I think you're describing the field of [bioprocess engineering](https://en.wikipedia.org/wiki/Bioprocess_engineering https://en.wikipedia.org/wiki/Bioprocess_en

I think you're describing the field of [bioprocess engineering](https://en.wikipedia.org/wiki/Bioprocess_engineering https://en.wikipedia.org/wiki/Bioprocess_engineering). A lot of time is spent trying to balance cell growth with the possibility of mutations being introduced into the system. Even between different strains of E. coli the doubling rate can vary. Moreover, one also needs to contend with the fact that prokaryotes typically cannot produce very complex proteins. This leads some processes to need to use eukaryotes such as CHO cells, which are much slower.