Methods for production of oxygenated terpenes
The present invention relates to methods for producing oxygenated terpenoids. Polynucleotides, derivative enzymes, and host cells for use in such methods are also provided.
1. A method for making nootkatone comprising:
contacting valencene with a polypeptide having valencene oxidizing activity and comprising an amino acid sequence that has at least 85% sequence identity to the amino acid sequence of SEQ ID NO: 37, 38, or 55, and
recovering an oxygenated product of valencene, wherein the recovered product is at least 75% nootkatone relative to the total terpene or terpenoid content of the recovered product.
2. The method of claim 1 , wherein the polypeptide having valencene oxidizing activity comprises the amino acid sequence of SEQ ID NO: 118 at its N-terminus.
3. The method of claim 1 , wherein the polypeptide having valencene oxidizing activity has one or more mutations at positions selected from 46, 76, 94, 131, 231, 284, 383, 390, 400, 444, 468, 488, and 499 relative to the amino acid sequence of SEQ ID NO:37.
4. The method of claim 3 , wherein the polypeptide having valencene oxidizing activity has one or more mutations selected from the group consisting of R76K, M94V, T131Q, F231L, H284Q, R383K, 1390L, T468I, and T499N relative to the amino acid sequence of SEQ ID NO:37.
5. The method of claim 1 , wherein the polypeptide having valencene oxidizing activity comprises an amino acid sequence selected from the group consisting of SEQ ID NOS:55-61, 104, and 105, or an amino acid sequence selected from the group consisting of SEQ ID NOS: 55-61, 104, and 105 with no more than twenty mutations.
6. The method of claim 1 , wherein the contacting takes place in a host cell, which is a bacterium or yeast.
7. The method of claim 6 , wherein the host cell is a bacterium selected from Escherichia coli, Bacillus subtilis , or Pseudomonas putida; or a yeast selected from a species of Saccharomyces, Pichia , or Yarrowia.
8. The method of claim 6 , wherein the host cell produces isopentenyl pyrophosphate (IPP) through an endogenous or heterologous 2-C-methyl-D-erythritol 4-phosphate (MEP) or mevalonate (MVA) pathway.
9. The method of claim 8 , wherein the valencene is produced at least in part by metabolic flux through the MEP pathway, and wherein the host cell has at least one additional copy of a 1-deoxy-D-xylulose-5-phosphate synthase (dxs), 4-diphosphocytidyl-2-C-methyl-D-erythritol synthase (ispD), 2C-methyl-D-erythritol 2,4-cyclodiphosphate synthase (ispF), and/or isopentenyl diphosphate isomerase (idi) gene.
10. The method of claim 9 , wherein the host cell further expresses a farnesyl pyrophosphate synthase and a heterologous valencene synthase.
11. The method of claim 10 , wherein the valencene synthase is Citrus sinensis or Vitis vinfera valencene synthase.
12. The method of claim 10 , wherein the polypeptide having valencene oxidizing activity is expressed in a host cell that co-expresses a cytochrome P450 reductase (CPR).
13. The method of claim 12 , wherein the CPR is from Stevia sp.
14. The method of claim 10 , wherein the host cell further expresses an alcohol dehydrogenase producing nootkatone from nootkatol.
15. The method of claim 1 , wherein the recovering comprises extracting an oxidized oil comprising the oxygenated product from an aqueous reaction medium followed by fractional distillation.
16. The method of claim 15 , wherein the oxidized oil is extracted from the aqueous reaction medium using an organic solvent.
17. The method of claim 15 , wherein sesquiterpene and sesquiterpenoid components are obtained by fractional distillation of the oxidized oil and the sesquiterpene and sesquiterpenoid components are measured quantitatively by GC/MS.
18. The method of claim 17 , wherein the nootkatone fractions are recovered.
19. The method of claim 1 , further comprising a step of incorporating the recovered nootkatone into a product selected from a flavor product, a fragrance product, a cosmetic product, a cleaning product, a detergent or soap product, or a pest control product.
20. The method of claim 19 , wherein the pest control product is an insect repellant.
21. The method of claim 14 , wherein the alcohol dehydrogenase comprises an amino acid sequence that has at least 90% sequence identity to the amino acid sequence of SEQ ID NO: 84, 92, 94, 98, 100, or 102.
22. The method of claim 1 , wherein the amino acid sequence of the polypeptide having valencene oxidizing activity has at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 37, 38, or 55.