The effects of submerged cultivation parameters on the production of chitinase by Verticillium lecanii in a shaker-flask and bioreactors were investigated. The activity of chitinase was 9.95 mU/ml in an optimal culture medium with culture volume at 200 ml, agitation rate at 150 rpm, and 24degreesC in shaker-flask cultivation. Based on this result, the scale-up cultivation with a 5-1 stirred-tank bioreactor (STR) and a 30-1 airlift bioreactor were conducted. The high chitinase activity 18.2 mU/ml was obtained under the optimal cultivation conditions of aeration rate at 0.6 vvm, pH 4, agitation rate at 150 rpm, and 24degreesC, with a 5-1 STR. The chitinase went up to 19.9 mU/ml by using 30-1 airlift bioreactor with 24-mesh net-draft tube at aeration rate of 0.9 vvm, pH 4, and 24degreesC. The study revealed that the pH and agitation rate were the most significant factors for the effects on chitinase production. Nevertheless, agitation rate and aeration rate could affect dissolved oxygen (DO) concentration that in turn affected V lecanii growth and chitinase production. (C) 2003 Elsevier Inc. All rights reserved.