Production of polyhydroxy alkanoates with a defined composition from an unrelated carbon source
Cells and methods for producing polyhydroxyalkanoates. The cells comprise one or more recombinant genes selected from an R-specific enoyl-CoA hydratase gene, a PHA polymerase gene, a thioesterase gene, and an acyl-CoA-synthetase gene. The cells further have one or more genes functionally deleted. The functionally deleted genes include such genes as an enoyl-CoA hydratase gene, a 3-hydroxyacyl-CoA dehydrogenase, and a 3-ketoacyl-CoA thiolase gene. The recombinant cells are capable of using producing polyhydroxyalkanoates with a high proportion of monomers having the same carbon length from non-lipid substrates, such as carbohydrates.
1. A recombinant cell for producing polyhydroxyalkanoate comprising a recombinant R-specific enoyl-CoA hydratase gene, a recombinant PHA polymerase gene, and a recombinant acyl-CoA-synthetase gene, wherein:
the recombinant cell is an E. coli;
gene products of genes fadR, fadA, and fadl; fadR, fadB, and fadJ; or fadR, fadA, fadI, fadB, and fadJ are functionally deleted due to genetic modifications of the genes;
the R-specific enoyl-CoA hydratase gene is a phaJ gene;
the PHA polymerase gene is a phaC gene; and
the recombinant cell is capable of producing polyhydroxyalkanoate.
2. The recombinant cell of claim 1 wherein gene products of genes fadR, fadA, and fadl are functionally deleted.
3. The recombinant cell of claim 1 wherein gene products of genes fadR, fadB, and fadJ are functionally deleted.
4. The recombinant cell of claim 1 wherein gene products of genes fadR, fadA, fadI, fadB and fadJ are functionally deleted.
5. The recombinant cell of claim 1 wherein the R-specific enoyl-CoA hydratase gene is phaJ3 and the PHA polymerase gene is phaC2.
6. The recombinant cell of claim 1 further comprising a recombinant thioesterase gene encoding an amino acid sequence at least about 80% identical to SEQ ID NO:20.
7. The recombinant cell of claim 1 wherein the recombinant acyl-CoA-synthetase gene encodes an amino acid sequence at least about 95% identical to SEQ ID NO:14.
8. The recombinant cell of claim 1 further comprising a recombinant phasin gene.
9. The recombinant cell of claim 1 further comprising a recombinant thioesterase gene, wherein the recombinant cell is capable of producing polyhydroxyalkanoate from carbohydrate in a medium devoid of a fatty acid source.
10. A method of producing polyhydroxyalkanoate comprising culturing a recombinant cell as recited in claim 1 .
11. The method of claim 10 comprising culturing the recombinant cell in aerobic conditions.
12. The method of claim 10 comprising culturing the recombinant cell in a medium comprising a carbohydrate and substantially devoid of a fatty acid source.
13. The method of claim 10 wherein the culturing produces polyhydroxyalkanoate to at least about 7.5% cell dry weight.
14. The method of claim 10 wherein the culturing produces polyhydroxyalkanoate comprised of hydroxyalkanoate monomers, wherein greater than about 50% of the hydroxyalkanoate monomers comprise hydrocarbon chains comprising same number of carbons.