EN
Trehalase activity (THA) was identified in the cell-free extracts of various organs of Medicago sativa: roots, roots nodules, stems and leaves, as well as in seediings and seeds. It showed the high activity at acid pH and optimal temperature ranged from 45 ℃ to 55 °C. It was also differently affected by ions, i.e. the presence of calcium stimulated this activity but it was inhibited by Zn2+ and NH4+. After separation by DEAE-cellulose chromatography and purification procedures, trehalase from alfalfa was purified 800 times, and Superose 12 HR gel filtration allowed to determine the molecular weight of 120 kDa for the native enzyme from the stems of alfalfa.