Bioreactors with ATF

Veenbrink RVS supplies bioreactors in various volumes. The bioreactors are characterised by a fermentation process within upstream biotechnology. This concerns a biological process in which micro-organisms are brought into an ideal environment. By very precisely controlling the conditions in the reactor, such as the pH value, temperature, pressure and oxygen content, the growth and activity of the micro-organisms are optimised. The cells ensure the production of nutrients for the final end product.

The life cycles of fermentation batches often have a uniform character. Cells that are exposed to the conditioned environment at the beginning of the process must first get used to the new environment. Once the cells are acclimated, they begin to double in a consistent manner. When the cells secrete to much waste, cell growth stagnates: the number of cells that die increases and the number of cells that double decreases. Harvesting takes place once the fermentation process is at its peak. Harvesting can be done in different ways:

• ISF (Internal Spin Filter) harvesting
• ATF (Alternating Tangential Flow) harvesting

With an ISF (Internal Spin Filter), the harvest is obtained by using a spin filter inside the reactor: a harvest tube collects all cell-free media that are in the spin filter. Because the filter has a certain mesh size, it ensures that cells remain outside the filter and the harvest zone and can continue to grow as long as the conditions are good.

However, with the ATF (Alternating Tangential Flow) of these bioreactors, the cell suspension (retentate) is removed from the bioreactor using vacuum techniques. Cell-free harvest is obtained and collected by pumping the suspension back into the bioreactor via the filter housing.