A non-commercial immobilized lipase preparation from Staphylococcus simulans was used to catalyze the esterification reaction between acetic acid and isoamyl alcohol to synthetize isoamyl acetate (banana favour) in pure substrate conditions (without addition of any organic solvent). The effects of various reaction parameters such as the amount of lipase, the molar ratio of acetic acid as compared to isoamyl alcohol and the amount of initially added water were investigated. The optimum conditions for achieving 64% conversion during 8 It of incubation are 60 IU of immobilized lipase, an acid/alcohol of 2 molar ratio and an initial addition of water of 10% (w/w). No significant loss of the immobilized lipase activity was observed after four cycles of use of the immobilized enzymatic preparation. (c) 2005 Elsevier Inc. All rights reserved.