Biphasic aqueous/organic biotransformation of acetaldehyde and benzaldehyde by Zymomonas mobilis pyruvate decarboxylase

Zymomonas mobilis pyruvate decarboxylase (PDC) transformed acetaldehyde and benzaldehyde into (R)‐phenylacetylcarbinol (PAC), the precursor for the synthesis of ephedrine and pseudoephedrine. Organic solvents were screened for a biphasic biotransformation with the enzyme in an aqueous phase and the toxic substrates delivered through the organic phase. In the absence of substrates a second phase of 1‐pentanol, hexadecane or MTBE (methyl tertiary‐butyl ether) stabilized the PDC activity in comparison to a control without added solvent. Organic phase solvents for optimal PAC production had partitioning coefficient (log P) values between 0.8 and 2.8 (production of more than 8 mg PAC/ U PDC), however there was no correlation between enzyme stability and log P. Best PAC formation was observed with the eight tested alcohols, which in contrast to the other solvents allowed lower initial concentrations of toxic acetaldehyde (54–81 mM) in the aqueous phase. 1‐pentanol, 1‐hexanol, and isobutanol resulted in the highest specific PAC production of 11 mg PAC /U PDC. Without the addition of an organic phase, only 1.2 mg/U was formed. © 2004 Wiley Periodicals, Inc.

[1]  V. Vojtíšek,et al.  Production of phenylacetylcarbinol in various yeast species , 1982, European journal of applied microbiology and biotechnology.

[2]  P. Rogers,et al.  Screening of yeasts for cell-free production of (R)-phenylacetylcarbinol , 2003, Biotechnology Letters.

[3]  P. Rogers,et al.  Enhanced production of R-phenylacetylcarbinol (R-PAC) through enzymatic biotransformation , 2002 .

[4]  S. Bringer-Meyer,et al.  ACETOIN AND PHENYLACETYLCARBINOL FORMATION BY THE PYRUVATE DECARBOXYLASES OF ZYMOMONAS MOBILIS AND SACCHAROMYCES CARLSBERGENSIS , 1988 .

[5]  A. Daugulis,et al.  Solvent Selection Strategies for Extractive Biocatalysis , 1991, Biotechnology progress.

[6]  B Hauer,et al.  Continuous production of (R)-phenylacetylcarbinol in an enzyme-membrane reactor using a potent mutant of pyruvate decarboxylase from Zymomonas mobilis. , 2001, Biotechnology and bioengineering.

[7]  P. Rogers,et al.  Biotransformation of benzaldehyde into (R)-phenylacetylcarbinol by filamentous fungi or their extracts , 2001, Applied Microbiology and Biotechnology.

[8]  W. Meylan,et al.  Atom/fragment contribution method for estimating octanol-water partition coefficients. , 1995, Journal of pharmaceutical sciences.

[9]  C. Laane,et al.  Rules for optimization of biocatalysis in organic solvents , 1987, Biotechnology and bioengineering.

[10]  Bernhard Hauer,et al.  Studies on the continuous production of (R)-(-)phenylacetylcarbinol in an enzyme-membrane reactor , 2001 .

[11]  M. Kula,et al.  The replacement of Trp392 by alanine influences the decarboxylase/carboligase activity and stability of pyruvate decarboxylase from Zymomonas mobilis. , 1995, European journal of biochemistry.

[12]  P. Rogers,et al.  Enzymatic (R)-phenylacetylcarbinol production in benzaldehyde emulsions , 2002, Applied Microbiology and Biotechnology.

[13]  H. Sahm.  Acetoin and Phenylacetylcarbinol Formation by the Pyruvate Decarboxylases of Zymomonas Mobilis and Saccharomyces Carlsbergensis Stephanie Bringer-Meyer , 1988 .