Inulinase was produced by Aspergillus niger van Teighem UV11 in a 10 l glass fermenter using readily-available nitrogenous by-products, corn steep liquor (CSL), defatted groundnut meal and defatted soyabean meal, in different ent concentrations with kuth (Saussurea lappa) root powder as a source of inulin (as inducer), under varying agitation conditions. With the combination of kuth (1.0%), aeration (1.5 vvm) and agitation (300 rpm), the maximum yield of insulinase obtained was 290 Uml(-1) after 72 h.