Laboratoire Microorganismes et Biomolécules Actives (LR03ES03), Faculté des Sciences de Tunis, Université Tunis El Manar, Tunis, Tunisia; Department of Microbial and Plant Biotechnology. Margarita Salas Biological Research Centre, CIB-CSIC, Madrid, Spain.
Laboratoire Microorganismes et Biomolécules Actives (LR03ES03), Faculté des Sciences de Tunis, Université Tunis El Manar, Tunis, Tunisia.
Carbohydr Polym. 2021 Feb 1;253:117254. doi: 10.1016/j.carbpol.2020.117254. Epub 2020 Oct 18.
High molecular weight dextrans improve the rheological properties of fermented products and have immunomodulatory and antiviral activity. We report on 5.84 × 10-2.61 × 10 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.
高分子量葡聚糖能改善发酵产品的流变学特性，并具有免疫调节和抗病毒活性。我们报告了由乳球菌 AV1n、魏斯氏菌 AV2ou 和魏斯氏菌 V30 和 FS54 菌株产生的 5.84×10-2.61×10 Da 的葡聚糖。葡聚糖蔗糖酶通过蔗糖水解同时生成果糖来催化葡聚糖的合成。通过同工酶图谱检测到这四种细菌的葡聚糖蔗糖酶分子量约为 160 kDa。每种细菌的葡聚糖产生和代谢通量之间的相互作用都不同。所有细菌都产生乳酸，除了 AV2ou 之外，还从果糖合成甘露醇。FS54 水解葡聚糖蓝，并且这种细菌产生的葡聚糖浓度在静止期下降。AV1n 在合成葡聚糖的条件下与 Caco-2 细胞和聚苯乙烯板的结合更高。因此，这是首次发现与葡聚糖蔗糖酶能力相关的魏斯氏菌葡聚糖酶，以及葡聚糖对细菌粘附和聚集特性的积极影响。
