A novel multiparameter sensor for shake flask cultivations: Online biomass, dissolved oxygen, and fluorescence monitoring for comprehensive bioprocess characterization

Shake flasks are one of the most widely used cultivation vessels in biotechnological process development. To improve the process understanding, new technologies have been reported for online monitoring of different parameters like oxygen, pH, or biomass in the last couple of years. However, most reports address the monitoring of a single parameter per shake flask. This work evaluates the ability to measure dissolved oxygen (DO), biomass, and fluorescence in parallel with a new Multiparameter Sensor (MPS). Therefore, abiotic tests for reproducibility, sensitivity, and accuracy were performed. In biological tests, different microbial systems were used to evaluate if a wide range of applications is feasible. This work demonstrates that three different parameters: DO, biomass, and fluorescence can be monitored online, in parallel, for various biological systems. The online data obtained provide crucial process knowledge, such as the start of intracellular product formation. Abiotic and biological tests showed good reproducibility, resolution, and sensitivity to changing environmental conditions. Compared to other existing measurement systems for DO or oxygen transfer rate, similar or in the former case, more data points can be recorded, allowing a detailed overview and a better understanding of the process.