1. Patent Search
  2. Details

PROCESS FOR PRODUCING GLUTARATE AND GLUTARIC ACID METHYL ESTER

20170152531 ยท 2017-06-01

    Inventors

    Cpc classification

    International classification

    Abstract

    This document describes biochemical pathways for producing 2,4-pentadienoyl-CoA by forming one or two terminal functional groups, comprised of carboxyl or hydroxyl group, in a C5 backbone substrate such as glutaryl-CoA, glutaryl-[acp] or glutarate methyl ester. 2,4-pentadienoyl-CoA can be enzymatically converted to 1,3-butadiene.

    Claims

    1. A method of biosynthesizing glutarate methyl ester in a recombinant host, the method comprising enzymatically converting at least one of malonyl-[acp] and malonyl-CoA to glutarate methyl ester in said host using at least one polypeptide having malonyl-CoA O-methyltransferase activity and at least one polypeptide having thioesterase activity.

    2. The method of claim 1, wherein malonyl-[acp] is enzymatically converted to malonyl-[acp] methyl ester using said at least one polypeptide having malonyl-CoA O-methyltransferase activity.

    3. The method of claim 2, wherein malonyl-[acp] methyl ester is enzymatically converted to glutaryl-[acp] methyl ester using at least one polypeptide having an activity selected from the group consisting of synthase activity, dehydrogenase activity, dehydratase activity, and reductase activity.

    4. The method of claim 3, wherein glutaryl-[acp] methyl ester is enzymatically converted to glutarate methyl ester using said at least one polypeptide having thioesterase activity.

    5. The method of claim 1, wherein malonyl-CoA is enzymatically converted to malonyl-CoA methyl ester using said at least one polypeptide having malonyl-CoA O-methyltransferase activity.

    6. The method of claim 5, wherein malonyl-CoA methyl ester is enzymatically converted to glutaryl-CoA methyl ester using at least one polypeptide having an activity selected from the group consisting of synthase activity, -ketothiolase activity, dehydrogenase activity, hydratase activity, and reductase activity.

    7. The method of claim 6, wherein glutaryl-CoA methyl ester is enzymatically converted to glutarate methyl ester using said at least one polypeptide having thioesterase activity.

    8. The method of claim 1, wherein said polypeptide having malonyl-CoA O-methyltransferase activity has at least 70% sequence identity to the amino acid sequence set forth in SEQ ID NO:13.

    9. The method of claim 3 or 6, wherein said polypeptide having reductase activity has at least 70% sequence identity to the amino acid sequence set forth in SEQ ID NO: 11 or 12.

    10. The method of claim 1, said method further comprising enzymatically converting glutarate methyl ester to glutarate semialdehyde methyl ester in said host using at least one polypeptide having carboxylate reductase activity.

    11. The method of claim 1, further comprising enzymatically converting glutarate methyl ester to 5-oxopentanoic acid using at least one polypeptide having an activity selected from the group consisting of carboxylate reductase activity and esterase activity.

    12. The method of claim 10, further comprising enzymatically converting glutarate semialdehyde methyl ester to 5-hydroxypentanoic acid using at least one polypeptide having esterase activity.

    13. The method of claim 12, wherein the polypeptide having esterase activity has at least 70% sequence identity to the amino acid sequence set forth in SEQ ID NO:8.

    14. The method of claim 12, further comprising using at least one polypeptide having dehydrogenase activity to enzymatically convert glutarate semialdehyde methyl ester to 5-hydroxypentanoic acid.

    15. The method of claim 1, said method further comprising enzymatically converting glutarate methyl ester to glutaric acid using at least one polypeptide having esterase activity.

    16. The method of claim 15, said method further comprising enzymatically converting glutaric acid to 5-hydroxypentanoic acid using at least one polypeptide having carboxylate reductase activity and at least one polypeptide having dehydrogenase activity classified under EC 1.1.1.-.

    17. The method of claim 10 or 16, wherein the polypeptide having carboxylate reductase activity has at least 70% sequence identity to any one of the amino acid sequences set forth in any one of SEQ ID NOs: 2-7.

    18. The method of claim 1, wherein the polypeptide having thioesterase activity has at least 70% sequence identity to any one of the amino acid sequences set forth in SEQ ID NO: 9, 10, 14 or 15.

    19. The method of claim 16, further comprising enzymatically converting 5-hydroxypentanoic acid to 2,4-pentadienoyl-CoA using at least one polypeptide having an activity selected from the group consisting of CoA-transferase activity, a synthase activity, and dehydratase activity.

    20. The method of claim 19, wherein (i) a polypeptide having a CoA-transferase activity or a synthase activity and (ii) a polypeptide having dehydratase activity enzymatically convert 5-hydroxypentanoic acid to 2,4-pentadienoyl-CoA.

    21. The method of claim 19, further comprising enzymatically converting 2,4-pentadienoyl-CoA into 1,3 butadiene using at least one polypeptide having an activity selected from the group consisting of hydratase activity, thioesterase activity, decarboxylase activity, dehydrogenase activity, CoA-transferase activity, and dehydratase activity.

    22. The method of claim 21, wherein the polypeptide having thioesterase activity has at least 70% sequence identity to any one of the amino acid sequences set forth in SEQ ID NOs: 14-15.

    23. A method of making glutarate, said method comprising (i) enzymatically converting glutaryl-[acp] methyl ester to glutaryl-[acp] or glutaryl-CoA methyl ester to glutaryl-CoA using a polypeptide having pimeloyl-[acp] methyl ester methylesterase activity, and (ii) enzymatically converting glutaryl-[acp] or glutaryl-CoA to glutarate using at least one polypeptide having thioesterase activity, reversible CoA-ligase activity, a CoA-transferase activity, an acylating dehydrogenase activity, an aldehyde dehydrogenase activity, a glutarate semialdehyde dehydrogenase activity, or a succinate-semialdehyde dehydrogenase activity.

    24. The method of claim 23, wherein said polypeptide having pimeloyl-[acp] methyl ester methylesterase activity has at least 70% sequence identity to the amino acid sequence set forth in SEQ ID NO: 1.

    25. The method of claim 23, wherein glutaryl-[acp] or glutaryl-CoA is enzymatically converted to glutaric acid using a polypeptide having thioesterase activity or a polypeptide having reversible CoA-ligase activity or a CoA-transferase activity.

    26. (canceled)

    27. The method of claim 23, wherein glutaryl-[acp] or glutaryl-CoA is enzymatically converted to glutaric acid using a polypeptide having an acylating dehydrogenase activity, an aldehyde dehydrogenase activity, a glutarate semialdehyde dehydrogenase activity, or a succinate-semialdehyde dehydrogenase activity.

    28. The method of claim 1, wherein the host is subjected to a cultivation strategy under aerobic or micro-aerobic cultivation conditions; wherein the host is cultured under conditions of nutrient limitation either via nitrogen, phosphate or oxygen limitation; and/or wherein the host is retained using a ceramic membrane to maintain a high cell density during fermentation

    29-30. (canceled)

    31. The method of claim 1, wherein a principal carbon source fed to the host is derived from a biological feedstock or a non-biological feedstock.

    32. The method of claim 31, wherein the biological feedstock is, or derives from monosaccharides, disaccharides, lignocellulose, hemicellulose, cellulose, lignin, levulinic acid and formic acid, triglycerides, glycerol, fatty acids, agricultural waste, condensed distillers' solubles, or municipal waste and the non-biological feedstock is, or derives from, natural gas, syngas, CO.sub.2/H.sub.2, methanol, ethanol, benzoate, non-volatile residue (NVR) or a caustic wash waste stream from cyclohexane oxidation processes, or terephthalic acid/isophthalic acid mixture waste streams.

    33-34. (canceled)

    35. The method of claim 1, wherein the host is a prokaryote.

    36. The method of claim 35, wherein the prokaryote is selected from the group consisting of Escherichia; Clostridia; Corynebacteria; Cupriavidus; Pseudomonas; Delftia; Bacilluss; Lactobacillus; Lactococcus; and Rhodococcus.

    37. The method of claim 36, wherein the prokaryote is selected from the group consisting of Escherichia coli, Clostridium ljungdahlii, Clostridium autoethanogenum, Clostridium kluyveri, Corynebacterium glutamicum, Cupriavidus necator, Cupriavidus metallidurans. Pseudomonas fluorescens, Pseudomonas putida, Pseudomonas oleavorans, Delftia acidovorans, Bacillus subtillis, Lactobacillus delbrueckii, Lactococcus lactis, and Rhodococcus equi.

    38. The method of claim 1, wherein the host is a eukaryote.

    39. The method of claim 38 wherein the eukaryote is selected from the group consisting of Aspergillus, Saccharomyces, Pichia, Yarrowia, Issatchenkia, Debaryomyces, Arxula, and Kluyveromyces.

    40. The method of claim 39, wherein the eukaryote is selected from the group consisting of Aspergillus niger, Saccharomyces cerevisiae, Pichia pastoris, Yarrowia lipolytica, Issathenkia orientalis, Debaryomyces hansenii, Arxula adenoinivorans, and Kluyveromyces lactis.

    41. The method of claim 1, wherein the host exhibits tolerance to high concentrations of a C5 building block, and wherein the tolerance to high concentrations of a C5 building block is improved through continuous cultivation in a selective environment.

    42. The method of claim 1, wherein said host expresses one or more of the following exogenous polypeptides having an acetyl-CoA synthetase, a 6-phosphogluconate dehydrogenase; a transketolase; a feedback resistant threonine deaminase; a puridine nucleotide transhydrogenase; a formate dehydrogenase; a glyceraldehyde-3P-dehydrogenase; a malic enzyme; a glucose-6-phosphate dehydrogenase; a fructose 1,6 diphosphatase; a propionyl-CoA synthetase; a L-alanine dehydrogenase; a L-glutamate dehydrogenase; a L-glutamine synthetase; a lysine transporter; a dicarboxylate transporter; and/or a multidrug transporter activity.

