Formation of levan from raffinose by levansucrase of Zymomonas mobilis

Levansucrase (EC 2.4.1.10.) of Zymomonas mobilis 113S can perform the polymerisation of fructose moiety from raffinose to levan concomitantly with a release of non-catabolised melibiose into the medium. The kinetic parameters of the levansucrase-catalysed reaction provide even higher reaction velocities on raffinose as compared to sucrose, particularly at low osubstrate concentrations. A decreased value in the number of the average molecular mass (M-n = 1693 kDa), an increased intrinsic viscosity (eta = 49.47 cm(3)/g), and a diminished Huggin's constant (K' = 0.67) are intrinsic to the levan synthesis from raffinose, indicating certain structural peculiarities compared to a polysaccharide obtained from sucrose (M-n = 1851 kDa, [17] 42.47 cm(3)/g, K' = 1.21).