High-throughput determination of volumetric oxygen transfer coefficients (kLa) in microtiter plates using the BioLector system

Characterization of cultivation parameters at screening scale is essential for transfer to production systems, particularly with respect to gas transfer efficiency, expressed as the volumetric oxygen transfer coefficient (k$_L$a). In this work, the O$_2$ downregulation mode of the commercially available high-throughput screening platform BioLector was repurposed and shown to be suitable for determining k$_L$a using the physical gassing-out method. As an example, the influence of liquid filling volume in microtiter plates, shaking frequency and aeration rate on k$_L$a was investigated, resulting in values of up to 6 h$^{-1}$ under the tested conditions. Overall, this semi-automated approach allows kLa characterization with little manual effort and supports process transfer between cultivation systems by enabling oxygen transfer conditions in BioLector experiments to be considered during scale translation.