    43. The method of claim 1, wherein the host comprises an attenuation of one or more polypeptides having an activity selected from the group consisting of: polyhydroxyalkanoate synthase, an acetyl-CoA thioesterase, an acetyl-CoA specific -ketothiolase, an acetoacetyl-CoA reductase, a phosphotransacetylase forming acetate, an acetate kinase, a lactate dehydrogenase, a menaquinol-fumarate oxidoreductase, a 2-oxoacid decarboxylase producing isobutanol, an alcohol dehydrogenase forming ethanol, a triose phosphate isomerase, a pyruvate decarboxylase, a glucose-6-phosphate isomerase, a transhydrogenase dissipating the cofactor imbalance, aglutamate dehydrogenase specific for the co-factor for which an imbalance is created, a NADH/NADPH-utilizing glutamate dehydrogenase, a pimeloyl-CoA dehydrogenase; an acyl-CoA dehydrogenase accepting C5 building blocks and central precursors as substrates; a glutaryl-CoA dehydrogenase; and a pimeloyl-CoA synthetase.

    44. A recombinant host cell comprising at least one exogenous nucleic acid encoding a polypeptide having malonyl-CoA O-methyltransferase activity; and a polypeptide having thioesterase activity, the host producing glutarate methyl ester.

    45. The host of claim 44, the host further comprising: an exogenous polypeptide having carboxylate reductase activity, said host further producing glutarate semialdehyde methyl ester; one or more exogenous polypeptides having an activity selected from the group consisting of synthase activity, dehydrogenase activity, dehydratase activity, and reductase activity; and/or one or more exogenous polypeptides having an activity selected from the group consisting of synthase activity, -ketothiolase activity, dehydrogenase activity, hydratase activity, and reductase activity.

    46-47. (canceled)

    48. The host of claim 44, wherein the polypeptide having malonyl-CoA O-methyltransferase activity has at least 70% sequence identity to the amino acid sequence set forth in SEQ ID NO:13.

    49. The host of claim 44, wherein the polypeptide having thioesterase activity has at least 70% sequence identity to any one of the amino acid sequences set forth in any one of SEQ ID NOs: 14-15.

    50. The host of claim 45, wherein the polypeptide having reductase activity has at least 70% sequence identity to any one of the amino acid sequences set forth in SEQ ID NOs: 11 or 12.

    51. The host of claim 44, the host further comprising an exogenous polypeptide having esterase activity, the host further producing glutaric acid or 5-oxopentanoic acid.

    52. The host of claim 44, the host comprising one or more exogenous polypeptides having an activity selected from the group consisting of esterase activity, 6-hydroxyhexanoate dehydrogenase activity, 4-hydroxybutyrate dehydrogenase activity, 5-hydroxypentanoate dehydrogenase activity, and alcohol dehydrogenase activity, the host producing 5-hydroxypentanoic acid.

    53. The host of claim 52, further comprising one or more exogenous polypeptides having an activity selected from the group consisting of CoA-transferase activity, a synthase activity, and dehydratase activity, the host producing 2,4-pentadienoyl-CoA from 5-hydroxypentanoic acid.

    54. The host of claim 53, further comprising one or more exogenous polypeptides having an activity selected from the group consisting of hydratase activity, thioesterase activity, decarboxylase activity, dehydrogenase activity, CoA-transferase activity, and dehydratase activity, the host producing 1,3-butadiene from 2,4-pentadienoyl-CoA.

    55. The host of claim 54, wherein said polypeptide having thioesterase activity has at least 70% sequence identity to the amino acid sequence set forth in SEQ ID NO: 14 or SEQ ID NO: 15

    56. The host of claim 45, wherein the polypeptide having carboxylate reductase activity has at least 70% sequence identity to any one of the amino acid sequences set forth in any one of SEQ ID NOs: 2-7.

    57. A recombinant host comprising at least one exogenous nucleic acid encoding a polypeptide having pimeloyl-[acp] methyl ester methylesterase activity, and at least one polypeptide having an activity selected from the group consisting of thioesterase activity, reversible CoA-ligase activity, a CoA-transferase activity, an acylating dehydrogenase activity, an aldehyde dehydrogenase activity, a glutarate semialdehyde dehydrogenase activity, and a succinate-semialdehyde dehydrogenase activity.

    58. The recombinant host of claim 57, wherein said polypeptide having pimeloyl-[acp] methyl ester methylesterase activity has at least 70% sequence identity to the amino acid sequence set forth in SEQ ID NO: 1.

    59. A bio-derived product, bio-based product or fermentation-derived product, wherein said product comprises: i. a composition comprising at least one bio-derived, bio-based or fermentation-derived compound according to claim 1, or any one of FIGS. 1-7, or any combination thereof, ii. a bio-derived, bio-based or fermentation-derived polymer comprising the bio-derived, bio-based or fermentation-derived composition or compound of i., or any combination thereof, iii. a bio-derived, bio-based or fermentation-derived resin comprising the bio-derived, bio-based or fermentation-derived compound or bio-derived, bio-based or fermentation-derived composition of i. or any combination thereof or the bio-derived, bio-based or fermentation-derived polymer of ii. or any combination thereof, iv. a molded substance obtained by molding the bio-derived, bio-based or fermentation-derived polymer of ii. or the bio-derived, bio-based or fermentation-derived resin of iii., or any combination thereof,

    Description

    DESCRIPTION OF DRAWINGS

    [0083] FIG. 1 is a schematic of exemplary biochemical pathways leading to glutarate methyl ester or glutaryl-[acp] from malonyl-[acp].

    [0084] FIG. 2 is a schematic of exemplary biochemical pathways leading to glutarate methyl ester or glutaryl-CoA from malonyl-CoA using NADPH as reducing equivalent.

    [0085] FIG. 3 is a schematic of exemplary biochemical pathways leading to glutarate methyl ester or glutaryl-CoA from malonyl-CoA using NADH as reducing equivalent.

    [0086] FIG. 4 is a schematic of exemplary biochemical pathways leading to glutarate using glutarate methyl ester, glutaryl-[acp] or glutaryl-CoA as central precursor.

    [0087] FIG. 5 is a schematic of an exemplary biochemical pathway leading to 5-hydroxypentanoate using glutarate methyl ester or glutarate as a central precursor.

    [0088] FIG. 6 is a schematic of an exemplary biochemical pathway leading to 2,4-pentadienoyl-CoA using 5-hydroxypentanoate as a central precursor.

    [0089] FIG. 7 is a schematic of an exemplary biochemical pathway leading to 1,3-butadiene using 2,4-pentadienoyl-CoA as central precursor.

    [0090] FIG. 8 contains the amino acid sequences of an Escherichia coli pimeloyl-[acp] methyl ester methylesterase (see Genbank Accession No. AAC76437.1, SEQ ID NO: 1), a Mycobacterium marinum carboxylate reductase (see Genbank Accession No. ACC40567.1, SEQ ID NO: 2), a Mycobacterium smegmatis carboxylate reductase (see Genbank Accession No. ABK71854.1, SEQ ID NO: 3), a Segniliparus rugosus carboxylate reductase (see Genbank Accession No. EFV11917.1, SEQ ID NO: 4), a Mycobacterium smegmatis carboxylate reductase (see Genbank Accession No. ABK75684.1, SEQ ID NO: 5), a Mycobacterium massiliense carboxylate reductase (see Genbank Accession No. EIV11143.1, SEQ ID NO: 6), a Segniliparus rotundus carboxylate reductase (see Genbank Accession No. ADG98140.1, SEQ ID NO: 7), an Pseudomonas fluorescens esterase (see Genbank Accession No. AAC60471.2, SEQ ID NO: 8), a Lactobacillus brevis acyl-[acp] thioesterase (see Genbank Accession NO: ABJ63754.1, SEQ ID NO:9), a Lactobacillus plantarum acyl-[acp] thioesterase (see Genbank Accession Nos. CCC78182.1, SEQ ID NO: 10), a Treponema denticola enoyl-CoA reductase (see, e.g., Genbank Accession No. AAS11092.1, SEQ ID NO: 11), an Euglena gracilis enoyl-CoA reductase (see, e.g., Genbank Accession No. AAW66853.1, SEQ ID NO: 12), a Bacillus cereus malonyl-[acp] O-methyltransferase (see, e.g., Genbank Accession No. AAP11034.1, SEQ ID NO: 13), an Escherichia coli thioesterase (see, e.g., Genbank Accession No. AAB59067.1, SEQ ID NO: 14), and an Escherichia coli thioesterase (see, e.g., Genbank Accession No. AAA24665.1, SEQ ID NO: 15), a Bacillus subtilis phosphopantetheinyl transferase (see Genbank Accession No. CAA44858.1, SEQ ID NO:16), a Nocardia sp. NRRL 5646 phosphopantetheinyl transferase (see Genbank Accession No. ABI83656.1, SEQ ID NO:17),

    [0091] FIG. 9 is a bar graph summarizing the change in absorbance at 340 nm after 20 minutes, which is a measure of the consumption of NADPH and activity of five carboxylate reductase preparations in enzyme only controls (no substrate).

    [0092] FIG. 10 is a bar graph of the change in absorbance at 340 nm after 20 minutes, which is a measure of the consumption of NADPH and activity of a carboxylate reductase preparation for converting glutarate methyl ester to glutarate semialdehyde methyl ester relative to the empty vector control.

    [0093] FIG. 11 is a table of conversion after 1 hour of glutaryl-CoA methyl ester to glutaryl-CoA by pimeloyl-[acp] methyl ester methylesterase.

    DETAILED DESCRIPTION

    [0094] This document provides enzymes, non-natural pathways, cultivation strategies, feedstocks, host microorganisms and attenuations to the host's biochemical network, which can be used to synthesize 2,4-pentadienoyl-CoA and, optionally, 1,3-butadiene (also known as buta-1,3 -diene, biethylene, or vinylethylene) from central precursors or central metabolites. Production of butadiene thus can proceed through a common intermediate, 2,4-pentadienoyl-CoA, even though there are a number of different feedstocks and different pathways that can be used to produce 2,4-pentadienoyl-CoA. For example, malonyl-CoA or malonyl-[acp] can be used to produce 2,4-pentadienoyl-CoA via different methyl-ester shielded routes. As used herein, the term central precursor is used to denote any metabolite in any metabolic pathway shown herein leading to the synthesis of 5-hydroxypentanoate, 2,4-pentadienoyl-CoA or butadiene. The term central metabolite is used herein to denote a metabolite that is produced in all microorganisms to support growth.

