Microorganism with modified hydrogenase activity
The invention provides genetically engineered microorganisms with modified hydrogenase activity and methods related thereto. Typically, the microorganisms are C1-fixing microorganisms with one or more disruptive mutations in a hydrogenase enzyme or a hydrogenase accessory enzyme. The microorganisms may have improved tolerance to toxins, such as acetylene, isocyanide, ammonium, or nitric oxide, improved production of products, such as ethanol, 2,3-butanediol, and isopropanol, and/or improved fixation of carbon, such as carbon derived from CO or CO 2 .
1. A genetically engineered C1-fixing microorganism comprising a disruptive mutation in an electron-bifurcating, NADP- and ferredoxin dependent [FeFe]-hydrogenase; wherein the electron-bifurcating, NADP- and ferredoxin dependent [FeFe]-hydrogenase is CAETHG_2794-99 (HytABCDE1E2) or a homologue thereof, wherein the microorganism is derived from Clostridium autoethanogenum, Clostridium ljungdahlii , or Clostridium ragsdalei.
2. The microorganism of claim 1 , wherein the CAETHG_2794-99 (HytABCDE1E2) comprises a disruptive mutation in one or more of subunits HytA, HytB, HytC, HytD, HytE1, and HytE2.
3. The microorganism of claim 1 , wherein the microorganism consumes a gaseous substrate comprising a C1-carbon source comprising CO 2 .
4. The microorganism of claim 1 , wherein the microorganism consumes a gaseous substrate comprising a C1-carbon source comprising CO.
5. The microorganism of claim 1 , wherein the microorganism is capable of net carbon capture.
6. A method of producing a product comprising culturing the microorganism of claim 1 in the presence of a gaseous substrate, whereby the microorganism produces the product, wherein the product is one or more of acetate, ethanol, and 2,3-butanediol.
7. The method of claim 6 , wherein the gaseous substrate comprises a C1-carbon source comprising CO 2 and/or CO.
8. A method of fixing carbon comprising culturing the microorganism of claim 1 in the presence of a gaseous substrate comprising a C1-carbon source, whereby the microorganism consumes more C1-carbon than it produces.
9. The method of claim 8 , wherein the gaseous substrate comprising the C1-carbon source comprises CO 2 and/or CO.
10. The method of claim 6 , wherein the microorganism produces more ethanol than a parental microorganism without the disruptive mutation.
11. The method of claim 7 or claim 9 , wherein the gaseous substrate further comprises H 2 .