Abstract: Trehalose is a natural functional d isaccharide.It could be widely used in foodstuffs,pharmaceuticals,cosmeticandagricultureproducts.Trehalose’ s useswererestrictedduetothediff icultyinproducingit.Recently,peoplefoundanovelenzymefrombacteria---trehalosesynthase.This studymain lydiscussedthecharacteristics of trehalose synthase activity in permeabilized cells.The properties o f trehalose synthase in the permeate d cells were investigated systematically.The enzyme exhibited an optimumtemp erature of 35℃,and an optimumpHof7.0～7.8.The enzyme was stable at30～40℃,pH6.6～7.8.The activity of treh alose synthase was increased by addition of Mg 2+ ,K + and Na + ,but was inhibited by Zn 2+ ,Mn 2+ ,Cu 2+ ,Ca 2+ ,Ba 2+ .The enzyme could cat-alyze the conversion ofmaltose into trehalose by intramolecular transg lucosylation,but it could slightly hydrolyze maltose into glucose,and it was inactive on other saccharieds.

Key words: trehalose synthase, characteriza tion of the enzyme, permeabilized cells