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Reproducible processes for fermentation

Individual gas control systems for fermenters - cooperation with ZETA

Benefit from a certified complete system:

  • Easy integration: MFCs and necessary components can be combined to form a ready-to-connect, certified gas control system.
  • Certified ingredients: All wetted parts are made of stainless steel; the MFCs conform to USP Class VI, 21CFR177 and are available with certificate 3.1 according to DIN EN 10204.
  • Flexible gas supply: The MFCs can be calibrated for up to four different gases, which are then fed into the process.
  • From a single source: Procurement process via one supplier, including complete system documentation.

With fermentation processes, precise control of the gas quantities is crucial for the quality of the product. Only when bacteria or other biological materials get the right food can they thrive. The gas quantities must be adapted to the needs of the constantly propagating cultures. This process must be controlled precisely and reproducibly. The gas dosing data should also be reproducible and retrievable at any time, and it should be possible to document it. Mass flow controllers (MFC) that can be calibrated to several different gases open up interesting possibilities. They can be combined with all the necessary components to form ready-to-connect gas control systems (gas box) and can then be easily integrated into the fermenters as a complete system.


Gasregelsystem für Fermenter

The ready-to-connect, complete gas control system requires about half as much installation space as previous solutions.

Flexible fermenters for the industry

The ZETA group of companies, with it headquarters in Austria near Graz, is a specialist for customised process and procedural solutions for fermentation plants. As a technology supplier to the biotechnology and pharmaceutical industries, ZETA designs, manufactures, installs and digitises customised solutions for renowned companies around the world. One example of this is flexible fermenters that can be used for many applications thanks to different gassing processes. The reproducibility of the individual fermentation processes is guaranteed by automation solutions adapted to the application, standard CIP/SIP runs and defined control strategies. ZETA uses MFCs from Bürkert to control gases required in fermentation such as air, oxygen, nitrogen or carbon dioxide. 

“It was very important for us to obtain a highly flexible and at the same time compact gas system that also meets all current requirements for the certification of the materials in contact with the media. These are in particular the solenoid valves, which in addition to the 3.1 certificate are also certified to USP Class VI and 21CFR177, as well as the valve block.”

Florian Stolka, Senior Project Engineer at ZETA

From single components to individual gas control systems


The MFCs are designed as compact devices incorporating the following components: flow sensor, control electronics as well as a proportional valve as an actuator. The thermal MEMS sensor is located directly in the gas flow and achieves very fast response times and the highest level of measuring accuracy, with long-term stable calibration. The devices guarantee very sensitive and precise control, independent of disturbance variables such as pressure fluctuations or temporary flow resistances. All wetted parts are made of stainless steel and the MFCs conform to USP Class VI, 21CFR177 and are available with certificate 3.1 according to DIN EN 10204. At the fermenters, the MFCs are not lone fighters. They can be calibrated to up to four different gases, which are then made available to the process as required. For this purpose, three solenoid valves are positioned after each MFC to direct the gases to the desired connection points on the fermenter. This provides maximum flexibility in the gas supply to the respective organism. It can be dynamically adapted to the process requirements via the formulation.




All from one source: components, control cabinet construction and engineering

“For us, the cooperation has been worthwhile. The complete solution from a single source has significantly reduced our procurement effort and allows us to focus on our core competencies”.

Florian Stolka, Senior Project Engineer at ZETA

The gas control system, which is contained in a housing accessible from the front, consists of four to six MFCs, each with three certified solenoid valves for the different gases and the required check valves, depending on the area of application and the required gas flows. To suit the applications (e.g. laboratory, production) and to avoid unnecessary costs, the individual gas control system is also supplied in two different levels of certification. For fermenters in production plants in the pharmaceutical or biochemical industry, the gas lines must also meet the highest requirements in terms of the biocompatibility of the materials used and components that come into contact with the media. Another advantage is the simple procurement process of the complete gas box system from one supplier. You get the complete system documentation including all certificates from one source.


Simple start-up thanks to ready-to-connect delivery

Gasregelsysteme für Fermenter

“Again, the fluidics experts responded competently and to our complete satisfaction.”

Sebastian Wagner, Project Engineer at ZETA

On site, the plant engineers only have to connect the power and media supply. All in all, the development of the individual gas control systems for the fermenters went smoothly. However, as with any process, there were one or two challenges to overcome. For example, Bürkert's own CANopen-based bus system was adapted to the control of the fermenters. The MFCs now communicate with the higher-level controller via Profinet. The check valves used were also modified for use in gas control systems, as it was found in operation that these valves caused vibrations on the MFCs, which impaired the control performance. The solution: the spring of the check valves was removed, the function was maintained and the cause of the vibrations was eliminated.




“In Bürkert we found a competent partner for the development of this gas box. In close, collegial cooperation, a ready-to-connect, complete gas control system was developed that is precisely tailored to our requirements, and only takes up about half as much installation space as previous solutions.”

Florian Stolka, Senior Project Engineer at ZETA