Whole-cell bioreduction of aromatic α-keto esters using Candida tenuis xylose reductase and Candida boidinii formate dehydrogenase co-expressed in Escherichia coli

Table 2 Initial rates and ee-values of ethyl 4-cyanobenzoylformate reduction by different whole-cell biocatalysts.

strain	cell dry weight [g/L]	substrate conc.	initial rate [mmol/g h]¹/ee² [%]
E. coli XR_FDH	5	10	0.60/97.0 R
E. coli XR_FDH	5	100	1.12/99.0 R
E. coli XR_FDH	20	100	1.39/99.3 R
E. coli XR_FDH	40	100	1.19/98.6 R
E. coli XR_FDH	40	500	1.94/99.9 R
S. cerevisiae XR2μ ³	5	10	0.26/≥ 99.9 R
S. cerevisiae XR2μ ³	40	100	1.03/≥ 99.9 R
S. cerevisiae wild-type³	5	10	0.06/80.4 R

¹Determined from the time course of substrate conversion between 0 and ≤ 1.4 h reaction time; standard errors ≤ 20%. ² The detection limit of ethyl 4-cyanomandelate is below 0.01 mM. ³Anaerobic reaction conditions where [O₂] < 15 μM; ethanol was used as co-substrate.

ISSN: 1475-2859