INFLUENCE OF SUBSTRATE OSCILLATIONS ON ACETATE FORMATION AND GROWTH-YIELD IN ESCHERICHIA-COLI GLUCOSE-LIMITED FED-BATCH CULTIVATIONS
INFLUENCE OF SUBSTRATE OSCILLATIONS ON ACETATE FORMATION AND GROWTH-YIELD IN ESCHERICHIA-COLI GLUCOSE-LIMITED FED-BATCH CULTIVATIONS
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DOI：
10.1002/bit.260470204
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发表时间：
1995-07-20
影响因子：
3.8
通讯作者：
ENFORS, SO
中科院分区：
文献类型：
--
作者：
NEUBAUER, P;HAGGSTROM, L;ENFORS, SO
大型生物反应器是具有浓度梯度的非均相系统，浓度梯度取决于反应器的流体动力学和传质、进料策略、饱和常数和细胞密度。在由搅拌槽反应器（STR）和充气活塞流反应器（PFR）组成的两室反应器系统中研究了大肠杆菌细胞对葡萄糖限制补料分批培养中碳/能量底物短期振荡的响应作为循环回路。短期葡萄糖过量或饥饿的PFR模拟葡萄糖饲料的PFR或STR交替。细胞对反复短期葡萄糖过量的反应是葡萄糖消耗和乙酸盐形成的短暂增加。但是，在培养物中没有乙酸盐的积累，因为它在葡萄糖浓度限制生长的STR部分被消耗。然而，如果PFR中的氧气供应不足，则乙酸盐在培养期间积累，导致更高的乙酸盐形成。生物质产量则受到负面影响，如果PFR用于模拟葡萄糖饥饿区，情况也是如此。结果表明，短期的异质性影响细胞的生理和生长，并可能是非常重要的工艺性能。(C)1995年，John Wiley and Sons，Inc.
A large bioreactor is an inhomogenous system with concentration gradients which depend on the fluid dynamics and the mass transfer of the reactor, the feeding strategy, the saturation constant, and the cell density. The responses of Escherichia coli cells to short-term oscillations of the carbon/energy substrate in glucose limited fed-batch cultivations were studied in a two-compartment reactor system consisting of a stirred tank reactor (STR) and an aerated plug flow reactor (PFR) as a recycle loop. Short-term glucose excess or starvation in the PFR was simulated by feeding of glucose to the PFR or to the STR alternatively. The cellular response to repeated short-term glucose excess was a transient increase of glucose consumption and acetate formation. But, there was no accumulation of acetate in the culture, because it was consumed in the STR part where the glucose concentration was growth limiting. However, acetate accumulated during the cultivation if the oxygen supply in the PFR was insufficient, causing higher acetate formation. The biomass yield was then negatively influenced, which was also the case if the PFR was used to simulate a glucose starvation zone. The results suggest that short-term heterogeneities influence the cellular physiology and growth, and can be of major importance for the process performance. (C) 1995 John Wiley and Sons, Inc.