombinant microorganisms useful for the production of glycolic acid and/or glyoxylic acid. The methods of the invention involve either only one step of fermentation of the modified microorganisms of the invention or one step of fermentation of the modified microorganisms of the invention and one step of either biological or chemical conversion of the glycolic acid or of the glyoxylic acid, the microorganism of the invention over expressing a phosphoketolase gene.

Described are composition and methods relate to reducing the redox imbalance in anaerobically growing yeast with attenuated glycerol production by re-engineering the pathway for Ac-CoA biosynthesis.

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.

Described are recombinant microorganisms characterized by having phosphoketolase activity, having a diminished or inactivated Embden-Meyerhof-Parnas pathway (EMPP) by inactivation of the gene(s) encoding phosphofructokinase or by reducing phosphofructokinase activity as compared to a non-modified microorganism and having a diminished or inactivated oxidative branch of the pentose phosphate pathway (PPP) by inactivation of the gene(s) encoding glucose-6-phosphate dehydrogenase or by reducing glucose-6-phosphate dehydrogenase activity as compared to a non-modified microorganism. These microorganisms can be used for the production of useful metabolites such as acetone, isobutene or propene.

Aspects of the disclosure are directed to genetically modified yeast cells and methods for use. Certain aspects are directed to recombinant yeast cells comprising exogenous nucleic acid sequences encoding phosphotransacetylase and/or phosphoketolase proteins, including a phosphoketolase protein from Clostridium acetobutylicum. Also disclosed are methods for generating recombinant yeast cells and methods of use of such cells for production of one or more products, including lipids, oils, fatty acids, and triacylglycerides.

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.

Described are recombinant microorganisms characterized by having phosphoketolase activity, having a diminished or inactivated Embden-Meyerhof-Parnas pathway (EMPP) by inactivation of the gene(s) encoding phosphofructokinase or by reducing phosphofructokinase activity as compared to a non-modified microorganism and having a diminished or inactivated oxidative branch of the pentose phosphate pathway (PPP) by inactivation of the gene(s) encoding glucose-6-phosphate dehydrogenase or by reducing glucose-6-phosphate dehydrogenase activity as compared to a non-modified microorganism. These microorganisms can be used for the production of useful metabolites such as acetone, isobutene or propene.