The characteristics of the growth of Leuconostoc mesenteroides BD1710 and the synthesis of dextran in
tomato juice supplemented with 15% sucrose were assayed. L. mesenteroides BD1710 could synthesize
approximately 32 g L−1 dextran in the tomato-juice–sucrose medium when cultured at 28 ◦C for 48 h,
which was on the same level as the dextran yield in a chemically defined medium. The viscosity of the
cultured tomato-juice–sucrose medium with various dextran contents was also measured. The results
of the monosaccharide composition, molecular-weight distribution, Fourier transform infrared spectra
(FTIR) and nuclear magnetic resonance spectra (NMR) showed that the polysaccharide synthesized by L.
mesenteroides BD1710 in the tomato-juice–sucrose medium was dextran with a peak molecular weight of
6.35 × 105 Da, a linear backbone composed of consecutive -(1→6)-linked d-glucopyranosyl units and
approximately 6% -(1→3) branches.