不同时间添加氮源对酵母GJ2008果糖与葡萄糖利用的影响

Effect of the timing of nitrogen addition on fructose and glucose utilization during ethanol fermentation by Saccharomyces cerevisiae GJ2008

甘蔗汁被完全酸水解后,添加等量果糖与葡萄糖调整总糖浓度为220g/L,对此水解液进行酒精发酵,并在发酵过程的不同时间点添加氮源。采用高效液相色谱法测定发酵过程中果糖和葡萄糖含量,通过曲线下面积法对果糖与葡萄糖代谢曲线进行分析。结果表明:酵母GJ2008始终会优先利用葡萄糖,果糖的利用滞后;在12 h前添加氮源可有效地缩小果糖与葡萄糖利用的差异性。

In the present study, completely hydrolyzed sugarcane juice containing total sugar content of 140 g/L was adjusted with an equivalent amount of fructose and glucose to give a total sugar concentration of 220 g/L. Then the juices were supplemented with nitrogen sources at various stages, and used as ethanol production medium. The fructose and glucose concentrations were determined by HPLC （high performance liquid chromatography）. Area under the curve （AUC） of fermentation of fructose and glucose was obtained using GraphPad Prism 5 software to analyze the discrepancy in fructose and glucose consumption. Results indicated that S. cerevisiae GJ2008 always showed a slightly higher preference for glucose than fructose, and fructose consumption always lagged behind glucose consumption. Nitrogen addition could reduce the discrepancy in glucose and fructose utilization effectively when it was added in the early stages of the fermentation.