BACKGROUND: The investigation of enzymes from extremophilic microorganisms has generated great scientific interest in recent decades owing to their ability to operate in harsh conditions. Since lipolytic enzymes are one of the three groups most commercially demanded, the study of novel thermostable lipolytic enzymes is of much interest. RESULTS: Lipolytic enzymes produced by Thermus aquaticus YT1 have been investigated. Very interesting properties against thermal inactivation, with a half-life time of 1 h at 95 degrees C were found. The use of compounds such as polyols is a strategy used to further improve the thermostability of these enzymes, and the modelling of the deactivation process with a series-type equation, allows one to quantitatively ascertain the free energy of deactivation. Finally, the application to dibutyl adipate hydrolysis was investigated, as an indicator of the potential usefulness of the enzymes in polymer biodegradation. CONCLUSION: The crude lipolytic enzymes possess outstanding properties of thermostability (high lipolytic activity after 12 days at 80 degrees C, and a half-life time of 1 h at 95 degrees C), and they can be significantly improved by adding polyols (addition of glycerol entailed activity losses of just 3% after 1 h at 95 degrees C). These enzymes are able to catalyze ester cleavage, showing a zero-order kinetics. (C) 2011 Society of Chemical Industry