Integrated bioprocess for the stereospecific production of linalool oxides from linalool with Corynespora cassiicola DSM 62475
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.