S95: High throughput screening and advanced bioprocess monitoring – tools for efficient process development and comprehensive system understanding

Today small scale screening platforms make an important contribution to efficient bioprocess development. However, for their application the results obtained during the early screening stage, e.g. selection of suitable production hosts and cultivation conditions, need to be transferable to a larger scale. To face these challenges we use the BioLector micro fermentation system (m2p-labs) which enables high throughput microtiter plate cultivation with real time monitoring of the important process parameters biomass concentration, pH value and dissolved oxygen. By using media based on enzymatic glucose release, we have developed stable protocols for carbon limited cultivation of recombinant Escherichia coli strains in the BioLector, under conditions similar to standard fed batch production processes.

In the succeeding characterization of the large scale bioprocess the major challenges are the complexity of biological systems and the limited capabilities of in situ and real-time monitoring. For comprehensive process and host system characterization in the bioreactor, we have established a process monitoring platform were two different approaches are followed. 1.) By acquisition of nonspecific signals and spectra indirectly related to the cell-population and media compounds and by extraction of the cell physiological relevant information we are able to ‘online monitor’ complex variables such as cell density or product titer. 2.) By detection of volatile organic compounds (VOCs) via headspace sampling in a proton transfer reaction-mass spectrometry (PTR-MS) we are enabled to directly and non-invasively determine important metabolites.

The established screening and process monitoring platform allows us to perform efficient process development and rational process and host design.