Schalk Robert, Geoerg Daniel, Staubach Jens, Raedle Matthias, Methner Frank-Juergen, Beuermann Thomas
Institute for Process Control, Mannheim University of Applied Sciences, Paul-Wittsack-Str. 10, 68163 Mannheim, Germany.
Institute of Biotechnology, Technical University of Berlin, Chair of Brewing Science, Seestr. 13, 13353 Berlin, Germany.
J Biosci Bioeng. 2017 May;123(5):651-657. doi: 10.1016/j.jbiosc.2016.12.005. Epub 2017 Jan 3.
A mid-infrared (MIR) sensor using the attenuated total reflection (ATR) technique has been developed for real-time monitoring in biotechnology. The MIR-ATR sensor consists of an IR emitter as light source, a zinc selenide ATR prism as boundary to the process, and four thermopile detectors, each equipped with an optical bandpass filter. The suitability of the sensor for practical application was tested during aerobic batch-fermentations of Saccharomyces cerevisiae by simultaneous monitoring of glucose and ethanol. The performance of the sensor was compared to a commercial Fourier transform mid-infrared (FT-MIR) spectrometer by on-line measurements in a bypass loop. Sensor and spectrometer were calibrated by multiple linear regression (MLR) in order to link the measured absorbance in the transmission ranges of the four optical sensor channels to the analyte concentrations. For reference analysis, high-performance liquid chromatography (HPLC) was applied. Process monitoring using the sensor yielded in standard errors of prediction (SEP) of 6.15 g/L and 1.36 g/L for glucose and ethanol. In the case of the FT-MIR spectrometer the corresponding SEP values were 4.34 g/L and 0.61 g/L, respectively. The advantages of optical multi-channel mid-infrared sensors in comparison to FT-MIR spectrometer setups are the compactness, easy process implementation and lower price.
一种采用衰减全反射（ATR）技术的中红外（MIR）传感器已被开发用于生物技术中的实时监测。该MIR-ATR传感器由作为光源的红外发射器、作为与过程边界的硒化锌ATR棱镜以及四个均配备有光学带通滤波器的热电堆探测器组成。通过同时监测葡萄糖和乙醇，在酿酒酵母的好氧分批发酵过程中测试了该传感器在实际应用中的适用性。通过在旁路回路中的在线测量，将该传感器的性能与商用傅里叶变换中红外（FT-MIR）光谱仪进行了比较。传感器和光谱仪通过多元线性回归（MLR）进行校准，以便将四个光学传感器通道传输范围内测得的吸光度与分析物浓度联系起来。作为参考分析，采用了高效液相色谱法（HPLC）。使用该传感器进行过程监测时，葡萄糖和乙醇的预测标准误差（SEP）分别为6.15 g/L和1.36 g/L。对于FT-MIR光谱仪，相应的SEP值分别为4.34 g/L和0.61 g/L。与FT-MIR光谱仪设置相比，光学多通道中红外传感器的优点是紧凑、易于在过程中实施且价格较低。
