S. Bormann, M. M. W. Etschmann, M.-A. Mirata, J. Schrader
Linalool oxides are of interest to the flavour industry because of their lavender notes.Corynespora cassiicola DSM 62475 has been identified recently as a production organism because of high stereoselectivity and promising productivities [Mirata et al. (2008) J Agric Food Chem 56(9):3287–3296]. In this work, the stereochemistry of this biotransformation was further investigated. Predominantly (2R)-configured linalool oxide enantiomers were produced from (R)-(−)-linalool. Comparative investigations with racemic linalool suggest that predominantly (2S)-configured derivatives can be expected by using (S)-(+)-configured substrate. Substrate and product inhibited growth even at low concentrations (200 mg l−1). To avoid toxic effects and supply sufficient substrates, a substrate feeding product removal (SFPR) system based on hydrophobic adsorbers was established. Applying SFPR, productivity on the shake flask scale was increased from 80 to 490 mg l−1 day−1. Process optimisation increased productivity to 920 mg l−1 day−1 in a bioreactor with an overall product concentration of 4.600 mg l−1 linalool oxides.