Method for the enzymatic production of 3-hydroxy-3-methylbutyric acid from acetone and acetyl-coa
Described is a method for the production of 3-hydroxy-3-methylbutyric acid by enzyme-catalyzed covalent bond formation between the carbon atom of the oxo group of acetone and the methyl group of a compound which provides an activated acetyl group. Also described are recombinant organisms which produce 3-hydroxy-3-methylbutyric acid, and related compositions and methods.
1. A method for the production of 3-hydroxy-3-methylbutyric acid consisting essentially of:
(a) providing a recombinant microorganism which has been transformed with a polynucleotide encoding 3-hydroxy-3-methylglutaryl-CoA (HMG CoA) synthase and a polynucleotide encoding acetoacetate decarboxylase, wherein at least one of the polynucleotides is heterologous to the recombinant microorganism; and
(b) incubating, in the recombinant microorganism (i) acetone and (ii) a compound of formula (I) which provides an activated acetyl group:
wherein X is S—CH 2 —CH 2 —NH—CO—CH 2 —CH 2 —NH—CO—CH(OH)—C(CH 3 ) 2 —CH 2 —O—PO 2 H—PO 2 H—C 10 H 13 N 5 O 7 P (coenzyme A),
with (c) the HMG CoA synthase,
under conditions in which the recombinant microorganism produces acetone and expresses the HMG CoA synthase,
thereby producing 3-hydroxy-3-methylbutyric acid.
2. The method of claim 1 , wherein the microorganism naturally has the capacity to produce acetone.
3. The method of claim 2 , wherein the microorganism is of the genus Clostridium, Bacillus or Pseudomonas.
4. The method of claim 3 , wherein the microorganism is selected from the species Clostridium acetobutylicum, Clostridium beijerinckii, Clostridium cellulolyticum, Bacillus polymyxa , and Pseudomonas putida.
5. The method of claim 1 , wherein the microorganism is of a species which naturally does not produce acetone.
6. The method of claim 5 , wherein the microorganism is capable of photosynthesis.
7. The method of claim 1 , wherein the microorganism is Escherichia coli.
8. The method of claim 1 , wherein the microorganism is selected from Saccharomyces, Schizosaccharomyces, Aspergillus and Trichoderma.