Vasala Antti, Panula Johanna, Bollók Monika, Illmann Lutz, Hälsig Christian, Neubauer Peter
Bioprocess Engineering Laboratory, Department of Process and Environmental Engineering and Biocenter Oulu, University of Oulu, Oulu, Finland.
Microb Cell Fact. 2006 Feb 24;5:8. doi: 10.1186/1475-2859-5-8.
Shake flasks are widely used because of their low price and simple handling. Many researcher are, however, not aware of the physiological consequences of oxygen limitation and substrate overflow metabolism that occur in shake flasks. Availability of a wireless measuring system brings the possibilities for quality control and design of cultivation conditions.
Here we present a new wireless solution for the measurement of pH and oxygen from shake flasks with standard sensors, which allows data transmission over a distance of more than 100 metres in laboratory environments. This new system was applied to monitoring of cultivation conditions in shake flasks. The at-time monitoring of the growth conditions became possible by simple means. Here we demonstrate that with typical protocols E. coli shake flask cultures run into severe oxygen limitation and the medium is strongly acidified. Additionally the strength of the new system is demonstrated by continuous monitoring of the oxygen level in methanol-fed Pichia pastoris shake flask cultures, which allows the optimisation of substrate feeding for preventing starvation or methanol overfeed. 40 % higher cell density was obtained by preventing starvation phases which occur in standard shake flask protocols by adding methanol when the respiration activity decreased in the cultures.
The here introduced wireless system can read parallel sensor data over long distances from shake flasks that are under vigorous shaking in cultivation rooms or closed incubators. The presented technology allows centralised monitoring of decentralised targets. It is useful for the monitoring of pH and dissolved oxygen in shake flask cultures. It is not limited to standard sensors, but can be easily adopted to new types of sensors and measurement places (e.g., new sensor points in large-scale bioreactors).
摇瓶因其价格低廉且操作简单而被广泛使用。然而，许多研究人员并未意识到摇瓶中发生的氧气限制和底物溢流代谢的生理后果。无线测量系统的出现为培养条件的质量控制和设计带来了可能性。
在此，我们展示了一种新的无线解决方案，用于使用标准传感器测量摇瓶中的pH值和氧气含量，该方案能够在实验室环境中实现超过100米距离的数据传输。这个新系统被应用于监测摇瓶中的培养条件。通过简单的方式就可以实现对生长条件的实时监测。我们在此证明，按照典型方案进行的大肠杆菌摇瓶培养会遭遇严重的氧气限制，并且培养基会强烈酸化。此外，通过持续监测甲醇喂养的毕赤酵母摇瓶培养中的氧气水平，展示了新系统的优势，这使得能够优化底物添加量，以防止饥饿或甲醇过量添加。通过在培养物呼吸活性下降时添加甲醇来防止标准摇瓶方案中出现的饥饿阶段，细胞密度提高了40%。
本文介绍的无线系统能够在培养室或封闭培养箱中剧烈摇晃的摇瓶上远距离并行读取传感器数据。所展示的技术允许对分散的目标进行集中监测。它对于监测摇瓶培养中的pH值和溶解氧很有用。它不仅限于标准传感器，还可以轻松应用于新型传感器和测量场所（例如，大型生物反应器中的新传感器点）。
