초록
The effect of osmotic pressure on erythritol and mannitol production by an osmophilic yeast strain of Yarrowia lipolytica CICC 1675 using glycerol as the sole carbon source was investigated. Appropriately high osmotic pressure was found to enhance erythritol production and inhibit mannitol formation. A novel two-stage osmotic pressure control fed-batch strategy based on the kinetic analysis was developed for higher erythritol yield and productivity. During the first 96h, the osmotic pressure was maintained at 4.25osmol/kg by feeding glycerol to reduce the inhibition of cell growth. After 132h, the osmotic pressure was controlled at 4.94osmol/kg to maintain a high dp<SUB>ery</SUB>/dt. Maximum erythritol yield of 194.3g/L was obtained with 0.95g/L/h productivity, which were 25.7% and 2.2%, respectively, improvement over the best results in one-stage fed-batch fermentation. This is the first report that a novel osmotic pressure control fed-batch strategy significantly enhanced erythritol production.