    [0095] As such, host microorganisms described herein can include endogenous pathways that can be manipulated such that 2,4-pentadienoyl-CoA can be produced. In an endogenous pathway, the host microorganism naturally expresses all of the enzymes catalyzing the reactions within the pathway. A host microorganism containing an engineered pathway does not naturally express all of the enzymes catalyzing the reactions within the pathway but has been engineered such that all of the enzymes within the pathway are expressed in the host.

    [0096] The term exogenous as used herein with reference to a nucleic acid (or a protein) and a host refers to a nucleic acid that does not occur in (and cannot be obtained from) a cell of that particular type as it is found in nature or a protein encoded by such a nucleic acid. Thus, a non-naturally-occurring nucleic acid is considered to be exogenous to a host once in the host. It is important to note that non-naturally-occurring nucleic acids can contain nucleic acid subsequences or fragments of nucleic acid sequences that are found in nature provided the nucleic acid as a whole does not exist in nature. For example, a nucleic acid molecule containing a genomic DNA sequence within an expression vector is non-naturally-occurring nucleic acid, and thus is exogenous to a host cell once introduced into the host, since that nucleic acid molecule as a whole (genomic DNA plus vector DNA) does not exist in nature. Thus, any vector, autonomously replicating plasmid, or virus (e.g., retrovirus, adenovirus, or herpes virus) that as a whole does not exist in nature is considered to be non-naturally-occurring nucleic acid. It follows that genomic DNA fragments produced by PCR or restriction endonuclease treatment as well as cDNAs are considered to be non-naturally-occurring nucleic acid since they exist as separate molecules not found in nature. It also follows that any nucleic acid containing a promoter sequence and polypeptide-encoding sequence (e.g., cDNA or genomic DNA) in an arrangement not found in nature is non-naturally-occurring nucleic acid. A nucleic acid that is naturally-occurring can be exogenous to a particular host microorganism. For example, an entire chromosome isolated from a cell of yeast x is an exogenous nucleic acid with respect to a cell of yeast y once that chromosome is introduced into a cell of yeast y.

    [0097] In contrast, the term endogenous as used herein with reference to a nucleic acid (e.g., a gene) (or a protein) and a host refers to a nucleic acid (or protein) that does occur in (and can be obtained from) that particular host as it is found in nature. Moreover, a cell endogenously expressing a nucleic acid (or protein) expresses that nucleic acid (or protein) as does a host of the same particular type as it is found in nature. Moreover, a host endogenously producing or that endogenously produces a nucleic acid, protein, or other compound produces that nucleic acid, protein, or compound as does a host of the same particular type as it is found in nature.

    [0098] For example, depending on the host and the compounds produced by the host, one or more of the following enzymes may be expressed in the host including a malonyl-[acp] O-methyltransferase, a pimeloyl-[acp] methyl ester methylesterase, an esterase, a reversible CoA-ligase, CoA-transferase, a 4-hydroxybutyrate dehydrogenase, a 5-hydroxypentanoate dehydrogenase, a 6-hydroxyhexanoate dehydrogenase, an alcohol dehydrogenase, a 5-oxopentanoate dehydrogenase, a 6-oxohexanoate dehydrogenase, a 7-oxoheptanoate dehydrogenase, an aldehyde dehydrogenase, or a carboxylate reductase. In recombinant hosts expressing a carboxylate reductase, a phosphopantetheinyl transferase also can be expressed as it enhances activity of the carboxylate reductase.

    [0099] This document also features a recombinant host that includes at least one exogenous nucleic acid encoding (i) a polypeptide having malonyl-[acp] O-methyltransferase activity, (ii) a polypeptide having pimeloyl-[acp] methyl ester methylesterase activity and (iii) a polypeptide having thioesterase activity, and produce glutarate methyl ester, glutaryl-[acp] or glutaryl-CoA.

    [0100] Such a recombinant host producing glutarate methyl ester further can include a polypeptide having esterase activity, and further produce glutaric acid.

    [0101] Such a recombinant host producing glutaryl-[acp] further can include a polypeptide having thioesterase activity and produce glutaric acid.

    [0102] Such a recombinant host producing glutaryl-CoA further can include one or more of (i) a polypeptide having thioesterase activity, (ii) a polypeptide having reversible CoA-ligase activity, (iii) a polypeptide having CoA-transferase activity, or (iv) a polypeptide having acylating dehydrogenase activity, and (v) a polypeptide having aldehyde dehydrogenase activity such as a 7-oxoheptanoate dehydrogenase, 6-oxohexanoate dehydrogenase or 5-oxopentanoate dehydrogenase activity and further produce glutaric acid or 5-oxopentanoate.

    [0103] A recombinant host producing 5-oxopentanoate or glutaric acid further can include one or more of (i) a polypeptide having alcohol dehydrogenase activity or (ii) a polypeptide having carboxylate reductase activity and further produce 5-hydroxypentanoate.

    [0104] A recombinant host producing glutarate methyl ester further can include one or more of (i) a polypeptide having alcohol dehydrogenase activity, (ii) a polypeptide having esterase activity or (iii) a polypeptide having carboxylate reductase activity and further produce 5-hydroxypentanoate.

    [0105] Within an engineered pathway, the enzymes can be from a single source, i.e., from one species or genus, or can be from multiple sources, i.e., different species or genera. Nucleic acids encoding the enzymes described herein have been identified from various organisms and are readily available in publicly available databases such as GenBank or EMBL.

    [0106] Any of the enzymes described herein that can be used for production of one or more C5 building blocks can have at least 70% sequence identity (homology) (e.g., at least 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) to the amino acid sequence of the corresponding wild-type enzyme. It will be appreciated that the sequence identity can be determined on the basis of the mature enzyme (e.g., with any signal sequence removed) or on the basis of the immature enzyme (e.g., with any signal sequence included). It also will be appreciated that the initial methionine residue may or may not be present on any of the enzyme sequences described herein.

    [0107] For example, a polypeptide having pimeloyl-[acp] methyl ester methylesterase activity described herein can have at least 70% sequence identity (homology) (e.g., at least 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) to the amino acid sequence of an Escherichia coli (see Genbank Accession Nos. AAC76437.1, SEQ ID NO: 1)pimeloyl-[acp] methyl ester methylesterase. See FIG. 1-3.

    [0108] For example, a polypeptide having carboxylate reductase activity described herein can have at least 70% sequence identity (homology) (e.g., at least 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) to the amino acid sequence of a Mycobacterium marinum (see Genbank Accession No. ACC40567.1, SEQ ID NO: 2), a Mycobacterium smegmatis (see Genbank Accession No. ABK71854.1, SEQ ID NO: 3), a Segniliparus rugosus (see Genbank Accession No. EFV11917.1, SEQ ID NO: 4), a Mycobacterium smegmatis (see Genbank Accession No. ABK75684.1, SEQ ID NO: 5), a Mycobacterium massiliense (see Genbank Accession No. EIV11143.1, SEQ ID NO: 6), or a Segniliparus rotundus (see Genbank Accession No. ADG98140.1, SEQ ID NO: 7) carboxylate reductase. See, FIG. 5.

    [0109] For example, a polypeptide having phosphopantetheinyl transferase activity described herein can have at least 70% sequence identity (homology) (e.g., at least 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) to the amino acid sequence of a Bacillus subtilis phosphopantetheinyl transferase (see Genbank Accession No. CAA44858.1, SEQ ID NO: 16) or a Nocardia sp. NRRL 5646 phosphopantetheinyl transferase (see Genbank Accession No. ABI83656.1, SEQ ID NO: 17). See FIG. 5.

    [0110] For example, a polypeptide having esterase activity described herein can have at least 70% sequence identity (homology) (e.g., at least 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) to the amino acid sequence of a Pseudomonas fluorescens esterase (see Genbank Accession Nos. AAC60471.2, SEQ ID NO: 8). See FIG. 4, 5.

    [0111] For example, a polypeptide having thioesterase activity described herein can have at least 70% sequence identity (homology) (e.g., at least 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) to the amino acid sequence of a Lactobacillus brevis acyl-[acp] thioesterase (see Genbank Accession Nos. ABJ63754.1, SEQ ID NO: 9), a Lactobacillus plantarum acyl-[acp] thioesterase (see Genbank Accession Nos. CCC78182.1, SEQ ID NO: 10), or a Escherichia coli thioesterase (see Genbank Accession Nos. AAB59067.1 or AAA24665.1, SEQ ID NO: 14 or 15). See FIG. 4.

    [0112] For example, a polypeptide having malonyl-[acp] O-methyltransferase activity described herein can have at least 70% sequence identity (homology) (e.g., at least 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) to the amino acid sequence of a Bacillus cereus (see Genbank Accession Nos. AAP11034.1, SEQ ID NO: 13) malonyl-[acp] O-methyltransferase. See FIG. 1-3.

    [0113] For example, a polypeptide having enoyl-CoA reductase activity described herein can have at least 70% sequence identity (homology) (e.g., at least 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%) to the amino acid sequence of a Treponema denticola (see Genbank Accession Nos. AAS11092.1, SEQ ID NO:11), or a Euglena gracilis (see Genbank Accession Nos. AAW66853.1, SEQ ID NO:12) enoyl-CoA reductase. See FIGS. 1-3.

