As expected, the sucrose hydrolysis by levansucrase from B.
amyloliquefaciens at 8 ◦C proceeded with a lower rate as compared
to 30 ◦C (Fig. 1). Contrary to 30 ◦C, the transfructosylation reaction
became dominant at the later stage of the time course (12–48 h)
in maple syrup 15◦Bx at 8 ◦C (Fig. 1C). Similarly, Rairakhwada et al.
(2010) have reported that the optimum transfructosylation temperature
of B. amyloliquefaciens levansucrase was around 4 ◦C. On
the other hand, the experimental results showed a similar trend of
the reaction selectivity for B. amyloliquefaciens levansucrase at 8 ◦C
and 30 ◦C in the maple syrup 30◦Bx (Fig. 1B) with the transfructosylation
reaction being preferentially catalyzed at the advanced
stage of the reaction. Contrary to maple syrup 15◦Bx and 30◦Bx,
low conversion of sucrose through the hydrolysis and the transfructosylation
reactions was obtained in the maple syrup 60◦Bx at
8 ◦C reaching 7.20% and 8.05% at 48 h, respectively (Fig. 1A). These
resultsmaydue to the limitedmassdiffusional transfer in the highly
viscous maple syrup 66◦Bx at 8 ◦C as well as to the low levansucrase
activity at low temperature.