Glutaryl-7-ACA acylase was partially purified from the cellular lysate of Pseudomonas sp. NCIMB 40409 by means of reverse micelles-water-two-phases extractions. The tetrameric enzyme can be solubilized inside the reverse micelles formed by anionic (Aerosol OT, AOT) and cationic (tetradecyltrimethylammoniumbromide, TDAB) surfactants with retention of the enzymatic activity. With TDAB reverse micelles system, the acylase was partially extracted from the aqueous phase and, after backward transfer into a second water phase, a twofold purification factor was achieved. On the other hand, with the AOT micellar system, in conditions were most of the proteins but acylase, were extracted by the organic micellar solution, a sixfold increase of the specific activity of the acylase remaining in the aqueous phase was obtained.