Method for the oxidation of aromatic compounds
AssigneeBASF SE
InventorsAndreas Schmid, Bernhard Witholt, Bruno Buhler, Bernhard Hauer, Thomas Zelinski
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Abstract
The invention relates to a process for the biocatalytic oxidation of aromatic compounds using recombinant xylene monooxygenase-expressing microorganisms in a biphasic reaction medium.
Claims16
A process for the biocatalytic oxidation of aromatic compounds,
- which comprises
- a) growing, under aerobic conditions, a microorganism which expresses an enzyme with xylene monooxygenase (XMO) activity in a biphase aqueous-organic culture medium comprising an aromatic substrate of the formula II
- Ar—R2 (II)
- in which
- Ar is an unsubstituted or mono- or polysubstituted mononuclear aromatic ring and
- R2 is —CH═CH2, —(CH2)n+1 R3 or —(CH2)nCHO where
- n is an integer from 0 to 15;
- and
- R3 is H or OH;
- and
- b) isolating, from the culture medium, at least one product formed in the oxidation reaction.
A process as claimed in any of the preceding claims, wherein the organic phase used is an apolar organic compound with a partition coefficient of >104 in a biphasic n-octanovwater system.
A process as claimed in any of the preceding claims, wherein the organic phase has a boiling point or boiling range at 1 atm which exceeds the boiling point of the oxidation product(s) by approximately 50 to 200° C.
A process as claimed in any of the preceding claims, wherein the organic phase used is di(C5-C12-alkyl) phthalate or a mixture of such phthalates.
A process as claimed in any of the preceding claims, wherein the organic phase is separated off and the oxidation product(s) dissolved therein is/are removed by distillation.
A process as claimed in any of the preceding claims, wherein the microorganism which expresses XMO activity has essentially no benzyl alcohol dehydrogenase (BADH) activity and/or no benzaldehyde dehydrogenase (BZDH) activity.
A process as claimed in any of the preceding claims, wherein a recombinant microorganism is used which is transformed with an expression vector containing the XMO-encoding genes xylM and xylA in operable linkage under the genetic control of the regulatory alk system from Pseudomonas oleovorans GPo1.
A process as claimed in any of the preceding claims, wherein the microorganism is a bacterium from the genus Escherichia.
A process as claimed in any of the preceding claims, wherein enzyme expression is commenced by adding an inductor to the culture medium.
A process as claimed in any of the preceding claims, wherein Pseudomonas putida mt-2 xylene monooxygenase is expressed.
A process as claimed in any of the preceding claims, wherein a reaction medium is used which comprises essentially no antibiotic.
A process as claimed in any of the preceding claims, wherein the conversion is carried out as a semicontinuous batch operation.
A process as claimed in any of the preceding claims, wherein pseudocumene is used as starting material.
A process as claimed in any of the preceding claims, wherein the pH of the reaction medium is used as the parameter for the productivity of the biocatalyst.
Dependencies are inferred from the claim text.