Three Enzymes Activities of Levansucrase from Zymomonas mobilis ATCC 10988 and Rahnella aquatilis ATCC 33071

Levansucrase (EC 2.4.1.10) is capable of producing levan from sucrose as a substrate. The enzyme is known to not only catalyze the transfer reaction producing levan, but also to hydrolyze levan. The optimum temperature of R. aquatilis levansucrase for levan formation was 37oC, whereas that of Z. mobilis was 4oC, under the experimental conditions. Levan hydrolysis reactions from both levansucrases were temperature dependent; high temperature (20oC) was more favorable than low temperature (4oC) by 4 times. In both enzymes, initial levan hydrolysis activity was almost accounted to 1% of initial levan formation activity. The results allow the estimation of the fructose release rate in enzyme processing conditions.