Particle and Cell Separations in Bioprocessing

This session examines the performance and development of physical separations to remove parental biomass from liquid solutions containing biochemical products in crude or intermediate form. Biomass suspensions can derive from fermentation of cells of plants or mammals or from solvent extraction of transgenic plants. Bioprocessing aims to remove solid-phase cells, growth media, bacteria and other contaminating particulates that would interfere with subsequent purification of the product. Some form of filtration or sedimentation dominates the means and efficient separation can require two stages where the solids span several orders of magnitude in size or their concentration is high. Primary solids are removed by centrifugal sedimentation or cake filtration driven by pressure, vacuum or centrifugal force. The resulting liquid is clarified or polished by pressure-driven membrane microfiltration, cartridge filtration, depth filtration including the use of filter aids, or centrifugal sedimentation at high g-force. Biomass is frequently washed with solvent to further recover valuable solutes by displacement or repeated dissolution (reslurry). Topics of interest include all these various technologies applied in bioprocessing.