Hansen Sven, Gumprecht Andreas, Micheel Linda, Hennemann Hans-Georg, Enzmann Franziska, Blümke Wilfried
Evonik Operations GmbH, Marl, Germany.
Evonik Operations GmbH, Hanau-Wolfgang, Germany.
Front Bioeng Biotechnol. 2022 May 12;10:894295. doi: 10.3389/fbioe.2022.894295. eCollection 2022.
Since their first use in the 1930s, shake flasks have been a widely used bioreactor type for screening and process development due to a number of advantages. However, the limited gas-liquid mass transfer capacities-resulting from practical operation limits regarding shaking frequency and filling volumes-are a major drawback. The common way to increase the gas-liquid mass transfer in shake flasks with the implementation of baffles is generally not recommended as it comes along with several severe disadvantages. Thus, a new design principle for shaken bioreactors that aims for improving the gas-liquid mass transfer without losing the positive characteristics of unbaffled shake flasks is introduced. The flasks consist of cylindrical glass vessels with implemented perforated concentric ring walls. The ring walls improve the gas-liquid mass transfer the formation of additional liquid films on both of its sides, whereas the perforations allow for mixing between the compartments. Sulfite oxidation experiments revealed over 200% higher maximum oxygen transfer capacities (OTR) compared to conventional shake flasks. In batch cultivations of BL21 in mineral media, unlimited growth until glucose depletion and oxygen transfer rates (OTR) of up to 138 mmol/L/h instead of an oxygen limitation at 57 mmol/L/h as in normal shake flasks under comparable conditions could be achieved. Even overflow metabolism could be prevented due to sufficient oxygen supply without the use of unconventional shaking conditions or oxygen enrichment. Therefore, we believe that the new perforated ring flask principle has a high potential to considerably improve biotechnological screening and process development steps.
自20世纪30年代首次使用以来，摇瓶由于诸多优点，一直是用于筛选和工艺开发的广泛使用的生物反应器类型。然而，由于摇瓶的振荡频率和填充体积等实际操作限制导致气液传质能力有限，这是一个主要缺点。通常不建议通过设置挡板来增加摇瓶中气液传质的常用方法，因为它伴随着几个严重的缺点。因此，引入了一种用于振荡生物反应器的新设计原理，旨在在不丧失无挡板摇瓶的积极特性的情况下改善气液传质。这些摇瓶由带有穿孔同心环壁的圆柱形玻璃容器组成。环壁通过在其两侧形成额外的液膜来改善气液传质，而穿孔允许隔室之间的混合。亚硫酸盐氧化实验表明，与传统摇瓶相比，最大氧传递容量（OTR）提高了200%以上。在矿物培养基中对BL21进行分批培养时，在可比条件下，可以实现直至葡萄糖耗尽的无限制生长，氧传递速率（OTR）高达138 mmol/L/h，而不是像普通摇瓶那样在57 mmol/L/h时出现氧限制。甚至由于充足的氧气供应，无需使用非常规振荡条件或富氧，也可以防止溢流代谢。因此，我们认为新的穿孔环瓶原理具有极大改善生物技术筛选和工艺开发步骤的潜力。