    [0114] The percent identity (homology) between two amino acid sequences can be determined as follows. First, the amino acid sequences are aligned using the BLAST 2 Sequences (B12seq) program from the stand-alone version of BLASTZ containing BLASTP version 2.0.14. This stand-alone version of BLASTZ can be obtained from Fish & Richardson's web site (e.g., www.fr.com/blast/) or the U.S. government's National Center for Biotechnology Information web site (www.ncbi.nlm.nih.gov). Instructions explaining how to use the B12seq program can be found in the readme file accompanying BLASTZ. B12seq performs a comparison between two amino acid sequences using the BLASTP algorithm. To compare two amino acid sequences, the options of B12seq are set as follows: -i is set to a file containing the first amino acid sequence to be compared (e.g., C:\seq1.txt); -j is set to a file containing the second amino acid sequence to be compared (e.g., C:\seq2.txt); -p is set to blastp; -o is set to any desired file name (e.g., C:\output.txt); and all other options are left at their default setting. For example, the following command can be used to generate an output file containing a comparison between two amino acid sequences: C:\B12seq -i c:\seq1.txt -j c:\seq2.txt -p blastp -o c:\output.txt. If the two compared sequences share homology (identity), then the designated output file will present those regions of homology as aligned sequences. If the two compared sequences do not share homology (identity), then the designated output file will not present aligned sequences. Similar procedures can be following for nucleic acid sequences except that blastn is used.

    [0115] Once aligned, the number of matches is determined by counting the number of positions where an identical amino acid residue is presented in both sequences. The percent identity (homology) is determined by dividing the number of matches by the length of the full-length polypeptide amino acid sequence followed by multiplying the resulting value by 100. It is noted that the percent identity (homology) value is rounded to the nearest tenth. For example, 78.11, 78.12, 78.13, and 78.14 is rounded down to 78.1, while 78.15, 78.16, 78.17, 78.18, and 78.19 is rounded up to 78.2. It also is noted that the length value will always be an integer.

    [0116] It will be appreciated that a number of nucleic acids can encode a polypeptide having a particular amino acid sequence. The degeneracy of the genetic code is well known to the art; i.e., for many amino acids, there is more than one nucleotide triplet that serves as the codon for the amino acid. For example, codons in the coding sequence for a given enzyme can be modified such that optimal expression in a particular species (e.g., bacteria or fungus) is obtained, using appropriate codon bias tables for that species.

    [0117] Functional fragments of any of the enzymes described herein can also be used in the methods of the document. The term functional fragment as used herein refers to a peptide fragment of a protein that has at least 25% (e.g., at least: 30%; 40%; 50%; 60%; 70%; 75%; 80%; 85%; 90%; 95%; 98%; 99%; 100%; or even greater than 100%) of the activity of the corresponding mature, full-length, wild-type protein. The functional fragment can generally, but not always, be comprised of a continuous region of the protein, wherein the region has functional activity.

    [0118] This document also provides (i) functional variants of the enzymes used in the methods of the document and (ii) functional variants of the functional fragments described above. Functional variants of the enzymes and functional fragments can contain additions, deletions, or substitutions relative to the corresponding wild-type sequences. Enzymes with substitutions will generally have not more than 50 (e.g., not more than one, two, three, four, five, six, seven, eight, nine, ten, 12, 15, 20, 25, 30, 35, 40, or 50) amino acid substitutions (e.g., conservative substitutions). This applies to any of the enzymes described herein and functional fragments. A conservative substitution is a substitution of one amino acid for another with similar characteristics. Conservative substitutions include substitutions within the following groups: valine, alanine and glycine; leucine, valine, and isoleucine; aspartic acid and glutamic acid; asparagine and glutamine; serine, cysteine, and threonine; lysine and arginine; and phenylalanine and tyrosine. The nonpolar hydrophobic amino acids include alanine, leucine, isoleucine, valine, proline, phenylalanine, tryptophan and methionine. The polar neutral amino acids include glycine, serine, threonine, cysteine, tyrosine, asparagine and glutamine. The positively charged (basic) amino acids include arginine, lysine and histidine. The negatively charged (acidic) amino acids include aspartic acid and glutamic acid. Any substitution of one member of the above-mentioned polar, basic or acidic groups by another member of the same group can be deemed a conservative substitution. By contrast, a nonconservative substitution is a substitution of one amino acid for another with dissimilar characteristics.

    [0119] Deletion variants can lack one, two, three, four, five, six, seven, eight, nine, ten, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 amino acid segments (of two or more amino acids) or non-contiguous single amino acids. Additions (addition variants) include fusion proteins containing: (a) any of the enzymes described herein or a fragment thereof; and (b) internal or terminal (C or N) irrelevant or heterologous amino acid sequences. In the context of such fusion proteins, the term heterologous amino acid sequences refers to an amino acid sequence other than (a). A heterologous sequence can be, for example a sequence used for purification of the recombinant protein (e.g., FLAG, polyhistidine (e.g., hexahistidine), hemagglutinin (HA), glutathione-S-transferase (GST), or maltosebinding protein (MBP)). Heterologous sequences also can be proteins useful as detectable markers, for example, luciferase, green fluorescent protein (GFP), or chloramphenicol acetyl transferase (CAT). In some embodiments, the fusion protein contains a signal sequence from another protein. In certain host cells (e.g., yeast host cells), expression and/or secretion of the target protein can be increased through use of a heterologous signal sequence. In some embodiments, the fusion protein can contain a carrier (e.g., KLH) useful, e.g., in eliciting an immune response for antibody generation) or ER or Golgi apparatus retention signals. Heterologous sequences can be of varying length and in some cases can be a longer sequences than the full-length target proteins to which the heterologous sequences are attached.

    [0120] Engineered hosts can naturally express none or some (e.g., one or more, two or more, three or more, four or more, five or more, or six or more) of the enzymes of the pathways described herein. Thus, a pathway within an engineered host can include all exogenous enzymes, or can include both endogenous and exogenous enzymes. Endogenous genes of the engineered hosts also can be disrupted to prevent the formation of undesirable metabolites or prevent the loss of intermediates in the pathway through other enzymes acting on such intermediates. Engineered hosts can be referred to as recombinant hosts or recombinant host cells. As described herein recombinant hosts can include nucleic acids encoding one or more polypeptide having the activity of a reductase, deacetylase, N-acetyltransferase, malonyl-[acp] O-methyltransferase, esterase, thioesterase, hydratase, dehydrogenase, CoA-ligase, and/or CoA-transferase as described herein.

    [0121] In addition, the production of one or more C5 building blocks can be performed in vitro using the isolated enzymes described herein, using a lysate (e.g., a cell lysate) from a host microorganism as a source of the enzymes, or using a plurality of lysates from different host microorganisms as the source of the enzymes.

    Enzymes Generating the Terminal Carboxyl Groups in the Biosynthesis of 2,4-Pentadienoyl-CoA

    [0122] As depicted in FIG. 4, a terminal carboxyl group can be enzymatically formed using (i) a polypeptide having thioesterase activity, (ii) a polypeptide having reversible CoA-ligase activity, (iii) a polypeptide having CoA-transferase activity, (iv) a polypeptide having acylating dehydrogenase activity, or (v) a polypeptide having aldehyde dehydrogenase activity such as a 7-oxoheptanoate dehydrogenase, a 6-oxohexanoate dehydrogenase, or a 5-oxopentanoate dehydrogenase activity, or (vi) a polypeptide having esterase activity.

    [0123] In some embodiments, a terminal carboxyl group leading to the synthesis of glutarate is enzymatically formed by a thioesterase classified under EC 3.1.2., such as the gene product of YciA (SEQ ID NO: 14), tesB (Genbank Accession No. AAA24665.1, SEQ ID NO: 15) or Acot13 (see, for example, Cantu et al., Protein Science, 2010, 19, 1281-1295; Zhuang et al., Biochemistry, 2008, 47(9), 2789-2796; or Naggert et al., J. Biol. Chem., 1991, 266(17), 11044-11050).

    [0124] In some embodiments, the second terminal carboxyl group leading to the synthesis of glutaric acid is enzymatically formed by a CoA-transferase such as a glutaconate CoA-transferase classified, for example, under EC 2.8.3.12 such as from Acidaminococcus fermentans. See, for example, Buckel et al., 1981, Eur. J. Biochem., 118:315-321. FIG. 4.

    [0125] In some embodiments, the second terminal carboxyl group leading to the synthesis of glutaric acid is enzymatically formed by a reversible CoA-ligase such as a succinate-CoA ligase classified, for example, under EC 6.2.1.5 such as from Thermococcus kodakaraensis. See, for example, Shikata et al., 2007, J. Biol. Chem., 282(37):26963-26970.

    [0126] In some embodiments, the second terminal carboxyl group leading to the synthesis of glutaric acid is enzymatically formed by an acyl-[acp] thioesterase classified under EC 3.1.2., such as the acyl-[acp] thioesterase from Lactobacillus brevis (GenBank Accession No. ABJ63754.1, SEQ ID NO: 9) or from Lactobacillus plantarum (GenBank Accession No. CCC78182.1, SEQ ID NO: 10). Such acyl-[acp] thioesterases have C6-C8 chain length specificity (see, for example, Jing et al., 2011, BMC Biochemistry, 12(44)). See, e.g., FIG. 4.

    [0127] In some embodiments, the second terminal carboxyl group leading to the synthesis of glutaric acid is enzymatically formed by an aldehyde dehydrogenase classified, for example, under EC 1.2.1.3 (see, Guerrillot & Vandecasteele, Eur. J. Biochem., 1977, 81, 185-192). See, FIG. 4.

    [0128] In some embodiments, the second terminal carboxyl group leading to the synthesis of glutaric acid is enzymatically formed by an aldehyde dehydrogenase classified under EC 1.2.1.such as a glutarate semialdehyde dehydrogenase classified, for example, under EC 1.2.1.20, a succinate-semialdehyde dehydrogenase classified, for example, under EC 1.2.1.16 or EC 1.2.1.79, or an aldehyde dehydrogenase classified under EC 1.2.1.3. For example, an aldehyde dehydrogenase classified under EC 1.2.1.can be a 5-oxopentanoate dehydrogenase such as the gene product of CpnE, a 6-oxohexanoate dehydrogenase (e.g., the gene product of ChnE from Acinetobacter sp.), or a 7-oxoheptanoate dehydrogenase (e.g., the gene product of ThnG from Sphingomonas macrogolitabida) (Iwaki et al., Appl. Environ. Microbiol., 1999, 65(11), 5158-5162; Lopez-Sanchez et al., Appl. Environ. Microbiol., 2010, 76(1), 110-118). For example, a 6-oxohexanoate dehydrogenase can be classified under EC 1.2.1.63 such as the gene product of ChnE. For example, a 7-oxoheptanoate dehydrogenase can be classified under EC 1.2.1.-.

