IPTG limitation avoids metabolic burden and acetic acid accumulation in induced fed-batch cultures of Escherichia coli M15 under glucose limiting conditions
IPTG limitation avoids metabolic burden and acetic acid accumulation in induced fed-batch cultures of Escherichia coli M15 under glucose limiting conditions
复制标题
DOI：
10.1016/j.bej.2012.10.006
复制
发表时间：
2013-01-15
影响因子：
3.9
通讯作者：
Cairo, Jordi J.
中科院分区：
文献类型：
--
作者：
Lecina, Marti;Sarro, Enric;Cairo, Jordi J.
使用大肠杆菌作为表达载体生产重组蛋白的最常见策略是补料分批培养，因为高细胞密度培养策略已成功应用。几种控制比生长速率的方法。大肠杆菌的代谢已经被定义，证明培养物可以在葡萄糖限制下生长到高细胞密度而不积累乙酸。然而，在诱导条件下，已经观察到E.大肠杆菌代谢重组导致乙酸积累，抑制细胞生长，降低蛋白表达效率。大肠杆菌补料分批培养，以避免在诱导阶段代谢的失调。降低IPTG浓度，保持葡萄糖生长限制，乙酸积累减少。在0.03 mmol/g DCW的IPTG浓度下，在诱导阶段没有观察到乙酸的积累，与通常观察到的相反，虽然在应用这种双重限制策略时观察到蛋白质表达率略有降低，但由于能够延长诱导阶段，生物过程的体积生产率得到提高，达到更高的蛋白质生产水平。该策略的另一个优点是由于使用的IPTG水平较低而降低了培养基成本。(C)2012爱思唯尔有限公司版权所有。
The most common strategy to produce recombinant proteins using Escherichia coli as expression vector is fed-batch culture, since high cell density cultures strategies have successfully been applied. Several methodologies to limit the specific growth rate in order to control E. coli metabolism have been defined, demonstrating that cultures can be grown under glucose limitation up to high cell densities without accumulation of acetic acid. However, under induction conditions it has been observed that E. coli metabolism is reorganized again and leads to acetic acid accumulation, causing inhibition of cell growth and decreasing protein expression efficiency.We propose a double limitation strategy (glucose and IPTG) for E. coli fed-batch cultures to avoid the deregulation of the metabolism in the induction phase. Reducing the concentration of IPTG while keeping glucose growth limitation, the accumulation of acetic acid decreased. At an IPTG concentration of 0.03 mmol/g DCW no accumulation of acetic acid was observed during the induction phase, in contraposition to what has normally been observed.Although a slight reduction of protein expression rate was observed when applying this double limitation strategy, the bioprocess volumetric productivity was enhanced due to the capability to prolong the induction phase, reaching higher levels of protein production. Another advantage of this strategy is the reduction of media cost due to the lower level of IPTG used. (C) 2012 Elsevier B.V. All rights reserved.