A comparison of Escherichia coli fermentations run in the ambr®250 and 100L stainless steel vessels: confirming scalability for process development

Upstream development of fermentation processes for cGMP manufacture can be an expensive, time-consuming and complicated process, requiring high levels of process understanding in order to meet regulatory demands.  Recent advances in high throughput technology such as the ambr^®250 can help, for instance by enabling rapid screening of multiple parameters and incorporation of Quality by Design principles early on in the development process.  However, it is important to ensure that such systems are scalable, thus confirming the suitability of the processes being developed for larger scale manufacturing equipment.  FUJIFILM Diosynth Biotechnologies have successfully demonstrated such scalability, developing an Escherichia coli process for intracellular product expression using their proprietary pAVEway^TM expression system and the ambr^®250, showing comparability with conventional stainless steel vessels up to 100L scale.  Applying a fed-batch process and using defined media, process performance was assessed between ambr^®250 250mL and Sartorius Stedim BioStat D20 (20L) and D100 (100L) stainless steel vessels.  Control of fermentation parameters, e.g. pO₂, pH and temperature, was comparable, as were process timings such as glycerol depletion and IPTG induction.  Off-gas analysis gave similar profiles for oxygen uptake and carbon dioxide evolution rates and off-line measurements of biomass  and corresponding growth profiles were also aligned.  In conclusion, the ambr^®250 was shown to be a good scale-down model for conventional bioreactors, with processes developed at 250mL scale and using high throughput technology representative of performance at larger scales, thus reducing development timelines and resource requirements, whilst still providing well characterised, robust and scalable fermentation processes.