Fructosyltransferase that catalyzes the polymerization of the fructose moiety of sucrose to produce inulin polymer and a broad range of inulin oligosaccharides ranging from DP2-DP13. Is also able to convert raffinose into a fructan polymer and fructo-oligosaccharides (FOS) in vitro; however, L.gasseri strain DSM 20604 is unable to ferment raffinose. Can also transfer fructose moieties of sucrose to maltose, leading to maltosylfructosides (MFOS). Also displays sucrose hydrolase activity. [(2->1)-beta-D-fructosyl](n) + sucrose = [(2->1)-beta-D-fructosyl](n+1) + D-glucose Calcium ions are required for optimal activity, but do not seem to be essential since addition of EDTA causes only a 30% drop in activity. Optimum pH is 3.5-4.5. Optimum temperature is 55 degrees Celsius. Activity drastically decreases at 60 degrees Celsius. Lacks the cell-wall-anchoring LPXTG/LPKAG motif found in protein orthologs, resulting in a partly free and partly cell-associated subcellular location status. Belongs to the glycosyl hydrolase 68 family.