High molecular weight dextrans improve the rheological properties of fermented products and have immunomodulatory and antiviral activity. We report on 5.84 × 10⁷–2.61 × 10⁸ Da dextrans produced by Leuconostoc lactis AV1n, Weissella cibaria AV2ou and Weissella confusa V30 and FS54 strains. Dextransucrases catalyze dextran synthesis by sucrose hydrolysis concomitant with fructose generation. The four bacteria have dextransucrases with molecular weight of about 160 kDa detected by zymograms. Each bacterium showed different interplay of dextran production and metabolic fluxes. All bacteria produced lactate, and AV2ou apart, synthesized mannitol from fructose. FS54 hydrolyzed dextran blue and the concentration of dextran produced by this bacterium decreased during the stationary phase. The AV1n binding to Caco-2 cells and polystyrene plates was higher under conditions for dextran synthesis. Thus, this is the first instance of a Weissella dextranase, associated with a dextransucrase ability, and of a positive influence of dextran on adhesion and aggregation properties of a bacterium.

高分子量右旋糖酐改善了发酵产物的流变性，并具有免疫调节和抗病毒活性。我们报告了由乳酸隐球菌AV1n ，Weissella cibaria AV2ou和Weissella confusa生产的5.84×10 ⁷ –2.61×10 ⁸ Da葡聚糖V30和FS54菌株。葡聚糖通过蔗糖水解伴随果糖生成来催化葡聚糖合成。四种细菌具有葡聚糖酶，通过酶谱法检测其分子量约为160 kDa。每种细菌表现出不同的葡聚糖产生和代谢通量相互作用。所有细菌均产生乳酸，而AV2ou则由果糖合成甘露醇。FS54水解了葡聚糖蓝，在稳定期该细菌产生的葡聚糖浓度降低。在葡聚糖合成的条件下，AV1n与Caco-2细胞和聚苯乙烯板的结合较高。因此，这是Weissella的第一个实例 葡聚糖酶，与葡聚糖酶的能力有关，并且对细菌的黏附和聚集特性有积极影响。