Yegneswaran P K, Gray M R, Thompson B G
Department of Chemical Engineering, University of Alberta, Edmonton, Canada.
Biotechnol Prog. 1991 May-Jun;7(3):246-50. doi: 10.1021/bp00009a008.
A proportional-integral control system was used to control dissolved oxygen in a fermentor at constant shear and mass transfer conditions. Growth and antibiotic production in Streptomyces clavuligerus were studied at different dissolved oxygen levels during the fermentation. Three protocols were employed: no-oxygen control to provide a base case, oxygen controlled to a preset saturation level throughout the fermentation, and oxygen controlled at a high level only during the growth phase. The last protocol was aimed at optimizing the consumption of oxygen. Lower specific growth rates and cephamycin C yields were obtained when dissolved oxygen was controlled at 50% throughout the fermentation, compared to the base case. A 2.4-fold increase in the final cephamycin yield was observed when dissolved oxygen was controlled at saturation levels during the growth phase, compared to the experiments without dissolved oxygen control. This enhancement in yield was independent of the dissolved oxygen (DO) level after exponential growth, in the range of 50-100% saturation. The most effective control strategy, therefore, was to control DO only during active growth when the biosynthetic enzymes were probably synthesized.
在恒定剪切和传质条件下，采用比例积分控制系统来控制发酵罐中的溶解氧。研究了棒状链霉菌在发酵过程中不同溶解氧水平下的生长和抗生素生产情况。采用了三种方案：无氧控制作为基础情况，在整个发酵过程中将氧气控制在预设的饱和水平，以及仅在生长阶段将氧气控制在高水平。最后一种方案旨在优化氧气消耗。与基础情况相比，在整个发酵过程中将溶解氧控制在50%时，比生长速率和头孢霉素C产量较低。与无溶解氧控制的实验相比，在生长阶段将溶解氧控制在饱和水平时，最终头孢霉素产量提高了2.4倍。在指数生长后，溶解氧水平在50%-100%饱和范围内时，产量的提高与溶解氧（DO）水平无关。因此，最有效的控制策略是仅在可能合成生物合成酶的活跃生长期间控制溶解氧。
