A combination of an electrochemical device for delivering reducing equivalents to a cell, and engineered metabolic pathways within the cell capable of utilizing the electrochemically provided reducing equivalents is disclosed. Such a combination allows the production of commodity chemicals by fermentation to proceed with increased carbon efficiency.

The present application provides genetically modified yeast cell comprising an active succinate fermentation pathway, as well as methods of using these cells to produce succinate.

The present disclosure relates to a genetically modified microorganism satisfying some of predetermined conditions. The predetermined conditions include: (I) succinate dehydrogenase activity or fumarate reductase activity being reduced or inactivated relative to a wild-type microorganism; (II) lactate dehydrogenase activity being reduced or inactivated relative to the wild-type microorganism; (III) the genetically modified microorganism having modified phosphoenolpyruvate carboxylase activity showing resistance to feedback inhibition by aspartic acid in wild-type phosphoenolpyruvate carboxylase activity, or exogenous phosphoenolpyruvate carboxylase activity having higher resistance to feedback inhibition by aspartic acid than that of the wild-type phosphoenolpyruvate carboxylase activity shown by the wild-type microorganism; and (IV) pyruvate:quinone oxidoreductase being reduced or inactivated relative to the wild-type microorganism.

Provided herein are microorganisms and methods for fermentative production of ß-ketoadipate from gaseous substrates such as carbon dioxide (CO.sub.2), carbon monoxide (CO), and/or hydrogen (H.sub.2). Additionally, the processes provided herein are methods for producing polymers containing ß-ketoadipate, that can potentially enable a circular economy by diverting waste, e.g., plastic waste.

The disclosure discloses an Aspergillus niger engineered strain for reducing byproduct succinic acid in a fermentation process of L-malic acid. The Aspergillus niger engineered strain is an Aspergillus niger engineered strain in which fumaric acid reductase frdA and fumaric acid reductase flavoprotein subunit frdB are simultaneously knocked out. The disclosure provides an frdA and frdB gene double-knockout Aspergillus niger strain, and a method for greatly reducing byproduct succinic acid in a fermentation process of L-malic acid. By the disclosure, the byproduct succinic acid accumulated in a production process of malic acid through fermentation of Aspergillus niger is significantly reduced, a cost in a downstream separation and purification process of malic acid is decreased, and good strains are provided for producing malic acid via industrial fermentation.

Provided herein are genetically modified Issatchenkia yeast and fermentation methods for producing succinic acid.

The present application provides genetically modified yeast cell comprising an active succinate fermentation pathway, as well as methods of using these cells to produce succinate.

Described are compositions and methods relating to modified yeast that overexpress fumarate reductase. The yeast cells have an increased fermentation rate compared to their parental cells. Such yeast cells are particularly useful for large-scale ethanol production from starch substrates where an increased rate of ethanol production is desirable.

A combination of an electrochemical device for delivering reducing equivalents to a cell, and engineered metabolic pathways within the cell capable of utilizing the electrochemically provided reducing equivalents is disclosed. Such a combination allows the production of commodity chemicals by fermentation to proceed with increased carbon efficiency.

Provided are a microorganism for producing a pantoic acid, and a construction method therefor and an application thereof. The microorganism for producing the pantoic acid is obtained by knocking out a gene in Escherichia coli and introducing an exogenous gene. The obtained microorganism is Escherichia coli that is registered in the China General Microbiological Culture Collection Center with an accession number of CGMCC No. 21699. A pantoic acid synthesis pathway has been opened up, and accumulation of the pantoic acid can be achieved in a fermentation process.