Genetically engineered bacterium comprising energy-generating fermentation pathway
View Patent ↗The invention relates to a genetically engineered bacterium comprising an energy-generating fermentation pathway and methods related thereto. In particular, the invention provides a bacterium comprising a phosphate butyryltransferase (Ptb) and a butyrate kinase (Buk) (Ptb-Buk) that act on non-native substrates to produce a wide variety of products and intermediates. In certain embodiments, the invention relates to the introduction of Ptb-Buk into a C1-fixing microoorgansim capable of producing products from a gaseous substrate.
1. A genetically engineered bacterium comprising exogenous phosphate butyryltransferase (Ptb) and exogenous butyrate kinase (Buk) (Ptb-Buk), wherein the Ptb-Buk acts on a non-native substrate to produce a non-native product.
2. The bacterium of claim 1 , wherein the Ptb-Buk acts on a substrate other than butanoyl-CoA and/or butanoyl phosphate.
3. The bacterium of claim 1 , wherein the Ptb-Buk produces a product wherein the bacterium is C1-fixing bacterium other than butanoyl phosphate or butyrate.
4. The bacterium of claim 1 , wherein the bacterium does not produce butanol.
5. The bacterium of claim 1 , wherein the bacterium produces one or more of an acid, an alkene, a ketone, an aldehyde, an alcohol, or a diol.
6. The bacterium of claim 1 , wherein the bacterium produces one or more of acetone or a precursor thereof, isopropanol or a precursor thereof, isobutylene or a precursor thereof, 3-hydroxybutyrate or a precursor thereof, 1,3-butanediol or a precursor thereof, 2-hydroxyisobutyrate or a precursor thereof, adipic acid or a precursor thereof, 1,3-hexanediol or a precursor thereof, 3-methyl-2-butanol or a precursor thereof, 2-buten-1-ol or a precursor thereof, isovalerate or a precursor thereof, or isoamyl alcohol or a precursor thereof.
7. The bacterium of claim 1 , wherein the Ptb-Buk converts acetoacetyl-CoA to acetoacetate (step 2), 3-hydroxyisovaleryl-CoA to 3-hydroxyisovalerate (step 8), 3-hydroxybutyryl-CoA to 3-hydroxybutyrate (step 14), 2-hydroxyisobutyryl-CoA to 2-hydroxyisobutyrate (step 20), crotonyl-CoA to crotonate (step 28), acetobutyryl-CoA to acetobutyrate (step 33), or isovaleryl-CoA to isovalerate (step 44).
8. The bacterium of claim 1 , wherein the bacterium produces one or more of 1-propanol, 1-hexanol, and 1-octanol.
9. The bacterium of claim 1 , wherein the bacterium is derived from a parental bacterium selected from the group consisting of Clostridium autoethanogenum, Clostridium ljungdahlii, Clostridium ragsdalei, Escherichia coli, Saccharomyces cerevisiae, Clostridium acetobutylicum, Clostridium beijerinckii, Clostridium saccharbutyricum, Clostridium saccharoperbutylacetonicum, Clostridium butyricum, Clostridium diolis, Clostridium kluyveri, Clostridium pasterianium, Clostridium novyi, Clostridium difficile, Clostridium thermocellum, Clostridium cellulolyticum, Clostridium cellulovorans, Clostridium phytofermentans, Lactococcus lactis, Bacillus subtilis, Bacillus licheniformis, Zymomonas mobilis, Klebsiella oxytoca, Klebsiella pneumonia, Corynebacterium glutamicum, Trichoderma reesei, Cupriavidus necator, Pseudomonas putida, Lactobacillus plantarum , and Methylobacterium extorquens.
10. The bacterium of claim 1 , wherein the bacterium further comprises exogenous or endogenous aldehyde:ferredoxin oxidoreductase (AOR).
11. The bacterium of claim 1 , wherein the bacterium further comprises a disruptive mutation in a phosphotransacetylase (Pta) and an acetate kinase (Ack).
12. The bacterium of claim 1 , wherein the bacterium further comprises a disruptive mutation in a thioesterase.
13. A method of producing a product comprising culturing the bacterium of claim 1 in the presence of a substrate, whereby the bacterium produces the product.
14. The method of claim 13 , wherein the bacterium is derived from a parental bacterium selected from the group consisting of Clostridium autoethanogenum, Clostridium ljungdahlii, Clostridium ragsdalei, Escherichia coli, Saccharomyces cerevisiae, Clostridium acetobutylicum, Clostridium beijerinckii, Clostridium saccharbutyricum, Clostridium saccharoperbutylacetonicum, Clostridium butyricum, Clostridium diolis, Clostridium kluyveri, Clostridium pasterianium, Clostridium novyi, Clostridium difficile, Clostridium thermocellum, Clostridium cellulolyticum, Clostridium cellulovorans, Clostridium phytofermentans, Lactococcus lactis, Bacillus subtilis, Bacillus licheniformis, Zymomonas mobilis, Klebsiella oxytoca, Klebsiella pneumonia, Corynebacterium glutamicum, Trichoderma reesei, Cupriavidus necator, Pseudomonas putida, Lactobacillus plantarum , and Methylobacterium extorquens.
15. The method of claim 13 , wherein the bacterium produces one or more of acetone or a precursor thereof, isopropanol or a precursor thereof, isobutylene or a precursor thereof, 3-hydroxybutyrate or a precursor thereof, 1,3-butanediol or a precursor thereof, 2-hydroxyisobutyrate or a precursor thereof, adipic acid or a precursor thereof, 1,3-hexanediol or a precursor thereof, 3-methyl-2-butanol or a precursor thereof, 2-buten-1-ol or a precursor thereof, isovalerate or a precursor thereof, or isoamyl alcohol or a precursor thereof.
16. The method of claim 13 , wherein the Ptb-Buk converts acetoacetyl-CoA to acetoacetate (step 2), 3-hydroxyisovaleryl-CoA to 3-hydroxyisovalerate (step 8), 3-hydroxybutyryl-CoA to 3-hydroxybutyrate (step 14), 2-hydroxyisobutyryl-CoA to 2-hydroxyisobutyrate (step 20), crotonyl-CoA to crotonate (step 28), acetobutyryl-CoA to acetobutyrate (step 33), or isovaleryl-CoA to isovalerate (step 44).
17. The method of claim 13 , wherein the substrate is a gaseous substrate comprising one or more of CO, CO 2 , and H 2 .
18. The method of claim 13 , wherein the gaseous substrate is syngas or an industrial waste gas.