    [0129] In some embodiments, the second terminal carboxyl group leading to the synthesis of glutaric acid is enzymatically formed by a polypeptide having esterase activity such as an esterase classified under EC 3.1.1.such as EC 3.1.1.1 or EC 3.1.1.6.

    [0130] Enzymes Generating the Terminal Hydroxyl Groups in the Biosynthesis of a 2,4-Pentadienoyl-CoA

    [0131] As depicted in FIGS. 5, a terminal hydroxyl group can be enzymatically formed using an alcohol dehydrogenase such as a 6-hydroxyhexanoate dehydrogenase, a 5-hydroxypentanoate dehydrogenase, or a 4-hydroxybutyrate dehydrogenase.

    [0132] For example, a terminal hydroxyl group leading to the synthesis of 5-hydroxypentanoate can be enzymatically formed by a dehydrogenase classified, for example, under EC 1.1.1.such as a 6-hydroxyhexanoate dehydrogenase classified, for example, under EC 1.1.1.258 (e.g., the gene from of ChnD), a 5-hydroxypentanoate dehydrogenase classified, for example, under EC 1.1.1.such as the gene product of CpnD (see, for example, Iwaki et al., 2002, Appl. Environ. Microbiol., 68(11):5671-5684), a 5-hydroxypentanoate dehydrogenase from Clostridium viride, or a 4-hydroxybutyrate dehydrogenase such as gabD (see, for example, Ltke-Eversloh & Steinbtichel, 1999, FEMS Microbiology Letters, 181(1):63-71). See, FIG. 5.

    Enzymes Generating the Terminal Vinyl Group in the Biosynthesis of a 2,4-Pentadienoyl-CoA

    [0133] As depicted in FIGS. 6, a terminal vinyl group can be enzymatically formed using a dehydratase such as 5-hydroxypentanoyl-CoA dehydratase from Clostridium viride (Eikmanns and Buckel, 1991, Eur. J. Biochem., 197, 661-668).

    Biochemical Pathways

    [0134] Pathway to Glutarate Methyl Ester, Glutaryl-CoA or Glutaryl-[acp] from Malonyl-[acp] or Malonyl-CoA

    [0135] As shown in FIG. 1, glutarate methyl ester can be synthesized from malonyl-[acp] by conversion of malonyl-[acp] to malonyl-[acp] methyl ester by a malonyl-CoA O-methyltransferase classified, for example, under EC 2.1.1.197 such as the gene product of bioC; followed by conversion to 3-oxoglutaryl-[acp] methyl ester by condensation with malonyl-[acp] and a -ketoacyl-[acp] synthase classified, for example, under EC 2.3.1.such as EC 2.3.1.41, EC 2.3.1.179 or EC 2.3.1.180 (e.g., the gene product of fabB, fabF or fabH); followed by conversion to 3-hydroxy-glutaryl-[acp] methyl ester by a 3-hydroxyacyl-CoA dehydrogenase classified, for example, under EC 1.1.1.such as EC 1.1.1.100 (e.g., the gene product of fabG); followed by conversion to 2,3-dehydroglutaryl-[acp] methyl ester by a 3-hydroxyacyl-[acp] dehydratase classified, for example, under EC 4.2.1.59 such as the gene product of fabZ; followed by conversion to glutaryl-[acp] methyl ester by a trans-2-enoyl-CoA reductase classified, for example, EC 1.3.1.such as EC 1.3.1.10 such as the gene product of fabI; followed by (i) conversion to glutarate methyl ester by a thioesterase classified, for example, under EC 3.1.2.such as the tesB (SEQ ID NO:15), YciA (SEQ ID NO:14) or Acot13, a Bacteroides thetaiotaomicron acyl-ACP thioesterase (GenBank Accession No. AAO77182) or a Lactobacillus plantarum acyl-CoA thioesterase (GenBank Accession No. CCC78182.1) or (ii) conversion to glutaryl-[acp] by a pimeloyl-[acp] methyl ester methylesterase classified, for example, under EC 3.1.1.85 such as bioH(SEQ ID NO: 1).

    [0136] As shown in FIG. 2, glutarate methyl ester can be synthesized from malonyl-CoA by conversion of malonyl-CoA to malonyl-CoA methyl ester by a malonyl-CoA O-methyltransferase classified, for example, under EC 2.1.1.197 such as the gene product of bioC; followed by conversion to 3-oxoglutaryl-CoA methyl ester by condensation with acetyl-CoA by a -ketothiolase classified, for example, under EC 2.3.1.16 such as the gene product of bktB or by condensation with malonyl-CoA by a -ketoacyl-[acp] synthase classified, for example, under EC 2.3.1.180 such as the gene product of fabH; followed by conversion to 3-hydroxy-glutaryl-CoA methyl ester by a 3-hydroxyacyl-CoA dehydrogenase classified, for example, under EC 1.1.1.such as EC 1.1.1.100 (e.g., the gene product of fabG) or EC 1.1.1.36 (e.g., the gene product of phaB); followed by conversion to 2,3-dehydroglutaryl-CoA methyl ester by an enoyl-CoA hydratase classified, for example, under EC 4.2.1.119 such as the gene product of phaJ (Shen et al., Appl. Environ. Microbiol., 2011, 77(9), 2905-2915; Fukui et al., Journal of Bacteriology, 1998, 180(3), 667-673); followed by conversion to glutaryl-CoA methyl ester by a trans-2-enoyl-CoA reductase classified, for example, EC 1.3.1.such as EC 1.3.1.38, EC 1.3.1.8, EC 1.3.1.10 or EC 1.3.1.44; followed by (i) conversion to glutarate methyl ester by a thioesterase classified, for example, under EC 3.1.2.such as the tesB (SEQ ID NO:15), YciA (SEQ ID NO:14) or Acot13, a Bacteroides thetaiotaomicron acyl-ACP thioesterase (GenBank Accession No. AAO77182) or a Lactobacillus plantarum acyl-ACP thioesterase (GenBank Accession No. CCC78182.1) or (ii) conversion to glutaryl-CoA by a pimeloyl-[acp] methyl ester methylesterase classified, for example, under EC 3.1.1.85 such as bioH (SEQ ID NO: 1).

    [0137] As shown in FIG. 3, glutarate methyl ester can be synthesized from malonyl-CoA by conversion of malonyl-CoA to malonyl-CoA methyl ester by a malonyl-CoA O-methyltransferase classified, for example, under EC 2.1.1.197 such as the gene product of bioC; followed by conversion to 3-oxoglutaryl-CoA methyl ester by condensation with acetyl-CoA by a -ketothiolase classified, for example, under EC 2.3.1.16 such as the gene product of bktB or by condensation with malonyl-CoA by a -ketoacyl-[acp] synthase classified, for example, under EC 2.3.1.180 such as the gene product of fabH; followed by conversion to 3-hydroxy-glutaryl-CoA methyl ester by a 3-hydroxyacyl-CoA dehydrogenase classified, for example, under EC 1.1.1.such as EC 1.1.1.35 or EC 1.1.1.157 (e.g., the gene product of fadB or hbd); followed by conversion to 2,3-dehydroglutaryl-CoA methyl ester by an enoyl-CoA hydratase classified, for example, under EC 4.2.1.17 such as the gene product of crt; followed by conversion to glutaryl-CoA methyl ester by a trans-2-enoyl-CoA reductase classified, for example, under EC 1.3.1.44 such as the gene product of ter or tdter; followed by (i) conversion to glutarate methyl ester by a thioesterase classified, for example, under EC 3.1.2.such as the tesB (SEQ ID NO:15), YciA (SEQ ID NO:14) or Acot13, a Bacteroides thetaiotaomicron acyl-ACP thioesterase (GenBank Accession No. AAO77182) or a Lactobacillus plantarum acyl-CoA thioesterase (GenBank Accession No. CCC78182.1) or (ii) conversion to glutaryl-CoA by a pimeloyl-[acp] methyl ester methylesterase classified, for example, under EC 3.1.1.85 such as bioH (SEQ ID NO: 1).

    Pathway to Glutarate or 5-Oxopentanoate Using Glutarate Methyl Ester, Glutaryl-[acp] or Glutaryl-CoA as a Central Precursor

    [0138] As depicted in FIG. 4, glutarate methyl ester can be converted to glutarate by an esterase classified, for example, EC 3.1.1., such as EC 3.1.1.1 or EC 3.1.1.6 such as estC (SEQ ID NO: 8).

    [0139] As depicted in FIG. 4, glutaryl-CoA can be converted to glutarate by a (i) a thioesterase classified, for example, EC 3.1.2., such as the tesB (SEQ ID NO:15), YciA (SEQ ID NO:14) or Acot13, a Bacteroides thetaiotaomicron acyl-ACP thioesterase (GenBank Accession No. AAO77182) or a Lactobacillus plantarum acyl-CoA thioesterase (GenBank Accession No. CCC78182.1) (ii) a reversible CoA-ligase classified, for example, under EC 6.2.1.5, (iii) a CoA-transferase classified, for example, under EC 2.8.3.such as EC 2.8.3.12, or (iv) an acylating dehydrogenase classified under, for example, EC 1.2.1.10 or EC 1.2.1.76 such as encoded by PduB or PduP and an aldehyde dehydrogenase classified under EC 1.2.1.such as a glutarate semialdehyde dehydrogenase classified, for example, under EC 1.2.1.20, a succinate-semialdehyde dehydrogenase classified, for example, under EC 1.2.1.16 or EC 1.2.1.79, or an aldehyde dehydrogenase classified under EC 1.2.1.3. For example, a 5-oxovalerate dehydrogenase such as the gene product of CpnE, a 6-oxohexanoate dehydrogenase such as the gene product of ChnE, or a 7-oxoheptanoate dehydrogenase (e.g., the gene product of ThnG from Sphingomonas macrogolitabida) can be used to convert 5-oxopentanoic acid to glutarate.

