Bacillus amyloliquefaciens levansucrase-catalyzed the synthesis of fructooligosaccharides, oligolevan and levan in maple syrup-based reaction systems

Maple syrups with selected degree Brix (°Bx) (15, 30, 60) were investigated as reaction systems for levansucrase from Bacillus amyloliquefaciens. The enzymatic conversion of sucrose present in the maple syrup and the production of the transfructosylation products were assessed over a time course of 48 h. At 30 °C, the use of maple syrup 30°Bx led to the highest levansucrase activity (427.53 μmol/mg protein/min), while maple syrup 66°Bx led to the highest converted sucrose concentration (1.53 M). In maple syrup 30°Bx, oligolevans (10 < DP ≤ 30) were synthesized as major products (>80%). In maple syrup 66°Bx, the most abundant products were oligolevans at 30 °C and levans (DP ≥ 30) at 8 °C. The acceptor specificity study revealed the ability of B. amyloliquefaciens levansucrase to synthesize a variety of hetero-fructooligosaccharides (FOSs) in maple syrups 15°Bx and 30°Bx enriched with various disaccharides, with lactose being the preferred fructosyl acceptor. The current study is the first to investigate maple-syrup-based reaction systems for the synthesis of FOSs/oligolevans/levans.