毛细管电泳紫外检测聚谷氨酸发酵液中蔗糖浓度

DETERMINATION OF SUCROSE IN POLY-γ-GLUTAMIC ACID FERMENTATION LIQUOR BY CAPILLARY ELECTROPHORESIS WITH UV DETECTION

建立了测定发酵液中蔗糖浓度的新方法——毛细管电泳紫外法。考察了该方法中背景缓冲液的选择、分离电压、温度等因素对样品响应值和迁移时间的影响，获得了优化的电泳工作条件。最佳的操作条件为：以30mmol·L^-1、pH11．0的对氨基水杨酸作为背景缓冲液，分离电压15kV，操作温度25℃。在此条件下，电泳分离在6．66min内完成，标准曲线的线性范围为0．078～20g·L^-1、r为0．9998、检出限为0．035g·L^-1。应用该方法测定聚谷氨酸发酵过程中不同生长时期蔗糖浓度和消耗曲线。

A method of capillary electrophoresis with UV detection was established for the determination of sucrose in poly-γ-glutamic acid （γ-PGA） fermentation liquor. Effects of running buffer and its concentration, separation voltage and temperature on the retention time and signal response were investigated. Optimized working conditions were described as follows, aminosalicylic acid （30 mmol · L^-1 pH 11. 0） as the running buffer, separation voltage. 15 kV, operating temperature. 25 ℃. Electrophoresis separation was performed within 6. 66 min Linearity of the calibration curve was in range of 0. 078～20 g · L^-1 with a detection limit of 0. 035 g · L^-1 and r 0. 999 8. The method has been applied to the mapping of the sucrose consumption curve and determination of concentration of sucrose at different growing stage during the course of fermentation of γ-PGA.