A Fusarium solani pisi recombinant cutinase solubilized in phosphatidylcholine/isooctane reversed micellas was used to catalyse the esterification reaction of butyric acid with 2-butanol at pH 10.7. The influence of temperature, Wo and substrates on lipase stability was evaluated. The enzyme displays a better stability, with a half-life over 125 days, at a temperature of 22 degrees C and for a low water content (W-O=6.5). Butyric acid increased the cutinase deactivation (t(1/2)=0.56h), while 2-butanol led to a similar half-life (t(1/2)=14h) as without substrate.