(58q) Continuous Non Centrifugal Phase Separation in Biphasic Whole-Cell Biocatalysis Using a Lab-Scale Prototype

Biphasic whole-cell bio-processes have already reached levels of industrial relevance and are known to be efficient and green alternatives to common chemical synthesis routes. The main bottleneck for an industrial implementation of these high-potential (high stereo selectivity, high product titers) biphasic whole-cell bio-processes is the presence of particles (cells) resulting in the formation of stable Pickering type emulsions hindering cost-efficient and effective DSP.

In contrast to state of the art DSP-processes e.g. centrifugation or the use of de-emulsifiers, the phenomenon of catastrophic phase inversion (CPI) applied within this work, easily achieves phase separation by addition of dispersed phase. Due to a sudden switch of emulsion type, Pickering type emulsions are destabilized efficiently and phase separation is achieved with minimal effort.

Based on a patent filed at TU Dortmund, a process concept (termed: Applied Catastrophic Phase Inversion; ACPI) was developed, enabling continuous phase separation of stable emulsion by using the CPI phenomenon. A fully automated pilot-scale prototype was planned and constructed. Various sensors e.g. for conductivity or level-control allow for process monitoring and control. First runs were performed for defining a process window (necessary amount of disperse phase, flow and mixing rates, settler setup, etc.). In further runs also the stability of the process was evaluated by introducing external disturbances. Especially the influence of varying O/W ratios in the feed emulsion) were analyzed. All results will be presented, demonstrating the efficiency and applicability of the concept for phase separation of stable Pickering type emulsions.

ACPI benefits from its simple setup, low operating costs, a broad applicability irrespective of product concentration and success of the initial biotransformation. This fact qualifies ACPI as a considerable alternative as first separation step in the DSP of biphasic whole-cell biotransformations.