Enzymatic characterization of a recombinant carbonyl reductase from Acetobacter sp. CCTCC M209061

Bioresources and Bioprocessing

Table 3 The relative activity of the recombinant AcCR to catalyze the oxidation of alcohols and reduction of ketones

Substrate	Relative activity (%)	Substrate	Relative activity (%)
Isopropanol	45.4
1-Phenethyl alcohol	Nd	Acetophenone	9.2
1-(4-Methylphenyl)ethanol	16.6	4-Methylacetophenone	16.5
2-Methoxyphenethyl alcohol	1.9	2-Methoxyacetophenone	3.1
3-Methoxyphenethyl alcohol	7.7	3-Methoxyacetophenone	10.7
4-Methoxyphenethyl alcohol	11.6	4-Methoxyacetophenone	5.1
3,3-Dimethyl-2-butanol	36.5	3,3-dimethyl-2-butanone	47.5
1-(Trimethylsilyl)-ethanol	Nd	1-(Trimethylsilyl)ethanone	156.5
4-(Trimethylsilyl)-3-butyn-2-ol	2.9	4-(Trimethylsilyl)-3-butyn-2-one	114.4
Methyl 3-hydroxybutyrate	13.1	Methyl acetoacetate	81.1
Ethyl 3-hydroxybutyrate	6.2	Ethyl acetoacetate	52.1
Ethyl (R)-4-chloro-3-hydroxybutyrate	Nd	Ethyl-4-chloroacetoacetate	120.6
Ethyl (S)-4-chloro-3-hydroxybutyrate	Nd	Ethyl-4-chloroacetoacetate	120.6
1-(4-Fluorophenyl)ethanol	55.1	4-Fluoroacetophenone	85.1
1-(4-Chlorophenyl)ethanol	52.3	4-Chloroacetophenone	100.0
1-(4-Bromophenzyl) alcohol	44.2	4-Bromoacetophenone	117.1
1-(4-Nitrophenzyl) alcohol	49.6	4-Nitroacetophenone	98.7
2-Pentanol	98.6	2-pentanone	158.6
2- (R)-Octanol	107.7	2-Octanone	87.58
2- (S)-Octanol	2.9	2-Octanone	87.58
Ethyl 2-hydroxy-4-phenylbutyrate	2.3	Ethyl 2- oxo-4-phenylbutyrate	35.8

Reaction conditions: for oxidation reaction (a) 0.5 mM NAD⁺, 2 mL 50 mM Tris–HCl buffer (pH 8.5), 50 mM alcohol compound incubated at 45 °C for 5 min before adding 20 μL purified recombinant AcCR (about 0.008 mg the purified enzyme), recorded the changes of absorbance for 3 min at 45 °C; for reduction reaction (b) 0.25 mM NADH, 2 mL 50 mM citrate–phosphate buffer (pH 6.5), 50 mM carbonyl compound at 35 °C for 5 min before adding 20 μL purified recombinant AcCR (about 0.008 mg the purified enzyme) recorded the changes of absorbance for 3 min at 35 °C