The activity of three different lipases, a glycosidase and a protease in io
nic liquids has been studied. Ambient temperature ionic liquids are a new c
lass of solvents that are nonvolatile and nonflammable and thus an interest
ing alternative to classical organic solvents. Monitoring the synthesis of
a simple ester, all lipases were found to exhibit both excellent activity a
nd stability in the non-polar ionic liquid 1-butyl-3-methylimidazolium hexa
flurophosphate ([bmin][PF6], 1). Furthermore, beta -galactosidase from E. c
oli and the Subtilisin protease Savinase(TM) were both found to exhibit a h
ydrolytic activity in a 50% aqueous solution of the water-miscible ionic li
quid 1-butyl-3-methylimidazolium tetrafluoroborate ([bmin][BF4], 2) compara
ble to the activity observed in 50% aqueous solutions of ethanol and aceton
itrile.