24. This is dependent on the devices used, the scale (how big an

impact in terms of culture volume the sampling might have),

and sampling frequency. In particular for low volume bioreac-

tors, the loss of volume due to sampling can have an impact on

overall performance.

25. Mainly two feeding modes are used: Continuous feeding,

which means constantly adding a small amount of feed

(s) once the feed addition has been initiated using a low flow

pump (this is usually performed using a connected scale to be

able to control the amount added in 24 h). Alternatively, the

feeds are added in bolus mode, meaning that feeds are added at

a pre-defined interval (usually once per day once the feed

addition has been initiated) as a short burst. This requires less

automation as the pump could be activated by hand and

stopped when the target weight is reached. Continuous feed-

ing is smoother for the culture but requires more infrastructure

to be precise. Importantly, it is generally not possible to test

this approach in a less automated format like shake flask.

26. Addition of antifoam once to completely remove the foam is

more efficient than putting multiple small doses. If foam is not

controlled, clogging of the filter could occur.

Acknowledgments

We would like to thank David Hacker for his input and support in

writing this chapter and Eppendorf AG for providing images used

in the creation of the figures.

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