    [0140] As depicted in FIG. 4, glutaryl-[acp] can be converted to glutarate by a thioesterase classified, for example, EC 3.1.2.-, such as the tesB (SEQ ID NO:15), YciA (SEQ ID NO:14) or Acot13, a Bacteroides thetaiotaomicron acyl-ACP thioesterase (GenBank Accession No. AAO77182) or a Lactobacillus plantarum acyl-CoA thioesterase (GenBank Accession No. CCC78182.1).

    Pathway to 5-Hydroxypentanoate Using Glutarate Methyl ester as a Central Precursor

    [0141] As depicted in FIG. 5, 5-hydroxypentanoate can be synthesized from the central precursor glutarate methyl ester by conversion of glutarate methyl ester to glutaric acid by an esterase classified under EC 3.1.1.(e.g., the gene product of estC) such as a carboxyl esterase classified under EC 3.1.1.1 or an acetylesterase classified under EC 3.1.1.6; followed by conversion of glutaric acid to glutarate semialdehyde by a carboxylate reductase classified, for example, under EC 1.2.99.6 such as the gene product of car in combination with a phosphopantetheine transferase enhancer (e.g., encoded by a sfp (Genbank Accession No. CAA44858.1, SEQ ID NO:16) gene from Bacillus subtilis or npt (Genbank Accession No. ABI83656.1, SEQ ID NO:17) gene from Nocardia), or the gene product of GriC & GriD (Suzuki et al., J. Antibiot., 2007, 60(6), 380-387); followed by conversion to 5-hydroxypentanoate by a dehydrogenase classified, for example, under EC 1.1.1.such as a 6-hydroxyhexanoate dehydrogenase classified, for example, under EC 1.1.1.258 (e.g., the gene from of ChnD), a 5-hydroxypentanoate dehydrogenase classified, for example, under EC 1.1.1.such as the gene product of CpnD (see, for example, Iwaki et al., 2002, Appl. Environ. Microbiol., 68(11):5671-5684), or a 4-hydroxybutyrate dehydrogenase such as gabD (see, for example, Lke-Eversloh & Steinbtichel, 1999, FEMS Microbiology Letters, 181(1):63-71). See, FIG. 5.

    [0142] As depicted in FIG. 5, 5-hydroxypentanoate can be synthesized from the central precursor glutarate methyl ester by conversion of glutarate methyl ester to glutarate semialdehyde methyl ester by a carboxylate reductase classified, for example, under EC 1.2.99.6 such as from a Mycobacterium marinum (see Genbank Accession No. ACC40567.1, SEQ ID NO: 2), a Mycobacterium smegmatis (see Genbank Accession No. ABK71854.1, SEQ ID NO: 3), a Mycobacterium massiliense (see Genbank Accession No. EIV11143.1, SEQ ID NO: 6), or a Segniliparus rotundus (see Genbank Accession No. ADG98140.1, SEQ ID NO: 7), in combination with a phosphopantetheine transferase enhancer (e.g., encoded by a sfp (Genbank Accession No. CAA44858.1, SEQ ID NO:16) gene from Bacillus subtilis or npt (Genbank Accession No. ABI83656.1, SEQ ID NO:17) gene from Nocardia), or the gene product of GriC & GriD (Suzuki et al., J. Antibiot., 2007, 60(6), 380-387); followed by conversion to glutarate semialdehyde by an esterase classified under EC 3.1.1.(e.g., the gene product of estC) such as a carboxyl esterase classified under EC 3.1.1.1 or an acetylesterase classified under EC 3.1.1.6; followed by conversion to 5-hydroxypentanoate by a dehydrogenase classified, for example, under EC 1.1.1.such as a 6-hydroxyhexanoate dehydrogenase classified, for example, under EC 1.1.1.258 (e.g., the gene from of ChnD), a 5-hydroxypentanoate dehydrogenase classified, for example, under EC 1.1.1.such as the gene product of CpnD, or a 4-hydroxybutyrate dehydrogenase such as gabD.

    [0143] As depicted in FIG. 5, 5-hydroxypentanoate can be synthesized from the central precursor glutarate methyl ester by conversion of glutarate methyl ester to glutarate semialdehyde methyl ester by a carboxylate reductase classified, for example, under EC 1.2.99.6 such as from a Mycobacterium marinum (see Genbank Accession No. ACC40567.1, SEQ ID NO: 2), a Mycobacterium smegmatis (see Genbank Accession No. ABK71854.1, SEQ ID NO: 3), a Mycobacterium massiliense (see Genbank Accession No. EIV11143.1, SEQ ID NO: 6), or a Segniliparus rotundus (see Genbank Accession No. ADG98140.1, SEQ ID NO: 7), in combination with a phosphopantetheine transferase enhancer (e.g., encoded by a sfp (Genbank Accession No. CAA44858.1, SEQ ID NO:16) gene from Bacillus subtilis or npt (Genbank Accession No. ABI83656.1, SEQ ID NO:17) gene from Nocardia), or the gene product of GriC & GriD (Suzuki et al., J. Antibiot., 2007, 60(6), 380-387); followed by conversion to 5-hydroxypentanoate methyl ester by an alcohol dehydrogenase classified, for example, under EC 1.1.1.(e.g., EC 1.1.1.1, EC 1.1.1.2, EC 1.1.1.21, or EC 1.1.1.184) such as the gene product of YMR318C, YqhD, or the protein having GenBank Accession No. CAA81612.1; followed by conversion to 5-hydroxypentanoate by an esterase classified under EC 3.1.1.(e.g., the gene product of estC) such as a carboxyl esterase classified under EC 3.1.1.1 or an acetylesterase classified under EC 3.1.1.6.

    Pathway to 2,4-Pentadienoyl-CoA Using 5-Hydroxypentanoate as a Central Precursor

    [0144] As depicted in FIG. 6, 2,4-pentadienoyl-CoA can be synthesized from 5-hydroxypentanoate by conversion of 5-hydroxypentanoate to 5-hydroxypentanoyl-CoA by a 5-hydroxypentanoate CoA-transferase or 4-hydroxybutryrate CoA-transferase classified, for example, under EC 2.8.3.such as EC 2.8.3.14 or EC 2.8.3.9 or by a synthase classified, for example, under EC 6.2.1.such as a 3-hydroxypropionyl-CoA synthase classified under EC 6.2.1.36; followed by conversion to 2,4-pentadienoyl-CoA by a dehydratase such as 5-hydroxypentanoy-CoA dehydratase classified, for example, under EC 4.2.1.obtained from Clostridium viride.

    Cultivation Strategy

    [0145] In some embodiments, the cultivation strategy entails achieving an aerobic, anaerobic, micro-aerobic, or mixed oxygen/denitrification cultivation condition. Enzymes characterized in vitro as being oxygen sensitive require a micro-aerobic cultivation strategy maintaining a very low dissolved oxygen concentration (See, for example, Chayabatra & Lu-Kwang, AppL Environ. Microbiol., 2000, 66(2), 493 0 498; Wilson and Bouwer, 1997, Journal of Industrial Microbiology and Biotechnology, 18(2-3), 116-130).

    [0146] In some embodiments, a cyclical cultivation strategy entails alternating between achieving an anaerobic cultivation condition and achieving an aerobic cultivation condition.

    [0147] In some embodiments, the cultivation strategy entails nutrient limitation such as nitrogen, phosphate or oxygen limitation.

    [0148] In some embodiments, a final electron acceptor other than oxygen such as nitrates can be utilized. In some embodiments, a cell retention strategy using, for example, ceramic membranes can be employed to achieve and maintain a high cell density during either fed-batch or continuous fermentation.

    [0149] In some embodiments, the principal carbon source fed to the fermentation in the synthesis of one or more C5 building blocks can derive from biological or non-biological feedstocks. In some embodiments, the biological feedstock can be or can derive from, monosaccharides, disaccharides, lignocellulose, hemicellulose, cellulose, lignin, levulinic acid and formic acid, triglycerides, glycerol, fatty acids, agricultural waste, condensed distillers' solubles, or municipal waste.

    [0150] The efficient catabolism of crude glycerol stemming from the production of biodiesel has been demonstrated in several microorganisms such as Escherichia coli, Cupriavidus necator, Pseudomonas oleavorans, Pseudomonas putida and Yarrowia lipolytica (Lee et al., AppL Biochem. Biotechnol., 2012, 166:1801-1813; Yang et al., Biotechnology for Biofuels, 2012, 5:13; Meijnen et al., Appl. Microbiol. Biotechnol., 2011, 90:885-893).

    [0151] The efficient catabolism of lignocellulosic-derived levulinic acid has been demonstrated in several organisms such as Cupriavidus necator and Pseudomonas putida in the synthesis of 3-hydroxyvalerate via the precursor propanoyl-CoA (Jaremko and Yu, 2011, supra; Martin and Prather, J. Biotechnol., 2009, 139:61-67).

    [0152] The efficient catabolism of lignin-derived aromatic compounds such as benzoate analogues has been demonstrated in several microorganisms such as Pseudomonas putida, Cupriavidus necator (Bugg et al., Current Opinion in Biotechnology, 2011, 22, 394-400; Prez-Pantoja et al., FEMS Microbiol. Rev., 2008, 32, 736-794).

    [0153] The efficient utilization of agricultural waste, such as olive mill waste water has been demonstrated in several microorganisms, including Yarrowia lipolytica (Papanikolaou et al., Bioresour. Technol., 2008, 99(7):2419-2428).

