Propioin synthesis using thiamine diphosphate-dependent enzymes

✍ Scribed by Renaud J. Mikolajek; Antje C. Spiess; Martina Pohl; Jochen Büchs

• Publisher: American Institute of Chemical Engineers
• Year: 2009
• Tongue: English
• Weight: 124 KB
• Volume: 25
• Category: Article
• ISSN: 8756-7938
• DOI: 10.1002/btpr.55

✦ Synopsis

Abstract

Benzaldehyde lyase (BAL, EC 4.1.2.38) from Pseudomonas fluorescens and benzoylformate decarboxylase (BFD, EC 4.1.1.7) from Pseudomonas putida are thiamine diphosphate‐dependent enzymes. These enzymes share a common tetrameric structure and catalyze various CC‐bond forming and breaking reactions. Here we describe a detailed study of the asymmetric synthesis of propioin from propanal catalyzed by BAL or BFD in aqueous solution in a batch reactor. Both enzymes are deactivated in the presence of high concentration of propanal. Compared to BAL, BFD is more stable under reaction conditions as well as during storage. The kinetic studies showed a typical Michaelis‐Menten kinetic for BAL with a maximal specific reaction rate of 26.2 U/mg and an unusually high K~M~ of 415 mM, whereas the v/[S]‐plot for BFD is almost linear in the concentration range (100–1500 mM) investigated. Both enzymes produce propioin with opposite enantiomeric excess: BAL produced the (S)‐propioin (ee of 35%), whereas BFD yielded the (R)‐enantiomer (ee of 67%). © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009