Integration and intensification of bioseparations : a role for pellicular solid phases in combinatorial cell disruption and fluidised bed adsorption

The development of a rapid and simplified primary capture step for the direct selective recovery of intracellular proteins from particulate-containing yeast disruptate in the circumvention of problems associated with conventional fluidised bed/expanded bed adsorption has been undertaken. A protoype pellicular adsorbent, designed for intensified fluidised bed adsorption processes, was assembled by the three-phase emulsification coating of porous agarose upon a zirconia-silica solid core. The adsorbent, designated ZSA, was subj ected to physical and biochemical comparison with the performance of two commercial adsorbents (Streamline and Macrosorb K4AX). Bed expansion qualities and hydrodynamic characteristics (N, Daxl and Bo) of ZSA demonstrated a marked robustness in the face of elevated velocities (up to 550 cm/h) and biomass loading (up to 30% ww/v) disrupted yeast cells. Cibracron Blue derivatives of the pellicular prototype (ZSA-CB), evaluated in the batch and fluidised bed recovery of glyceraldehyde 3-phosphate dehydrogenase (G3PDH) from unclarified yeast disruptates, exhibited superior capacities and adsortionldesorption performances to the commercial derivatives. These advanced physical and biochemical properties facilitated a demonstration of the direct coupling of bead-milling and fluidised bed adsorption in a fully integrated process for the accelerated recovery of G3PDH from yeast. The practical feasibility and generic applicability of the direct integration in the same time frame of cell disruption with the capture of intracellular products has been demonstrated. The application of a multi-fluidised bed system (MFBS), where each bed is sequentially operated on-line to the disrupter to achieve a repetitive operation of this cycle was proposed and studied. The generic application of such pellicular adsorbents and integrated processes to the recovery of labile, intracellular products has been assessed.