Exploration of Alternative Microfiltration Modalities for the Harvest and Clarification of Diverse Recombinant Proteins from High-Density E. coli Culture and Lysate using Hollow Fiber, Flat Sheet Cassette, and Vibro Membrane Filtration Technologies.

Abstract

Industrial bioprocess optimization has significantly increased the productivity of biomass and biologics in Upstream production. Such process improvement in fermentation often translates to challenges in recovering intracellularly expressed recombinant proteins due to increased matrix complexity, resulting in a higher performance burden in Midstream. Tangential flow filtration (TFF) is a popular industry standard for buffer exchange and protein separation from cellular debris. However, due to variations in the physicochemical properties of recombinant proteins, solutions for E. coli-based protein clarification remain challenging and often necessitate extensive exploration and process optimization. With growing options in filtration-based technologies, the identification of a near-universal clarification platform is desirable to accelerate bioprocess development overall. In this study, three TFF modalities, hollow fiber (HF), flat-sheet cassette (CAS), and vibro-membrane filtration (VMF), were assessed in parallel to evaluate their clarification performance for three E. coli recombinant proteins with different biochemical properties. Reverse phase liquid chromatography data showed target protein recovery was uniformly higher for VMF than HF at equivalent loading. Cell density and lysate protein load were comparable for HF and VMF, and lower for CAS. These results support the choice of VMF and HF as easily optimized and operated TFF modalities for clarification of recombinant protein from complex crude bacterial matrix, where either can be efficiently performed with ease and minimum supervision. Both TFF applications were successfully demonstrated in primary cell harvest, cell wash and cell lysate clarification, for E. coli-based recombinant proteins.