Characterisation of esterase activities from the edible mushroom species, Amanita vaginata var. vaginata and Tricholoma terreum, were investigated. Native electrophoresis of the crude extracts prepared from both mushroom samples showed the presence of esterolytic activities. The extracts had the greatest activity in the presence of p-nitrophenyl butyrate (pNPB) as a substrate. pH and temperature optima were found to be 8.0 and 30 degrees C for both enzymes, respectively. V-max and K-m values were determined as 14.2 U/l and 71 mu M for A. vaginata var. vaginata and 34.6 U/l and 9.6 mu M for T. terreum, respectively. The pH-stability profile showed a stationary line between 3.0 and 10.0 for both enzymes. The esterolytic activities from the extracts were maintained between 10 and 40 degrees C for 4 h and started to decrease at 50 degrees C. The effects of EDTA, NaN3, DTT and PMSF on the enzyme activity were also investigated. (C) 2009 Elsevier Ltd. All rights reserved.