The increasing interest in manifactured enzymes introduces a new area of importance to applied rheologists. Both in the preparation and use of these novel materials rheology plays a major role and an understanding of how it affects production processes and product quality is extremely important. This paper deals with the harvesting of Glucose Isomerase. This is an enzyme used to convert glucose to fructose. Attention is focused on the extrusion forming step which shapes the flocculated cells into particles suitable for use in packed beds.