초록
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 32gL<SUP>-1</SUP> dextran in the tomato-juice-sucrose medium when cultured at 28<SUP>o</SUP>C for 48h, 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 6.35x10<SUP>5</SUP>Da, a linear backbone composed of consecutive α-(1→6)-linked d-glucopyranosyl units and approximately 6% α-(1→3) branches.