AN APPROACH TO INTEGRATED ANTIBODY-PRODUCTION - COUPLING OF FLUIDIZED-BED CULTIVATION AND FLUIDIZED-BED ADSORPTION

Continuous culture may be an efficient way of producing proteins which are susceptible to secondary processing in the course of a fermentati on process. Short residence times in these systems support the product ion of correctly assembled proteins by avoiding substrate limitations and product inhibitions and also minimize the contact of sensitive bio products with degrading enzymes. Thus products of increased stability and integrity are obtained from continuous processes. The downstream p rocess following continuous culture has to be adapted to the specific conditions of continuous fermentations, e.g. large liquid volumes and diluted process solutions. In this paper an approach is shown how a fl uidized bed adsorption as first recovery operation may be coupled dire ctly to a continuous production. Immobilized hybridoma cells are culti vated in porous glass microcarriers in a continuous fluidized bed proc ess, the cell containing harvest is purified by fluidized bed adsorpti on using an agarose based cation exchange matrix. By this coupled mode of operation the large biomass containing harvest volume resulting fr om the continuous cultivation may be applied directly to a fluidized c hromatographic matrix without prior clarification, leading to a partic le free and initially purified product solution of reduced volume. In an experimental setup a bench-scale fluidized bed bioreactor of 25 mi carrier volume was coupled to a fluidized bed adsorption column operat ed with 300 mi of adsorbent. This configuration yielded up to 20 mg of monoclonal antibody per day in a cell free solution at fourfold conce ntration and fivefold purification. The process was run for more than three weeks with consistent product output.