Highly enantioselective hydrolysis of dl-menthyl acetate to l-menthol by whole-cell lipase from Burkholderia cepacia ATCC 25416

Enzymatic hydrolysis of dl-menthyl acetate to l-menthol by whole-cell lipase had been carried out in this work. Burkholderia cepacia ATCC 25416 was selected as the efficient experiment strain. Effects of various reaction parameters such as pH, temperature, substrate concentration and co-solvents on the conversion as well as enantioselectivity were studied. A high enantiomeric ratio (E = 170) was achieved when 15% (v/v) dimethyl sulfoxide (DMSO) was added, the enantioselectivity was about 3.0-fold higher than that without co-solvent. l-Menthol was obtained with 96% optical purity and 50% conversion under the optimum conditions. Burkholderia cepacia whole-cell lipase also exhibited high reaction capacity and good operational stability. The tolerable substrate concentration was 0.23 mol/L; the half-life of activity at 30 °C was about 400 h.