nutritional medium requirement for chitinase production by Alcaligenes xylosoxydans IMI no. 385022 was optimized. The important medium components, identified by initial screening method of Plackett-Burman were Tween 20, yeast extract and chitin. Box-Behnken response surface methodology was applied to further optimize chitinase production. The optimal concentration for higher production of chitinase were (g/l): (NH4)(2)SO4, 1.0; KH2PO4, 1.36; MgSO4.7H(2)O, 0.3; Tween 20, 0.12; yeast extract, 0.3 and chitin, 15. Using this statistical optimization method, the chitinase production was found to increase from 12 to 29 U/ml. (C) 2003 Elsevier Science Inc. All rights reserved.