A new multisensory platform for bioprocess development of microbial cultures in shake flasks: engineering and applications

Although novel parallel cultivation technologies were developed shake flasks are still the work horse of microbial cultivation. A multisensory platform for shake flask cultivations with integrated sensors for online pO₂- , pH- and biomass monitoring was developed to study metabolic alterations during growth of bacteria and yeast. The biomass sensor can be used for a wide range of microorganisms like E. coli, L. zeae, P. pastoris, A. niger [1, 2].

The key feature of the biomass sensor is its superior sampling rate which delivers detailed information about the growth conditions that are not accessible by offline measurements. Small changes in the growth curve do indicate the exact time of limitations. Therefore, a fast response based on online biomass monitoring instead of time indifferent reaction on offline sampling is possible.

Another advantage is that combining all sensors in a compact system creates more confidence as they do complement each other. It was shown that oxygen and biomass measurement together offer a solid conclusion about the metabolic status of the culture. In addition, the multiple sensor concept offers higher flexibility in terms of choosing individually the appropriate sensor for each process or screening. In summary, multisensory monitoring enables to adjust the conditions in shake flask cultivations to be far more comparable to stirred bioreactors. Therefore, scale up with yield optimization can be performed more reproducibly.

[1] Schmidt-Hager, J. et al. Engineering in Life Sciences 2014, 14(5), 467-476

[2] Ude C. et al. Sensors 2014, 14, 17390-17405