TY - JOUR
T1 - Bioprocess design guided by in situ substrate supply and product removal: Process intensification for synthesis of (S)-1-(2-chlorophenyl)ethanol
AU - Schmoelzer, Katharina
AU - Mädje, Katharina Teresa
AU - Nidetzky, Bernd
AU - Kratzer, Regina
PY - 2012
Y1 - 2012
N2 - We report herein on bioprocess development guided by the hydrophobicities of substrate and product. Bioreductions of o-chloroacetophenone are severely limited by instability of the catalyst in the presence of aromatic substrate and (S)-1-(2-chlorophenyl)ethanol. In situ substrate supply and product removal was used to protect the utilized Escherichia coli whole cell catalyst based on Candida tenuis xylose reductase during the reaction. Further engineering at the levels of the catalyst and the reaction media was matched to low substrate concentrations in the aqueous phase. Productivities obtained in aqueous batch reductions were 21-fold improved by addition of 20% (v/v) hexane, NAD+, expression engineering, cell permeabilization and pH optimization. Reduction of 300 mM substrate was accomplished in 97% yield and use of the co-solvent hexane in subsequent extraction steps led to 88% recovery. Product loss due to high catalyst loading was minimized by using the same extractant in bioreduction and product isolation.
AB - We report herein on bioprocess development guided by the hydrophobicities of substrate and product. Bioreductions of o-chloroacetophenone are severely limited by instability of the catalyst in the presence of aromatic substrate and (S)-1-(2-chlorophenyl)ethanol. In situ substrate supply and product removal was used to protect the utilized Escherichia coli whole cell catalyst based on Candida tenuis xylose reductase during the reaction. Further engineering at the levels of the catalyst and the reaction media was matched to low substrate concentrations in the aqueous phase. Productivities obtained in aqueous batch reductions were 21-fold improved by addition of 20% (v/v) hexane, NAD+, expression engineering, cell permeabilization and pH optimization. Reduction of 300 mM substrate was accomplished in 97% yield and use of the co-solvent hexane in subsequent extraction steps led to 88% recovery. Product loss due to high catalyst loading was minimized by using the same extractant in bioreduction and product isolation.
U2 - 10.1016/j.biortech.2012.01.009
DO - 10.1016/j.biortech.2012.01.009
M3 - Article
SN - 1873-2976
VL - 108
SP - 216
EP - 223
JO - Bioresource Technology
JF - Bioresource Technology
ER -