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US 2023/0183757 A1Published application
Methods and compositions for the production of xylitol from xylose utilizing dynamic metabolic control
AssigneeDuke University
InventorsMichael David Lynch, Shuai Li
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Abstract
The present disclosure is related to genetically engineered microbial strains and related bioprocesses for the production of xylitol. Specifically, the use of dynamically controlled synthetic metabolic valves to reduce the activity of certain enzymes, leads to increased xylitol production in a two-stage process.
Claims24
A genetically modified E. coli microorganism for producing xylitol from xylose comprising:
- a first gene expression-silencing synthetic metabolic valve or an enzymatic degradation synthetic metabolic valve to regulate expression of xylose reductase;
- a second gene expression-silencing synthetic metabolic valve or an enzymatic degradation synthetic metabolic valve to regulate expression of xylose isomerase;
- and
- a third gene expression-silencing synthetic metabolic valve or an enzymatic degradation synthetic metabolic valve to regulate expression of a gene that is not xylose reductase or xylose isomerase,
- wherein the genetically modified E. coli microorganism will produce xylitol in a biofermentation process comprising growing the genetically modified E. coli microorganism in a medium in a growth phase, transitioning to a productive stationary phase, the transition comprising:
- slowing or stopping microorganism growth, inducing the first gene expression-silencing synthetic metabolic valve or an enzymatic degradation synthetic metabolic valve to effect overexpression of xylose reductase, inducing the second gene expression-silencing synthetic metabolic valve or an enzymatic degradation synthetic metabolic valve to effect a reduction in xylose isomerase activity, and producing xylitol in the productive stationary phase.
3 more elements
A genetically modified E. coli microorganism for producing xylitol from xylose comprising:
- a first gene expression-silencing synthetic metabolic valve or an enzymatic degradation synthetic metabolic valve to regulate expression of xylose reductase;
- or
- a second gene expression-silencing synthetic metabolic valve or an enzymatic degradation synthetic metabolic valve to regulate expression of xylose isomerase
- wherein the genetically modified E. coli microorganism will produce xylitol in a biofermentation process comprising growing the genetically modified E. coli microorganism in a medium in a growth phase, transitioning to a productive stationary phase, the transition comprising:
- slowing or stopping microorganism growth, inducing the first gene expression-silencing synthetic metabolic valve or an enzymatic degradation synthetic metabolic valve to effect overexpression of xylose reductase or inducing the second gene expression-silencing synthetic metabolic valve or an enzymatic degradation synthetic metabolic valve to effect a reduction in xylose isomerase activity, and producing xylitol in the productive stationary phase.
2 more elements
-34. (canceled)
Dependencies are inferred from the claim text.