The use of an expanded bed of Streamline SP resin (Pharmacia) for the purification of an extracellular inulinase directly from an unclarified crude broth was investigated. The purification yield achieved 74% with a purification factor of about 10.4. Adsorption were similar whether the crude medium had microbial cells or not. The influence of bed expansion on adsorption performance was determined by frontal analysis. Breakthrough curves for inulinase were compared and the process was more efficient at a bed expansion degree of 2.0 (bed voidage of 0.7). (C) 2004 Elsevier Ltd. All rights reserved.