Methods and microorganisms for producing flavors and fragrance chemicals
The present disclosure relates to biosynthetic pathways for producing flavor and fragrance chemicals, such as green notes including trans-2-unsaturated aldehydes and lactones. The present disclosure provides methods for producing trans-2-unsaturated aldehydes, delta-lactones, and gamma-lactones. The present disclosure provides pathways for the preparation of trans-2-unsaturated aldehydes, delta-lactones, and gamma-lactones by reacting aldehydes in the presence of aldolases.
1. A non-naturally occurring microorganism having a trans-2-unsaturated aldehyde pathway, wherein the non-naturally occurring microorganism is transformed with an exogenous nucleic acid encoding an aldolase comprising the amino acid sequence of SEQ ID NOs: 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, an exogenous nucleic acid encoding a decarboxylase comprising the amino acid sequence of SEQ ID NOs: 68, 71, 76, or 77 and an exogenous nucleic acid encoding an aldo-ketoreductase comprising the amino acid sequence of SEQ ID NOs: 30, 31, 32, or 33, wherein the non-naturally occurring microorganism produces a trans-2-unsaturated aldehyde.
2. The non-naturally occurring microorganism of claim 1 , wherein the non-naturally occurring microorganism comprises an increased enzymatic activity of at least one enzyme in said trans-2-unsaturated aldehyde pathway in comparison with the enzymatic activity of the same enzyme in a corresponding unmodified or wild-type microorganism.
3. The non-naturally occurring microorganism of claim 1 , wherein the non-naturally occurring microorganism further comprises an exogenous nucleic acid encoding a ketoreductase, oxidoreductase, aldehyde reductase, enoate reductase, dehydratase, lactonization enzyme, or alcohol dehydrogenase.
4. The non-naturally occurring microorganism of claim 1 , wherein the decarboxylase comprises the amino acid sequence of SEQ ID NO: 71.
5. The non-naturally occurring microorganism of claim 1 , wherein the decarboxylase comprises the amino acid sequence of SEQ ID NO: 76.
6. The non-naturally occurring microorganism of claim 1 , wherein the decarboxylase comprises the amino acid sequence of SEQ ID NO: 68 or 77.
7. The non-naturally occurring microorganism of claim 1 , wherein the non-naturally occurring microorganism further comprises an exogenous nucleic acid encoding an, ethylnitronate:oxygen 2-oxidoreductase (nitriteforming), pyruvate carboxy-lyase (acetaldehyde-forming), acetaldehyde:NAD+ oxidoreductase (CoA-acetylating), acetaldehyde:acceptor oxidoreductase, Acetaldehyde:NAD+ oxidoreductase, Acetaldehyde:NADP+ oxidoreductase, Ethanol:NADP+ oxidoreductase, 2-Phosphonoacetaldehyde phosphonohydrolase, ethanolamine-phosphate phosphate-lyase (deaminating; acetaldehyde-forming), ethanolamine ammonia-lyase (acetaldehyde-forming), 4-hydroxy-2-oxopentanoate pyruvate-lyase (acetaldehyde-forming), L-threonine acetaldehyde-lyase (glycine-forming), (S)-lactate acetaldehyde-lyase (formate-forming), ethanol:NAD+ oxidoreductase, Pyruvate decarboxylase, TPP dependent reaction, Nitroethane:oxygen oxidoreductase, acetaldehyde:pyrroloquinoline-quinone oxidoreductase, 2-deoxy-D-ribose-S-phosphate acetaldehyde-lyase (D-glyceraldehyde-3-phosphate-forming), 17alpha-Hydroxyprogesterone acetaldehyde-lyase, 3-Hydroxybutan-2-one:D-ribose-5-phosphate aldehydetransferase, 24R,24(1)R)-fucosterol-epoxide acetaldehyde-lyase (desmosterol-forming), ethanol:cytochrome c oxidoreductase, acetaldehyde hydro-lyase, diethanolamine ethanolamine-lyase (acetaldehyde-forming), triethanolamine diethanolamine-lyase (acetaldehyde-forming), L-allo-threonine acetaldehyde-lyase (glycine-forming), fluoroacetaldehyde:L-threonine aldehydetransferase, cobalt-precorrin 5A acylhydrolase, D-threonine acetaldehyde-lyase (glycine-forming), 17alpha-Hydroxypregnenolone acetaldehyde-lyase, ethanol:cytochrome c oxidoreductase, chloroethane, donor:oxygen oxidoreductase (dechlorinating, acetaldehydeforming), ethanol:quinone oxidoreductase, acetyl-CoA:acetoin O-acetyltransferase, ethanol:N,N-dimethyl-4-nitrosoaniline oxidoreductase, 7,8-dihydroneopterin 3′-triphosphate acetaldehyde-lyase (6-carboxy-5,6,7,8-tetrahydropterin and triphosphate-forming), or choline trimethylamine-lyase (acetaldehyde-forming).
8. The non-naturally occurring microorganism of claim 1 , wherein one or more genes encoding an enzyme that utilizes pyruvate are deleted from the non-naturally occurring microorganism as compared to a wild-type microorganism.
9. The non-naturally occurring microorganism of claim 1 , wherein one or more genes encoding an enzyme capable of catalyzing a reaction involving an acetaldehyde molecule, a pyruvate, or an aldehyde precursor are deleted from the non-naturally occurring microorganism as compared to a wild-type microorganism.
10. The non-naturally occurring microorganism of claim 8 , wherein the trans-2-unsaturated aldehyde is trans-2-hexenal.