Horvath J J, Glazier S A, Spangler C J
Biotechnology Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899.
Biotechnol Prog. 1993 Nov-Dec;9(6):666-70. doi: 10.1021/bp00024a016.
This work describes a new spectroscopic optical fiber/rod technique for in situ real time measurement of cell mass and product concentrations in bioreactors using intrinsic fluorescence. The variable excitation/emission wavelength capability of this sensor allows for species-selective measurement during fermentations. Cell mass (tryptophan) and product concentrations (pyridoxine) have been measured during fermentations of Saccharomyces cerevisiae. The effects of varying substrate concentration and oxygen concentration on the observed cell mass signals are eliminated by direct measurement of cell mass, as opposed to indirect measurement schemes such as those using NADH fluorescence. The sensor is robust and able to undergo many cycles of in situ steam sterilization without degradation, and its fluorescence signal is linear with concentration for all species studied in this work. Tryptophan fluorescence from yeast is shown to be a better measure of cell mass than NADH fluorescence.
这项工作描述了一种新的光谱光纤/棒技术，用于利用固有荧光对生物反应器中的细胞质量和产物浓度进行原位实时测量。该传感器可变的激发/发射波长能力使得在发酵过程中能够进行物种选择性测量。在酿酒酵母发酵过程中，已经对细胞质量（色氨酸）和产物浓度（吡哆醇）进行了测量。与使用NADH荧光等间接测量方案不同，通过直接测量细胞质量消除了底物浓度和氧气浓度变化对观察到的细胞质量信号的影响。该传感器坚固耐用，能够经受多次原位蒸汽灭菌循环而不降解，并且其荧光信号与本研究中所有研究物种的浓度呈线性关系。结果表明，酵母中的色氨酸荧光比NADH荧光更能准确测量细胞质量。
