Host cells and methods for producing alkyl lactone by cyclization of hydroxyl fatty acid
View Patent ↗This present invention provides for a genetically modified host cell, or a cell-free reaction system, and related methods and materials for the biocatalytic production of an alkyl lactones from a hydroxy fatty acid, or natural alkyl lactones and esters from sugars using non-natural combinations of enzymes.
1. A genetically modified host cell comprising: a chimeric fusion comprising (a) (i) an acyl-acyl-carrier protein synthetase (AAS), fatty acyl-AMP ligase (FAAL), or fatty acyl-coenzyme A ligase (FACL) which converts a carboxyl of a hydroxy fatty acid into a thioester, and (ii) an esterase or thioesterase which converts the thioester into an alkyl lactone, or (b) (i) a FACL which converts the hydroxy fatty acid into a coenzyme A-bound thioester, and (ii) a mycobacteria PapA5 or wax ester synthase which converts the coenzyme A-bound thioester into an alkyl lactone; wherein the genetically modified host cell is a Saccharomyces, Escherichia, Corynebacterium, Pseudomonas, Streptomyces , and Bacillus cell .
2. The genetically modified host cell of claim 1 , wherein the hydroxy fatty acid is a saturated hydroxy fatty acid or an unsaturated hydroxy fatty acid.
3. The genetically modified host cell of claim 2 , wherein the saturated
hydroxy fatty acid has the following chemical structure:
wherein n is an integer from one to 20, and R is -H or an akyl chain having a chain length of C1 to C10.
4. The genetically modified host cell of claim 3 , wherein n is an integer from one to 14.
5. The genetically modified host cell of claim 2 , wherein the unsaturated
hydroxy fatty acid has the following chemical structure:
wherein m is an integer from one to 20, n is an integer from one to 20, and R is H or an akyl chain having a chain length of C1 to C10.
6. The genetically modified host cell of claim 5 , wherein m is an integer from one to 14, n is an integer from zero to 13, and m+n=14.
7. The genetically modified host cell of claim 1 , wherein the chimeric fusion comprises a cyclizing thioesterase (cycTE) enzyme.
8. The genetically modified host cell of claim 1 , wherein the chimeric fusion comprises a mycobacteria PapA5, or a wax ester synthase enzyme.
9. The genetically modified host cell of claim 1 , wherein host cell is a yeast or Escherichia coli .
10. The genetically modified host cell of claim 1 , wherein host cell is capable of producing one or more alkyl lactone from glucose, acetate, propionate or glycerol, or a combination thereof.
11. The genetically modified host cell of claim 2 , wherein the unsaturated hydroxy acid is polyunsaturated.
12. A genetically modified host cell comprising: a chimeric fusion comprising (i) an acyl-acyl-carrier protein synthetase (AAS), which converts a carboxyl of a hydroxy fatty acid into a thioester, and (ii) an esterase or thioesterase which converts the thioester into an alkyl lactone; wherein the genetically modified host cell is a yeast or cell, and the chimeric fusion comprises a Vibrio harveyii AAS depicted in SEQ ID NO:1 or a Gibberella zeae thioesterase depicted in SEQ ID NO:2.
13. The genetically modified host cell of claim 12 , wherein the chimeric fusion comprises a Gibberella zeae thioesterase depicted in SEQ ID NO:2.
14. The genetically modified host cell of claim 12 , wherein the chimeric fusion comprises a Vibrio harveyii AAS depicted in SEQ ID NO:1.