Production of hydrocarbons in microorganisms
A recombinant microorganism employing a bacterial pathway to produce a cyclic amino acid (e.g., coronamic acid or norcoronamic acid) and a plant enzyme (ACC oxidase) to oxidize the amino acid and produce an alkene (e.g., 1-butene or propene) is provided herein. Expression of these two biosynthetic modules in various microbial chassis will facilitate alkene production from diverse energy and carbon sources, including sugars, glycerol, CO 2 , CH 4 , H 2 , and sunlight.
1. A recombinant prokaryotic microorganism of the genus Pseudomonas , comprising
a) one or more coronamic acid biosynthesis genes whose expression results in production of coronamic and/or norcoronamic acid; and
b) a gene encoding an 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase, wherein at least one of said genes is a recombinant gene and said microorganism-produces 1-butene or propene.
2. The recombinant microorganism of claim 1 , further comprising a gene encoding a β-cyanoalanine synthase and a gene encoding a nitrilase.
3. The recombinant microorganism of claim 1 , wherein said one or more coronamic acid biosynthesis genes are an L-isoleucine or L-valine isomerase and a coronamic acid synthase.
4. The recombinant microorganism of claim 2 , said microorganism further comprising a gene encoding an alanine dehydrogenase or a gene encoding a glutamate dehydrogenase.
5. The recombinant microorganism of claim 1 , said microorganism further comprising a recombinant gene that inhibits production of coronafacic acid, or a null mutation in a coronafacic acid pathway gene.
6. The recombinant microorganism of claim 4 , said microorganism further comprising a gene encoding a serine O-acetyl transferase.
7. The recombinant microorganism of claim 6 , said microorganism further comprising genes encoding GDP mannose synthase, GDP D mannose epimerase, GDP L galactose pyrophosphorylase, L-galactose dehydrogenase and L-galanolactone dehydrogenase.
8. The recombinant microorganism of claim 7 , said microorganism further comprising a gene encoding a threonine dehydratase or a gene encoding a homoserine dehydratase.
9. The recombinant microorganism of claim 8 , said microorganism further comprising a gene encoding a feedback resistant acetohydroxyacid synthase.
10. The recombinant microorganism of claim 9 , said microorganism further comprising a gene encoding a threonine deaminase, a gene encoding a citramalate synthase, or a gene encoding an isopropyl malate dehydrogenase.
11. A method of producing 1-butene or propene, comprising the steps of:
a) growing the recombinant microorganism of claim 1 in a culture medium, under conditions in which said coronamic acid biosynthesis genes and said ACC oxidase gene are expressed; and
b) recovering said 1-butene or propene produced by said microorganism.
12. The method of claim 11 , wherein said 1-butene or propene is recovered as a volatile product from gaseous components in the fermentor.
13. The method of claim 11 , wherein said culture medium comprises an inhibitor of coronafacic acid biosynthesis.
14. The method of claim 11 , wherein said culture medium comprises a compound selected from the group consisting of glycerol, glucose, xylose, CO 2 , H 2 and CH 4 .