A simple and efficient method for the purification of membrane-bound levansucrase from Zymomonas mobilis

A new and efficient method for the purification of levansucrase from cell-f ree extracts of a flocculant mutant: of Zymomonas mobilis ATCC 10988 was de veloped. Levansucrase activity was almost completely recovered and purified by a factor of 15 after precipitation with 0.1 M MnCl2 as a first capturin g step. The enzyme was homogeneously purified by ultrafiltration and anion- exchange chromatography and exhibited a levan-forming activity of 39.2 U mg (-1). The native enzyme formed large aggregates with an apparent molecular mass of more than 10(6) Da as determined by size-exclusion chromatography, whereas denaturing SDS-PAGE indicated an apparent molecular mass of 50 kDa for the subunits.