FRUCTAN-HYDROLYZING ACTIVITIES FROM LOLIUM-RIGIDUM GAUDIN

Fructan- and sucrose-hydrolyzing activity was extracted from plants of Lolium rigidum Gaudin. Sucrose-hydrolyzing activity varied 30-fold between different plant parts and parts of different ages. In contrast, fructan-hydrolyzing activity only varied two-fold. At least four beta-fructofuranosidase activities were partially purified from mature vegetative tissues of Lolium rigidum. The beta-fructofuranosidases were characterized by their different elution patterns on various chromatographic media and their relative rates of hydrolysis of sucrose and fructan extracted from different sources. Fructan-hydrolyzing activities were partially purified that hydrolyzed fructan containing predominantly 2-1 glycosidic linkages relatively more rapidly than fructan containing predominantly 2-6 glycosidic linkages. beta-fructofuranosidases that were relatively more active against fructan than sucrose when compared with activity present in the crude extract, were inhibited by sucrose. It is concluded that it is necessary to use appropriate fructan substrates and to consider the possible involvement of all beta-fructofuranosidase activities in hydrolysis of fructans in grasses.