Problem: The utilization of suboptimal inoculum can severely worsen the bioprocess outcome.
Monitoring and analysis of inoculum characteristics at the seed fermenter stage are well established in most bioprocesses. However, the very first steps of culture expansion in shake flasks are usually neglected, even though they are influencing all following process steps. Inoculum must be in a healthy and active state and must be available in a sufficiently large volume at the planned inoculation time. It must also be in a suitable morphological state, free of contamination, and retain its product-forming capabilities.
Solution: We present an integrated approach for optimal inoculum preparation in shake flasks with automated inoculation, conditioning, and online monitoring.
The multi-step integrated inoculum preparation process involves: (1) preconditioning the seed inoculum at low temperatures, (2) controlling the harvesting time point with preprogrammed seed inoculation, (3) monitoring the cell growth in real-time to identify optimal harvesting times as well as potentially growing contaminations, and (4) harvesting time elongation based on multiple inoculation setups.