Biocatalytic anti-Prelog reduction of prochiral ketones with whole cells of a newly isolated strain Empedobacter brevis ZJUY-1401

• A novel whole-cell biocatalyst with anti-Prelog stereoselectivity was reported.
• Activity and selectivity of the biocatalyst were notablely enhanced by 10% ethanol.
• The whole-cell biocatalyst showed strong tolerance against 10% ethanol.
• The biocatalyst exhibited excellent performance over a broad pH range of 6.0–9.5.
• The biocatalyst showed a broad substrate spectrum and excellent selectivity (>99% ee).

Robust biocatalysts are in high demand for the reduction of prochiral ketones to anti-Prelog chiral alcohols. A recently isolated bacterial strain ZJUY-1401 exhibited high reduction activity and excellent anti-Prelog stereospecificity toward prochiral ketones. Based on the colony and microscopic morphology, physiological tests, and 16S rDNA sequence, the isolate was identified as Empedobacter brevis. Upon addition of either NADH or NADPH, the whole cells of E. brevis ZJUY-1401 showed enhanced catalytic activity. The activity and stereoselectivity of the biocatalyst toward acetophenone were significantly increased in the presence of 10% (v/v) ethanol as cosubstrate. Important properties concerning the application of E. brevis ZJUY-1401 include the excellent catalytic performance over a broad pH range from 6.0 to 9.5, temperature optimum of 35 °C, and noticeable tolerance against ethanol. Under the optimal conditions, E. brevis ZJUY-1401 was highly active for the reduction of acetophenone derivatives, giving corresponding alcohols in excellent enantiomeric purity (>99% ee). These results imply that E. brevis ZJUY-1401 is a promising biocatalyst for the preparation of anti-Prelog chiral alcohols.

Empedobacter brevis ZJUY-1401, a novel whole-cell biocatalyst with excellent anti-Prelog stereoselectivity, was for the first time successfully applied in the asymmetric reduction of prochiral ketones.Figure optionsDownload as PowerPoint slide