Structure and function of polysaccharide produced by lactic acid bacteria aimed to add biological activity to yoghurt

德布鲁克氏乳杆菌胞外多糖。采用阴离子交换色谱法将保加利亚菌OLL 1073R-1分离为中性和酸性多糖。糖谱分析和^1H NMR谱分析表明，中性和酸性多糖由含有半乳糖（Gal）和葡萄糖（Glc）的五糖重复单元组成，摩尔比为1. 3:1. 0，表观分子量分别为1. 2 × 10^6Da和1.1 × 10^6Da。酸性多糖中含有少量（0.1%）磷。酸性多糖刺激小鼠脾细胞和Peyer's斑块的有丝分裂反应，但对胸腺细胞没有刺激作用。多糖在最高刺激下的光学浓度为160杯/毫升。有丝分裂活性在24h开始显著增加，刺激48h后反应最高。氢氟酸降解的去磷酸化降低了淋巴细胞的有丝分裂活性。德布鲁克氏乳杆菌产生的磷酸多糖。OLL1073R-1是一种有效的b细胞依赖性有丝分裂原，其中磷酸基团作为有丝分裂诱导的触发器。在体内和体外短期研究中，研究了APS和NPS对巨噬细胞（MPHI）功能的影响。腹腔注射APS可显著增强腹膜MPHI的吞噬活性，而NPS则无此作用。巯基乙酸诱导的MPHI细胞毒活性在浓度为100mug/ml的APS处理6h后显著升高，且活性高于NPS处理。这些结果表明，保加利亚酵母OLL1073R-1发酵食品有可能发展成为具有生物学功能的特殊食品。

The exocellular polysaccharide from Lactobacillus delbrueckii ssp.bulgaricus OLL 1073R-1 was fractionated into neutral and acidic polysaccharides by anion-exchange chromatography. Sugar analysis and ^1H NMR spectroscopy revealed that the neutral and acidic polysaccharides were composed of pentasaccharide repeating units containing galactose (Gal) and glucose (Glc) in the molar ratio of I.3 : I.0, and the apparent molecular weight were I.2 x 1O^6Da and 1.1 x 10^6Da, respectively. A slight amount (0.1%) of phosphorus was contained in the acidic polysaccharide.The acidic polysaccharide stimulated mitogenic responses of murine splenocytes and Peyer's patches but not of thymocytes. The optical concentration of the polysaccharide at the highest stimulation was 160 mug/ml. A significant increase of mitogenic activity was initiated at 24h, and the highest response was obtained after stimulation for 48h. Dephosphorylation by hydrofluoric acid degradation reduced the mitogenic activity in lymphocytes. The phosphopolysaccharide produced by Lactobacillus delbrueckii ssp.bulgaricus OLL1073R-1 is a potent B-cell-dependent mitogen in which the phosphate group acts as a trigger of the mitogenic induction.The effect of APS and NPS on macrophage (MPHI) functions was examined in vivo and in vitro in short-term studies. The phagocytic activity of peritoneal MPHI was significantly augmented by the intraperitoneal administration of APS,but not by NPS.The cytotoxic activity of thioglycolate-induced MPHI was significantly increased when it was treated with APS at a concentration of 100mug/ml for 6h, which activity was greater than that NPS treatment.These findings indicate the possibility that fermented food products made with L.bulgaricus OLL1073R-1 may be developed as special foods with biological functions.