Candidaparapsilosis CCTCC M203011 and the optimization of fermentation medium for stereoinversion of (S)-1-phenyl-1,2-ethanediol

The stereoinversion abilities of 13 species of Candida parapsilosi generally were compared. Candida parapsilosis China Center for Type Culture Collection (CCTCC) M203011 was observed to be the most suitable strain for preparation of (S)-1-phenyl-1,2-ethanediol (PED) by stereoinversion reaction. Identified by initial screening method of Plackett–Burman, the important medium components were MgSO4, ZnSO4, and KH2PO4. Response surface methodology (RSM) was applied to optimize further the preparation of (S)-PED. The optimal value for concentration of MgSO4, ZnSO4 and KH2PO4 were 1.17 g/L, 0.10 g/L and 9.41 g/L, respectively. Using this statistical optimization method, the enantioselective conversion ratio increased from 75.2% to 96.0%, while the enantiomerically excess increased from 84.2% entiomeric excess (e.e.) to 96.7% e.e.