The hydrolysis of trehalose is confined in yeasts to the enzyme trehalase.

Two kinds of trehalase exist in yeasts: neutral (cytosolic) and acid (vacuolar or cell wall-linked) activities.

Both trehalases differ in biochemical parameters, physiological roles, regulatory mechanisms and tridimensional structure.

The yeasts trehalases share identical substrate specificity for trehalose.

The structure of the active centre and the catalytic mechanism are similar in neutral and acid trehalases.