海藻糖与赤藓糖醇偶联发酵工艺研究

Optimization of coupling fermentation process of trehalose and erythritol

对陶瓷膜过滤后的海藻糖糖化液进行成分分析,确定主要成分及营养指标。结合成分分析结果,补加氮源进行偶联发酵并对氮源补加量进行优化,在确定的最佳氮源添加量下进行小试工艺的研究与优化。结果表明,偶联发酵最适氮源补加量为酵母浸膏、酵母浸粉各3 g/L;偶联发酵能够实现消耗葡萄糖的目的,发酵72 h,对照组及补氮组残糖分别降至0.09 g/L、0.05 g/L。此外,补充氮源提升了赤藓糖醇得率,但赤藓糖醇水平较低,仅为25.4 g/L,糖醇转化率为30.70%。在补充氮源的基础上,向底料培养基补加葡萄糖至终浓度200 g/L进行发酵,赤藓糖醇得率大幅度提升,发酵液赤藓糖醇浓度提升至104.62 g/L,糖醇转化率50.18%,较优化前分别提升了97.32 g/L,42.26%。该优化偶联发酵工艺降低了下游海藻糖分离纯化的难度,提高了海藻糖的生产效益。本研究为其他稀有糖的生产提供了新的思路。

The trehalose saccharification solutionfiltered by ceramic membrane were analyzed to determine its main components and nutrients.Based on the results of composition analysis,the nitrogen source was added for coupling fermentation of trehalose and erythritol and the amount of nitrogen source addition was optimized.With the optimal addition amount of nitrogen source,the small-scale process was studied and optimized.The results showed that the optimum nitrogen source addition amount for coupling fermentation was 3 g/L of yeast extract and 3 g/L of yeast powder respectively;the coupling fermentation could achieve the goal of consuming glucose.After 72 hours of fermentation,the residual sugar in the control group and the nitrogen supplement group decreased to 0.09 g/L and 0.05 g/L respectively.In addition,nitrogen supplement increased the yield of erythritol,but the level of erythritol was low,only 25.4 g/L,and the conversion rate of sugar to erythritol was 30.70%.On the basis of nitrogen source supplement,glucose was added to the fermentation medium to the final concentration of 200 g/L and the yield of erythritol was significantly increased.The concentration of erythritol in the fermentation broth was increased to 104.62 g/L,and the conversion rate from glucose to erythritol was 50.18%,it was 97.32 g/L and 42.26%higher than that before the fermentation optimization respectively.The optimized coupling fermentation process reduced the difficulty of downstream trehalose’s separation and purification,improved the production efficiency of trehalose.This study provides a new idea for the production of other rare sugars.