    [0154] The efficient utilization of fermentable sugars such as monosaccharides and disaccharides derived from cellulosic, hemicellulosic, cane and beet molasses, cassava, corn and other agricultural sources has been demonstrated for several microorganism such as Escherichia coli, Corynebacterium glutamicum and Lactobacillus delbrueckii and Lactococcus lactis (see, e.g., Hermann et al, J. Biotechnol., 2003, 104:155-172; Wee et al., Food Technol. Biotechnol., 2006, 44(2):163-172; Ohashi et al., J. Bioscience and Bioengineering, 1999, 87(5):647-654).

    [0155] The efficient utilization of furfural, derived from a variety of agricultural lignocellulosic sources, has been demonstrated for Cupriavidus necator (Li et al., Biodegradation, 2011, 22:1215-1225).

    [0156] In some embodiments, the non-biological feedstock can be or can derive from natural gas, syngas, CO.sub.2/H.sub.2, methanol, ethanol, benzoate, non-volatile residue (NVR) or a caustic wash waste stream from cyclohexane oxidation processes, or terephthalic acid/isophthalic acid mixture waste streams.

    [0157] The efficient catabolism of methanol has been demonstrated for the methylotrophic yeast Pichia pastoris.

    [0158] The efficient catabolism of ethanol has been demonstrated for Clostridium kluyveri (Seedorf et al., Proc. Natl. Acad. Sci. USA, 2008, 105(6) 2128-2133).

    [0159] The efficient catabolism of CO.sub.2 and H.sub.2, which may be derived from natural gas and other chemical and petrochemical sources, has been demonstrated for Cupriavidus necator (Prybylski et al., Energy, Sustainability and Society, 2012, 2:11).

    [0160] The efficient catabolism of syngas has been demonstrated for numerous microorganisms, such as Clostridium ljungdahlii and Clostridium autoethanogenum (Kpke et al., Applied and Environmental Microbiology, 2011, 77(15):5467-5475).

    [0161] The efficient catabolism of the non-volatile residue waste stream from cyclohexane processes has been demonstrated for numerous microorganisms, such as Delftia acidovorans and Cupriavidus necator (Ramsay et al., Applied and Environmental Microbiology, 1986, 52(1):152-156).

    Metabolic Engineering

    [0162] The present document provides methods involving less than all the steps described for all the above pathways. Such methods can involve, for example, one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve or more of such steps. Where less than all the steps are included in such a method, the first, and in some embodiments the only, step can be any one of the steps listed.

    [0163] Furthermore, recombinant hosts described herein can include any combination of the above enzymes such that one or more of the steps, e.g., one, two, three, four, five, six, seven, eight, nine, ten, or more of such steps, can be performed within a recombinant host. This document provides host cells of any of the genera and species listed and genetically engineered to express one or more (e.g., two, three, four, five, six, seven, eight, nine, 10, 11, 12 or more) recombinant forms of any of the enzymes recited in the document. Thus, for example, the host cells can contain exogenous nucleic acids encoding enzymes catalyzing one or more of the steps of any of the pathways described herein.

    [0164] In addition, this document recognizes that where enzymes have been described as accepting CoA-activated substrates, analogous enzyme activities associated with [acp]-bound substrates exist that are not necessarily in the same enzyme class.

    [0165] Also, this document recognizes that where enzymes have been described accepting (R)-enantiomers of substrate, analogous enzyme activities associated with (S)-enantiomer substrates exist that are not necessarily in the same enzyme class.

    [0166] This document also recognizes that where an enzyme is shown to accept a particular co-factor, such as NADPH, or co-substrate, such as acetyl-CoA, many enzymes are promiscuous in terms of accepting a number of different co-factors or co-substrates in catalyzing a particular enzyme activity. Also, this document recognizes that where enzymes have high specificity for e.g., a particular co-factor such as NADH, an enzyme with similar or identical activity that has high specificity for the co-factor NADPH may be in a different enzyme class.

    [0167] In some embodiments, the enzymes in the pathways outlined herein are the result of enzyme engineering via non-direct or rational enzyme design approaches with aims of improving activity, improving specificity, reducing feedback inhibition, reducing repression, improving enzyme solubility, changing stereo-specificity, or changing co-factor specificity.

    [0168] In some embodiments, the enzymes in the pathways outlined here can be gene dosed, i.e., overexpressed, into the resulting genetically modified organism via episomal or chromosomal integration approaches.

    [0169] In some embodiments, genome-scale system biology techniques such as Flux Balance Analysis can be utilized to devise genome scale attenuation or knockout strategies for directing carbon flux to a 2,4-pentadienoyl-CoA.

    [0170] Attenuation strategies include, but are not limited to; the use of transposons, homologous recombination (double cross-over approach), mutagenesis, enzyme inhibitors and RNAi interference.

    [0171] In some embodiments, fluxomic, metabolomic and transcriptomal data can be utilized to inform or support genome-scale system biology techniques, thereby devising genome scale attenuation or knockout strategies in directing carbon flux to 2,4-pentadienoyl-CoA.

    [0172] In some embodiments, the host microorganism's tolerance to high concentrations of 2,4-pentadienoyl-CoA can be improved through continuous cultivation in a selective environment.

    [0173] In some embodiments, the host microorganism's endogenous biochemical network can be attenuated or augmented to (1) ensure the intracellular availability of acetyl-CoA, (2) create a NADH or NADPH imbalance that may be balanced via the formation of 2,4-pentadienoyl-CoA, and/or (3) prevent degradation of central metabolites, central precursors leading to and including 2,4-pentadienoyl-CoA.

    [0174] In some embodiments requiring intracellular availability of acetyl-CoA-CoA for C5 building block synthesis, endogenous enzymes catalyzing the hydrolysis of acetyl-CoA such as short-chain length thioesterases can be attenuated in the host organism.

    [0175] In some embodiments requiring condensation of acetyl-CoA and malonyl-CoA for 2,4-pentadienoyl-CoA synthesis, one or more endogenous -ketothiolases catalyzing the condensation of only acetyl-CoA to acetoacetyl-CoA such as the endogenous gene products of AtoB or phaA can be attenuated.

    [0176] In some embodiments requiring the intracellular availability of acetyl-CoA for 2,4-pentadienoyl-CoA synthesis, an endogenous phosphotransacetylase generating acetate such as pta can be attenuated (Shen et al., Appl. Environ. Microbiol., 2011, 77(9):2905-2915).

    [0177] In some embodiments requiring the intracellular availability of acetyl-CoA for 2,4-pentadienoyl-CoA synthesis, an endogenous gene in an acetate synthesis pathway encoding an acetate kinase, such as ack, can be attenuated.

    [0178] In some embodiments requiring the intracellular availability of acetyl-CoA and NADH for 2,4-pentadienoyl-CoA synthesis, an endogenous gene encoding an enzyme that catalyzes the degradation of pyruvate to lactate such as a lactate dehydrogenase encoded by ldhA can be attenuated (Shen et al., 2011, supra).

    [0179] In some embodiments requiring the intracellular availability of acetyl-CoA and NADH for 2,4-pentadienoyl-CoA synthesis, endogenous genes encoding enzymes, such as menaquinol-fumarate oxidoreductase, that catalyze the degradation of phophoenolpyruvate to succinate such as frdBC can be attenuated (see, e.g., Shen et al., 2011, supra).

    [0180] In some embodiments requiring the intracellular availability of acetyl-CoA and NADH for 2,4-pentadienoyl-CoAsynthesis, an endogenous gene encoding an enzyme that catalyzes the degradation of acetyl-CoA to ethanol such as the alcohol dehydrogenase encoded by adhE can be attenuated (Shen et al., 2011, supra).

    [0181] In some embodiments, where pathways require excess NADH co-factor for 2,4-pentadienoyl-CoA synthesis, a recombinant formate dehydrogenase gene can be overexpressed in the host organism (Shen et al., 2011, supra).

    [0182] In some embodiments, acetyl-CoA carboxylase can be overexpressed in the host organisms.

    [0183] In some embodiments, one or more of 3-phosphoglycerate dehydrogenase, 3-phosphoserine aminotransferase and phosphoserine phosphatase can be overexpressed in the host to generate serine as a methyl donor for the S-Adenosyl-L-methionine cycle.

    [0184] In some embodiments, a methanol dehydrogenase or a formaldehyde dehydrogenase can be overexpressed in the host to allow methanol catabolism via formate.

    [0185] In some embodiments, where pathways require excess NADH or NADPH co-factor for 2,4-pentadienoyl-CoA synthesis, a transhydrogenase dissipating the cofactor imbalance can be attenuated.

    [0186] In some embodiments, an endogenous gene encoding an enzyme that catalyzes the degradation of pyruvate to ethanol such as pyruvate decarboxylase can be attenuated.

    [0187] In some embodiments, an endogenous gene encoding an enzyme that catalyzes the generation of isobutanol such as a 2-oxoacid decarboxylase can be attenuated.

    [0188] In some embodiments requiring the intracellular availability of acetyl-CoA for 2,4-pentadienoyl-CoA synthesis, a recombinant acetyl-CoA synthetase such as the gene product of acs can be overexpressed in the microorganism (Satoh et al., J. Bioscience and Bioengineering, 2003, 95(4):335-341).

    [0189] In some embodiments, carbon flux can be directed into the pentose phosphate cycle to increase the supply of NADPH by attenuating an endogenous glucose-6-phosphate isomerase (EC 5.3.1.9).

    [0190] In some embodiments, carbon flux can be redirected into the pentose phosphate cycle to increase the supply of NADPH by overexpression a 6-phosphogluconate dehydrogenase and/or a transketolase (Lee et al., 2003, Biotechnology Progress, 19(5), 1444-1449).

    [0191] In some embodiments, where pathways require excess NADPH co-factor in the synthesis of 2,4-pentadienoyl-CoA, a gene such as UdhA encoding apuridine nucleotide transhydrogenase can be overexpressed in the host organisms (Brigham et al., Advanced Biofuels and Bioproducts, 2012, Chapter 39, 1065-1090).

