Lipase-catalyzed synthesis of isoamyl isobutyrate in dodecylbenzenesulfonic acid (DBSA)/isooctane microemulsion system was reported in this paper. The effects of such factors as water content (w₀), pH of buffer solution and temperature on the esterification were investigated. Compared with the former research in CTAB microemulsion system, the reaction rate of the esterification and the conversion in short time were all increased obviously in DBSA microemulsion system. The conversion of this reaction exceeded 90% after 9 h in mild condition. So it is a new microemulsion system and even suitable for the esterification. Through the contrast of DBSA system with lipase present and absent, it was concluded that DBSA, as a kind of proton acid, has catalytical ability to the esterification. The microemulsion catalyzed, enzyme catalyzed and proton acid catalyzed ternary mechanism was proposed in this microemulsion system.

Key words: DBSA, microemulsion, lipase, catalyzed-synthesis, isoamyl isobutyrate