Microorganisms for producing organic acids
Organic acid-producing microorganisms and methods of using same. The organic acid-producing microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid, acrylic acid, propionic acid, lactic acid, and others. Further modifications to the microorganisms increase production of such organic acids as 3-hydroxypropionic acid, lactate, and others. Methods of producing such organic acids as 3-hydroxypropionic acid, lactate, and others with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers are also provided.
1. A microorganism comprising:
a modification that reduces or ablates AcsA activity or AcsA homolog activity in the microorganism; and
one or more recombinant nucleic acids configured to express an enzyme selected from the group consisting of a malonyl-CoA reductase and a malonate semialdehyde reductase, wherein the microorganism produces an increased amount of 3-hydroxypropionic acid compared to a corresponding microorganism not comprising the one or more recombinant nucleic acids.
2. The microorganism of claim 1 wherein the microorganism is a bacterium.
3. The microorganism of claim 1 wherein the microorganism is a cyanobacterium.
4. The microorganism of claim 1 wherein the one or more recombinant nucleic acids is configured to express a malonyl-CoA reductase and a malonate semialdehyde reductase.
5. The microorganism of claim 1 wherein the one or more recombinant nucleic acids is configured to express a malonyl-CoA reductase from Sulfolobus tokodaii or a homolog thereof.
6. The microorganism of claim 5 wherein the malonyl-CoA reductase from Sulfolobus tokodaii or the homolog thereof comprises a sequence at least 80% identical to SEQ ID NO:13.
7. The microorganism of claim 5 wherein the malonyl-CoA reductase from Sulfolobus tokodaii or the homolog thereof comprises a sequence at least 90% identical to SEQ ID NO:13.
8. The microorganism of claim 5 wherein the malonyl-CoA reductase from Sulfolobus tokodaii or the homolog thereof comprises a sequence at least 95% identical to SEQ ID NO:13.
9. The microorganism of claim 1 wherein the one or more recombinant nucleic acids is configured to express a malonate semialdehyde reductase from Metallosphaera sedula or a homolog thereof.
10. The microorganism of claim 9 wherein the malonate semialdehyde reductase from Metallosphaera sedula or the homolog thereof comprises a sequence at least 80% identical to SEQ ID NO:16.
11. The microorganism of claim 9 wherein the malonate semialdehyde reductase from Metallosphaera sedula or the homolog thereof comprises a sequence at least 90% identical to SEQ ID NO:16.
12. The microorganism of claim 9 wherein the malonate semialdehyde reductase from Metallosphaera sedula or the homolog thereof comprises a sequence at least 95% identical to SEQ ID NO:16.
13. The microorganism of claim 1 wherein the microorganism is a bacterium, the one or more recombinant nucleic acids is configured to express a malonyl-CoA reductase from Sulfolobus tokodaii or a homolog thereof comprising a sequence at least 95% identical to SEQ ID NO:13 and a malonate semialdehyde reductase from Metallosphaera sedula or a homolog thereof comprising a sequence at least 95% identical to SEQ ID NO:16.
14. The microorganism of claim 13 wherein the microorganism is a cyanobacterium.
15. A method of producing 3-hydroxypropionic acid comprising culturing a microorganism as recited in claim 1 .
16. The method of claim 15 wherein the culturing produces 3-hydroxypropionic acid to a concentration of at least about 30 μM.
17. The method of claim 15 wherein the culturing produces 3-hydroxypropionic acid to a concentration of at least about 60 μM.