The Preparation Of Chiral 1,2-Propanediol By Bioconversion And Bioresolution

A strain was screened which can selectively decompose the racemic 1,2-propanediol. The results of experiment suggested that, when the concentration of racemic 1,2-propanediol was 0.292 mmol/ml, (R)-1,2-propanediol was completely consumed, but (S)-1,2-propanediol was remained.(R)-1,2-propanediol can be obtained by reduction of acetol with Bakers Yeast. This paper groped the optimum condition of the process. We found ethanol was the very effective substance which could make co-enyzme regenerate. The optimum condition of the process was : the time for transformation was 25 hours, the concentration of acetol, ethanol, baker's yeast was 0.154mmol/ml ,150g/L, 0.339mmol/ml; pH was 7.0. Based on the data, the large-scale preparation of (R)-1,2-propanediol in 1.5L fermenter was studied. Through batch-feeding acetol and ethanol, (R)-1,2-propanediol was obtained. The concentration , yield and ee were 0.278mmol/ml, 62.3% , 100% respectively.This paper studied the resolution of racemic 1,2-propanediol with bakers yeast. The main content was to research the effects of the reactive condition. The results demonstrated that concentration of acetol was increasing with the increase of the oxygenic supply and racemic 1,2-propanediol. But the yield decreased with the increase of concentration of racemic 1,2-propanediol. When pH was in the range of 4 ~9.5, no effect was on the concentration of product.