New ionic liquid increase the catalytic efficiency of recombinant Escherichia coli cells‐mediated asymmetric reduction

Abstract

Background Ionic liquids (ILs) have advantages in terms of flexible structure and composition for the whole cell mediated biocatalytic reaction. However, the lack of design strategy for ILs has hampered the development of biocatalysis in non‐aqueous medium. In the present study, to establish an efficient reaction system to obtain vital chiral compounds, a novel IL was designed by combining the superior characteristics of quaternary ammonium‐ and dialkyl‐based cationic surfactant IL to enhance the recombinant Escherichia coli cells‐catalyzed bioreduction efficiency. Results [HOEtN1,1,1][BF4] was synthesized and showed excellent characteristics of low toxicity to the biocatalyst, reduced toxicity of substrate to the microbial cells and moderate increase of cell membrane permeability. In the [HOEtN1,1,1][BF4]‐ containing reaction system, some valuable factors involved in the biocatalytic reduction of ethyl 4‐chloro‐3‐oxobutanoate to ethyl (S)‐4‐chloro‐3‐hydroxybutanoate were found to be: 2.5% (w/v) [HOEtN1,1,1][BF4], 20% (v/v) isopropanol, 3 M COBE, pH 7.0, 30 °C, reacted for 16 h. A yield of 96.7% was obtained under the optimum conditions with above 99% enantiomeric excess value, and the proposed bioprocess was also successfully scaled up to a 5 L fermentor with a yield of 90.7%. Conclusion The developed IL [HOEtN1,1,1][BF4] is a promising solvent for enhancing the efficiency of model bioreduction. It was also evaluated for broadening its application to the biosynthesis of (R)‐[3,5‐bis(trifluoromethyl)phenyl] ethanol catalyzed by recombinant Escherichia coli, with remarkable success. © 2018 Society of Chemical Industry

Design and evaluation of novel bio‐based deep eutectic solvents for highly efficient bioproduction of chiral aryl alcohol

“…Cell metabolic activity retention (MAR) was assessed with the determination of glucose consumption by the biocatalyst pretreated in different bio‐based DES‐containing medium . Specifically, the recombinant E. coli cells were vibrated on a shaking incubator at 30 °C and 200 rpm for 5 h in various 1.0% ( w / v ) bio‐based DES‐buffer mixtures in the presence or absence of 300 mmol L −1 CFPO.…”

“…Cell metabolic activity retention (MAR) was assessed with the determination of glucose consumption by the biocatalyst pretreated in different bio-based DES-containing medium. 29 Specifically, the recombinant E. coli cells were vibrated on a shaking incubator at 30 °C and 200 rpm for 5 h in various 1.0% (w/v) biobased DES-buffer mixtures in the presence or absence of 300 mmol L −1 CFPO. Subsequently, 10 g L −1 glucose was added into the mixtures and further incubated in Erlenmeyer flasks for another 3 h. After the incubation, the biological sensing analyzer (SBA-90, Shangdong Biosentech Instrument Co., Ltd, Shangdong, China) was used to determine the glucose content in different systems.…”

Biocatalysis in ionic liquids: state-of-the-union

“…Nevertheless, Du and co-workers 156 successfully developed the enantioselective reduction of ethyl-4-chloro-3-oxobutanoate to the corresponding S-alcohol, mediated by recombinant E.coli cells in water containing 2.5% 2-hydroxyethyltrimethylammonium fluoroborate, [HOCH 2 CH 2 N(CH 3 ) 3 ][BF 4 ], and 20 vol% isopropanol for cofactor regeneration (Figure 13a). The chiral alcohol product, a key intermediate in the synthesis of statin drugs such as atorvastatin, was produced on a 5L scale, with 500g/L substrate, in 97% yield and >99% ee.…”