发酵工艺中的高温蒸气灭菌过程使得传统"酶膜"方式葡萄糖生物传感器不能在线使用,导致不能实时控制葡萄糖的补加量,进而影响发酵的质量和产率。为了解决这一问题,本研究构建了一套用于发酵过程的葡萄糖在线检测系统。利用研制的耐高温的"酶液"方式葡萄糖生物传感器解决了"酶膜"方式传感器高温后无法正常工作的问题;利用研制的耐高温的透析取样系统解决了在线取样难题。实验表明:本传感器对葡萄糖的灵敏度达到0.259 nA/(mg/L);检出限为0.7 mg/L。对于500 mg/L葡萄糖浓度测量结果的相对标准偏差为2.02%;在0~1000 mg/L范围内,系统响应信号与葡萄糖浓度呈线性关系;本系统与商品化SBA-40E生物传感分析仪离线测量结果相比,呈现显著的线性相关关系。且线性相关方程的斜率k≈1。利用此检测系统对大肠杆菌发酵过程中的葡萄糖浓度进行了在线测量,并与SBA-40E生物传感分析仪离线测量结果进行了对比,变化趋势基本一致。
Due to the high temperature steam sterilization in the fermentation process,traditional "enzyme membrane" glucose biosensors are no longer suitable for online glucose detection.This leads to failure of real-time glucose feeding control,consequently affecting the quality and yields of fermentation.In order to solve this problem,a glucose on-line detection system for monitoring the fermentation process was set up.The problem was solved by using a self-developed "enzyme solution" glucose biosensor which stands high temperature.Another difficult problem about on-line sampling was solved by using a self-developed dialysis sampling system which also stands high temperature.Experimental results show that the sensitivity of the sensor is 0.259 nA/(mg/L),the detection limit is 0.7 mg/L and the RSD is 2.0% at the glucose concentration of 500 mg/L,and that the system responds linearly to the glucose concentration in the range of 0-1000 mg/L.These results were compared with those on a commercial off-line SBA-40E Biosensing analyzer,exhibiting an excellent linear correlation with the linear coefficient close to 1.Glucose concentration was measured on-line in the coli fermentation process with the detection system,and the results exhibit the same variation trend to the commercial off-line SBA-40E Biosensing Analyzer.