Abstract:To clone the alliinase gene from the garlic bulb and construct the eukaryote expression plasmid for expressing the recombinant alliinase in Pichia pastoris system and analyzing its bioactivity and antioxidant activity of alliin/alliinase mixture.The alliinase gene was cloned from the garlic bulb by RT-PCR and the eukary－ote expression plasmid of alliinase was constructed with the pPIC9k vector.The recombinant plasmid was transformed into Pichia pastoris GS115 by eletroporation.The positive clones were screened and were induced by methanol.Supernatants after induction were analyzed by SDS-PAGE.The activity of the recombinant protein was detected by the pyruvic acid method.Antioxidant activities of the alliin/alliinase mixture in vitro were analyzed by DPPH·in aerobic and anaerobic conditions respectively.The alliinase gene was successfully cloned from the garlic bulb，the recombinant alliinase existed in the supernatant of Pichia pastoris in the forming of glycoprotein.The specific activity of the recombinant protein was（115.81±1.93）U/mg.The total antioxidant capacity of alliin/alliinase mixture in anaerobic condition was higher than in aerobic condition.The alliinase gene is successfully expressed in Pichia pastoris system.alliin/alliinase mixture showed very good oxidation resistance is a very prospect for development with the material.