Table 3.

Effect of additives and co-solvents on yield and enantiomeric excess of whole-cell bioreduction of ethyl 4-cyanobenzoylformate catalyzed by E. coli XR_FDH.

substrate conc. [mM]	org. co-solvent1	additive2,3	yield [mM]4/ee [%]5
100			82/97.2 R
100		NAD+	85/97.1 R
100		polymyxin B	75/97.0 R
100		NAD+, polymyxin B	77/97.2 R
100	ethyl acetate		1/> 99.9 R
100	ethyl acetate	NAD+	9/> 99.9 R
100	hexane		3/> 99.9 R
100	hexane	NAD+	7/> 99.9 R
500			134/> 99.9 R
500		NAD+	136/> 99.9 R
500		polymyxin B	125/> 99.9 R
500		NAD+, polymyxin B	126/> 99.9 R
500	butyl acetate		9/> 99.9 R
500	butyl acetate	NAD+	35/> 99.9 R
500	BMIMPF6		74/> 99.9 R
500	BMIMPF6	NAD+	108/> 99.9 R

Conditions: 40 g_CDW/L; 8.5 h reaction time. ¹Co-solvents were added in 1:1 volume ratio. ² [NAD⁺] = 490 μM. ³ [polymyxin B sulphate] = 144 μM. ⁴Standard errors ≤ 15%. ⁵Detection limit of ethyl 4-cyanomandelate is below 0.01 mM.