Pseudomonas fragi CRDA 037 produced extracellular (exo-) and intracellular (endo-) lipases when grown in whey media. Partially purified lipase extracts were obtained by precipitation with solid ammonium sulphate at 20-40% saturation for the exolipase and 20-60% saturation for the endolipase. Native polyacrylamide gel electrophoresis of the exolipase showed the presence of a major band with a molecular weight (M(r)) of 25.5 kDa, whereas the endolipase showed the presence of three fractions with M(r) of 35.5, 49 and 70 kDa. The pH optima for the exo- and endolipases were 8.75 and 9.0, respectively. Substrate specificity determinations were performed with triacetin, tributyrin, trimyristin and triolein, where exo- and endolipase demonstrated higher affinity for trimyristin, with K-m values of 5.11 and 3.24 mM, respectively. Inhibition of the exo- and endolipase occurred in the presence of a range of chemicals, including sodium deoxycholate, ferrous and ferric chloride, diisopropyl fluorophosphate, N-bromosuccinimide and 5,5-dithiobis-(-2-nitrobenzoic acid).