Department of Microbiology, University of Ibadan, Ibadan, Oyo, State, Nigeria; Microbial Resources Division, Institute of Bioresources and Sustainable Development (IBSD), Imphal-795001, Manipur, India.
Department of Microbiology, University of Ibadan, Ibadan, Oyo, State, Nigeria.
Int J Biol Macromol. 2018 May;111:514-525. doi: 10.1016/j.ijbiomac.2018.01.060. Epub 2018 Jan 11.
The production, optimization, and characterization of exopolysaccharide (EPS) from Weissella confusa OF126 and the in-vitro probiotic potentials of this strain was investigated. The EPS produced on sucrose modified-MRS broth was characterized. The purified EPS had an average molecular weight of 1.1 × 10 Da. HPLC analysis revealed the presence of glucose monomers, indicating its homopolysaccharide nature. The structural characteristics of the EPS were investigated by FTIR, and NMR spectroscopy. FTIR spectroscopy revealed the presence of hydroxyl, carboxyl, N-acetyl and amine groups. NMR analysis confirmed that the EPS contained α-(1 → 6) linkage and α-(1 → 3) branched linkage. The EPS showed strong in-vitro antioxidant activity. Four significant factors were optimized using Central Composite Design (CCD) and Response Surface Methodology (RSM). The predicted optimum conditions for EPS production were cultivation time (48.50 h), sucrose concentration (24.00 g/L), pH (7.00) and yeast extract (2.50%).The EPS produced was predicted to be 3.10 g/L, while the experimental yield was 3.00 g/L. This strain was found to possess desirable probiotic attributes by its ability to survive at pH 2.0 and in the presence of bile salts (0.50% (w/v)) for 4 h. The results obtained from this study demonstrate W. confusa OF126 as a promising probiotic and the EPS produced can find useful applications in industries.
本研究旨在探讨发酵乳杆菌 OF126 胞外多糖（EPS）的生产、优化和特性及其作为潜在益生菌的体外特性。在改良 MRS 蔗糖培养基上对 EPS 进行了特性分析。所得到的 EPS 的平均分子量为 1.1×10 Da。HPLC 分析表明其单糖组成为葡萄糖，表明其为同多糖。FTIR 和 NMR 光谱分析了 EPS 的结构特征。FTIR 光谱显示存在羟基、羧基、N-乙酰基和胺基。NMR 分析证实 EPS 含有α-(1→6)键和α-(1→3)支链键。EPS 表现出较强的体外抗氧化活性。通过中心组合设计（CCD）和响应面法（RSM）对 4 个显著因素进行了优化。预测 EPS 生产的最佳条件为培养时间（48.50 h）、蔗糖浓度（24.00 g/L）、pH（7.00）和酵母提取物（2.50%）。预测 EPS 的产量为 3.10 g/L，而实验产量为 3.00 g/L。该菌株在 pH 2.0 和 0.50%（w/v）胆盐存在下 4 h 后仍能存活，表现出良好的益生菌特性。本研究结果表明发酵乳杆菌 OF126 具有作为潜在益生菌的潜力，所产生的 EPS 在工业中可能具有有用的应用。
