levan fructotransferase (DFA-IV-forming); 2,6-beta-D-fructan D-fructosyl-D-fructosyltransferase (forming di-beta-D-fructofuranose 2,6':2',6-dianhydride); levan fructotransferase; 2,6-beta-D-fructan lyase (di-beta-D-fructofuranose-2,6':2',6-dianhydri • • •