Abstract:In this paper， the effects of medium composition on the catalysis ability of whole cells of Aspergillus niger C2J6 biocatalyst were compared， and the optimal conditions for the synthesis of ethyl lactate by whole cell catalysis in a non-aqueous phase were determined by single factor test and response surface optimization test. The results showed that the whole cell had the highest catalytic activity when cultured at 28 ℃ and 150 r/min for 24 h in a liquid culture medium. The optimal conditions for synthesis of ethyl lactate were as follows： reaction medium tert-butanol of 5 mL， substrate molar ratio （lactic acid and anhydrous ethanol） of 1∶5， lactic acid concentration of 0.3 mol/L （based on the volume of the reaction medium）， whole cell concentration of 35 g/mol （based on the amount of lactic acid substance）， and reaction at 40 ℃ and 150 r/min for 24 h. The yield of ethyl lactate was the highest （29.86%）. The synthesis of ethyl lactate by whole cell catalysis was consistent with the quasi-first-order kinetic model， and the catalytic efficiency decreased gradually after the whole cell was reused for three times， and the esterification rate was only 2.90%.