    [0192] In some embodiments, where pathways require excess NADPH co-factor in the synthesis of 2,4-pentadienoyl-CoA, a recombinant glyceraldehyde-3-phosphate-dehydrogenase gene such as GapN can be overexpressed in the host organisms (Brigham et al., 2012, supra).

    [0193] In some embodiments, where pathways require excess NADPH co-factor in the synthesis of 2,4-pentadienoyl-CoA, a recombinant malic enzyme gene such as maeA or maeB can be overexpressed in the host organisms (Brigham et al., 2012, supra).

    [0194] In some embodiments, where pathways require excess NADPH co-factor in the synthesis of 2,4-pentadienoyl-CoA, a recombinant glucose-6-phosphate dehydrogenase gene such as zwf can be overexpressed in the host organisms (Lim et al., J. Bioscience and Bioengineering, 2002, 93(6), 543-549).

    [0195] In some embodiments, where pathways require excess NADPH co-factor in the synthesis of 2,4-pentadienoyl-CoA, a recombinant fructose 1,6 diphosphatase gene such as fbp can be overexpressed in the host organisms (Becker et al., J. Biotechnol., 2007, 132:99-109).

    [0196] In some embodiments, where pathways require excess NADPH co-factor in the synthesis of a C5 building block, endogenous triose phosphate isomerase (EC 5.3.1.1) can be attenuated.

    [0197] In some embodiments, where pathways require excess NADPH co-factor in the synthesis of 2,4-pentadienoyl-CoA, a recombinant glucose dehydrogenase such as the gene product of gdh can be overexpressed in the host organism (Satoh et al., J. Bioscience and Bioengineering, 2003, 95(4):335-341).

    [0198] In some embodiments, endogenous enzymes facilitating the conversion of NADPH to NADH can be attenuated, such as the NADH generation cycle that may be generated via inter-conversion of glutamate dehydrogenases classified under EC 1.4.1.2 (NADH-specific) and EC 1.4.1.4 (NADPH-specific).

    [0199] In some embodiments, an endogenous glutamate dehydrogenase (EC 1.4.1.3) that utilizes both NADH and NADPH as co-factors can be attenuated.

    [0200] In some embodiments, a membrane-bound enoyl-CoA reductase can be solubilized via expression as a fusion protein to a small soluble protein such as a maltose binding protein (Gloerich et al., FEBS Letters, 2006, 580, 2092-2096).

    [0201] In some embodiments using hosts that naturally accumulate polyhydroxyalkanoates, the endogenous polyhydroxyalkanoate synthase enzymes can be attenuated in the host strain.

    [0202] In some embodiments using hosts that naturally accumulate lipid bodies, the genes encoding enzymes involved with lipid body synthesis are attenuated.

    [0203] In some embodiments, a L-glutamate dehydrogenase, a L-glutamine synthetase, or a glutamate synthase can be overexpressed in the host to regenerate L-glutamate from 2-oxoglutarate as an amino donor for -transaminase reactions.

    [0204] In some embodiments, enzymes such as pimeloyl-CoA dehydrogenase classified under, EC 1.3.1.62; an acyl-CoA dehydrogenase classified, for example, under EC 1.3.8.7 or EC 1.3.8.1; and/or a glutaryl-CoA dehydrogenase classified, for example, under EC 1.3.8.6 that degrade central metabolites and central precursors leading to and including C5 building blocks can be attenuated.

    [0205] In some embodiments, endogenous enzymes activating C5 building blocks via Coenzyme A esterification such as CoA-ligases (e.g., a glutaryl-CoA synthetase) classified under, for example, EC 6.2.1.6 can be attenuated.

    Producing 2,4-Pentadienoyl-CoA Using a Recombinant Host

    [0206] Typically, 2,4-pentadienoyl-CoA can be produced by providing a host microorganism and culturing the provided microorganism with a culture medium containing a suitable carbon source as described above. In general, the culture media and/or culture conditions can be such that the microorganisms grow to an adequate density and produce 2,4-pentadienoyl-CoA efficiently. For large-scale production processes, any method can be used such as those described elsewhere (Manual of Industrial Microbiology and Biotechnology, 2.sup.nd Edition, Editors: A. L. Demain and J. E. Davies, ASM Press; and Principles of Fermentation Technology, P. F. Stanbury and A. Whitaker, Pergamon). Briefly, a large tank (e.g., a 100 gallon, 200 gallon, 500 gallon, or more tank) containing an appropriate culture medium is inoculated with a particular microorganism. After inoculation, the microorganism is incubated to allow biomass to be produced. Once a desired biomass is reached, the broth containing the microorganisms can be transferred to a second tank. This second tank can be any size. For example, the second tank can be larger, smaller, or the same size as the first tank. Typically, the second tank is larger than the first such that additional culture medium can be added to the broth from the first tank. In addition, the culture medium within this second tank can be the same as, or different from, that used in the first tank.

    [0207] Once transferred, the microorganisms can be incubated to allow for the production of 2,4-pentadienoyl-CoA. Once produced, any method can be used to produce 1,3-butadiene from 2,4-pentadienoyl-CoA such as depicted in FIG. 7. The invention is further described in the following examples, which do not limit the scope of the invention described in the claims.

    EXAMPLES

    Example 1

    Enzyme Activity of Carboxylate Reductase Using Glutarate Methyl Ester as Substrate and Forming Glutarate Semialdehyde Methyl Ester

    [0208] A nucleotide sequence encoding a His-tag was added to the genes from Mycobacterium marinum, Mycobacterium smegmatis, Segniliparus rugosus, Mycobacterium massiliense, and Segniliparus rotundus that encode the carboxylate reductases of SEQ ID NOs: 2-4, 6 and 7, respectively (GenBank Accession Nos. ACC40567.1, ABK71854.1, EFV11917.1, EIV11143.1, and ADG98140.1, respectively) (see FIG. 8) such that N-terminal HIS tagged carboxylate reductases could be produced. Each of the modified genes was cloned into a pET Duet expression vector alongside a sfp gene encoding a His-tagged phosphopantetheine transferase from Bacillus subtilis, both under control of the T7 promoter. Each expression vector was transformed into a BL21[DE3] E. coli host along with the expression vectors from Example 2. Each resulting recombinant E. coli strain was cultivated at 37 C. in a 250mL shake flask culture containing 50 mL LB media and antibiotic selection pressure, with shaking at 230 rpm. Each culture was induced overnight at 37 C. using an auto-induction media.

    [0209] The pellet from each induced shake flask culture was harvested via centrifugation. Each pellet was resuspended and lysed via sonication. The cell debris was separated from the supernatant via centrifugation. The carboxylate reductases and phosphopantetheine transferase were purified from the supernatant using Ni-affinity chromatography, diluted 10-fold into 50 mM HEPES buffer (pH=7.5) and concentrated via ultrafiltration.

    [0210] The enzyme activity assay was performed in triplicate in a buffer composed of a final concentration of 50 mM HEPES buffer (pH=7.5), 2 mM glutarate methyl ester, 10 mM MgCl.sub.2, 1 mM ATP and 1 mM NADPH. The enzyme activity assay reaction was initiated by adding purified carboxylate reductase and phosphopantetheine transferase or the empty vector control to the assay buffer containing the glutarate methyl ester and then incubated at room temperature for 20 min. The consumption of NADPH was monitored by absorbance at 340 nm. The enzyme only control without glutarate methyl ester demonstrated low base line consumption of NADPH. See FIG. 9.

    [0211] The gene product of SEQ ID NO 2, 3, 6 and 7, enhanced by the gene product of sfp, accepted glutarate methyl ester as substrate as confirmed against the empty vector control (see FIG. 10) and synthesized glutarate semialdehyde methyl ester.

    Example 2

    Enzyme Activity of Pimeloyl-[acp] Methyl Ester Methylesterase Using Glutaryl-CoA Methyl Ester as Substrate and Forming Glutaryl-CoA

    [0212] A sequence encoding an C-terminal His-tag was added to the gene from Escherichia coli encoding the pimeloyl-[acp] methyl ester methylesterase of SEQ ID NO: 1 (see FIG. 8) such that C-terminal HIS tagged pimeloyl-[acp] methyl ester methylesterase could be produced. The resulting modified gene was cloned into a pET28b+ expression vector under control of the T7 promoter and the expression vector was transformed into a BL21[DE3] E. coli host. The resulting recombinant E. coli strain was cultivated at 37 C. in a 500mL shake flask culture containing 100 mL LB media and antibiotic selection pressure, with shaking at 230 rpm. Each culture was induced overnight at 18 C. using 0.3 mM IPTG.

    [0213] The pellet from each induced shake flask culture was harvested via centrifugation. Each pellet was resuspended and lysed via sonication. The cell debris was separated from the supernatant via centrifugation. The pimeloy-[acp] methyl ester methylesterase was purified from the supernatant using Ni-affinity chromatography, buffer exchanged and concentrated into 20 mM HEPES buffer (pH=7.5) via ultrafiltration and stored at 4 C.

    [0214] Enzyme activity assays converting glutaryl-CoA methyl ester to glutaryl-CoA were performed in triplicate in a buffer composed of a final concentration of 25 mM Tris.HCl buffer (pH=7.0) and 5 [mM] glutaryl-CoA methyl ester. The enzyme activity assay reaction was initiated by adding pimeloyl-[acp] methyl ester methylesterase to a final concentration of 10 [M] to the assay buffer containing the glutaryl-CoA methyl ester and incubated at 30 C. for 1 h, with shaking at 250 rpm. The formation of glutaryl-CoA was quantified via LC-MS.

    [0215] The substrate only control without enzyme showed no trace quantities of the substrate glutaryl-CoA. See FIG. 11. The pimeloyl-[acp] methyl ester methylesterase of SEQ ID NO. 1 accepted glutaryl-CoA methyl ester as substrate and synthesized glutaryl-CoA as reaction product as confirmed via LC-MS. See FIG. 11.

    Other Embodiments

    [0216] It is to be understood that while the invention has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the scope of the following claims.