The disclosure provides genetically engineered microorganisms and methods for improved biological production of ethylene glycol and precursors of ethylene glycol. The microorganism of the disclosure produces ethylene glycol or a precursor of ethylene glycol through one or more of 5,10-methylenetetrahydrofolate, oxaloacetate, citrate, malate, and glycine. The disclosure further provides compositions comprising ethylene glycol or polymers of ethylene glycol such as polyethylene terephthalate.

The disclosure provides genetically engineered microorganisms and methods for improved biological production of ethylene glycol and precursors of ethylene glycol. The microorganism of the disclosure produces ethylene glycol or a precursor of ethylene glycol through one or more of 5,10-methylenetetrahydrofolate, oxaloacetate, citrate, malate, and glycine. The disclosure further provides compositions comprising ethylene glycol or polymers of ethylene glycol such as polyethylene terephthalate.

Methods and systems to control flexible gas fermentation platforms for improved conversion of CO.sub.2 into products is developed and particularly relates to a control process and system to control a ratio of feedstock gases and maximize the concentration of inert components in a bioreactor tail gas stream and or bioreactor headspace. Improved carbon utilization results though providing the most beneficial ratio of substrates to the bioreactor of the fermentation process.

The disclosure provides for the integration of a fermentation process with at least one electrolysis process, a CO.sub.2 to CO conversion unit, and a C1-generating industrial process. In particular, the disclosure provides process and a system for utilizing electrolysis products, for example H.sub.2 and/or O.sub.2 in a CO.sub.2 to CO conversion unit to improve the process efficiency of at least one of the fermentation processes or the C1-generating industrial process. More particularly, the disclosure provides a process in which H.sub.2 generated by electrolysis is passed to a CO.sub.2 to CO conversion unit to improve the substrate efficiency for a fermentation process, and the O.sub.2 generated by electrolysis process is used to improve the composition of the C1-containing tail gas generated by the C1-generating industrial process.

The disclosure provides methods to improve the economics of the gas fermentation process. A fermentation process is integrated with an industrial or syngas process and an reverse water gas shift process. An intermittent supply of reverse water gas shift process feedstock from the reverse water gas shift process is provided to the bioreactor for fermentation. The reverse water gas shift process feedstock may supplement or partially displace the C1 feedstock from the industrial or syngas process. Whether the reverse water gas shift process feedstock supplements or displaces the C1 feedstock may be based upon a function of the cost per unit of the C1 feedstock, the cost per unit of the reverse water gas shift process feedstock, and the value per unit of the fermentation product, or may depend upon the target gas ratio of the feedstock to the gas fermentation process.

An integrated process and system for the production of at least one gas fermentation product from a gaseous stream has been developed. The disclosure provides improved carbon utilization through both the recycle of a bioreactor tail gas via various different flow schemes and the employment of a CO.sub.2 to CO conversion system such as a reverse water gas shift unit. Recycling of the bioreactor tail gas and employment of a CO.sub.2 to CO conversion process provides for favourable H.sub.2:CO molar ratios of the feed to the gas fermentation bioreactor(s) for enhanced production of fermentation products. Bypass embodiments provide for optimal sizing of the reverse water gas shift unit to minimize cost.

Described herein are non-natural NAD.sup.+-dependent alcohol dehydrogenases (ADHs) capable of at least two fold greater conversion of methanol or ethanol to formaldehyde or acetaldehyde, respectively, as compared to its unmodified counterpart. Nucleic acids encoding the non-natural alcohol dehydrogenases, as well as expression constructs including the nucleic acids, and engineered cells comprising the nucleic acids or expression constructs are described. Also described are engineered cells expressing a non-natural NAD.sup.+-dependent alcohol dehydrogenase, optionally include one or more additional metabolic pathway transgene(s), methanol metabolic pathway genes, target product pathway genes, cell culture compositions including the cells, methods for promoting production of the target product or intermediate thereof from the cells, compositions including the target product or intermediate, and products made from the target product or intermediate.

Described herein are non-natural NAD.sup.+-dependent alcohol dehydrogenases (ADHs) capable of at least two fold greater conversion of methanol or ethanol to formaldehyde or acetaldehyde, respectively, as compared to its unmodified counterpart. Nucleic acids encoding the non-natural alcohol dehydrogenases, as well as expression constructs including the nucleic acids, and engineered cells comprising the nucleic acids or expression constructs are described. Also described are engineered cells expressing a non-natural NAD.sup.+-dependent alcohol dehydrogenase, optionally include one or more additional metabolic pathway transgene(s), methanol metabolic pathway genes, target product pathway genes, cell culture compositions including the cells, methods for promoting production of the target product or intermediate thereof from the cells, compositions including the target product or intermediate, and products made from the target product or intermediate.

The present invention concerns a new method for the production of 1,3-propanediol comprising culturing a recombinant microorganism converting glycerol into 1,3-propanediol and overexpressing the hcpR and/or frdX gene on a medium comprising glycerine. A recombinant microorganism for the production of 1,3 propanediol from glycerol, wherein said microorganism converts glycerol into 1,3-propanediol and 10 overexpresses the hcpR and/or the frdX gene.

The present invention concerns a new method for the production of 1,3-propanediol comprising culturing a recombinant microorganism converting glycerol into 1,3-propanediol and overexpressing the hcpR and/or frdX gene on a medium comprising glycerine. A recombinant microorganism for the production of 1,3 propanediol from glycerol, wherein said microorganism converts glycerol into 1,3-propanediol and 10 overexpresses the hcpR and/or the frdX gene.