Jiangsu Provincial Key Lab for Organic Slid Waste Utilization, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China.
Bioresour Technol. 2011 May;102(10):6095-103. doi: 10.1016/j.biortech.2011.02.033. Epub 2011 Feb 16.
The optimization, purification and characterization of an extracellular polysaccharide (EPS) from a bacterium Paenibacillus polymyxa SQR-21 (SQR-21) were investigated. The results showed that SQR-21 produced one kind of EPS having molecular weight of 8.96 × 10(5)Da. The EPS was comprised of mannose, galactose and glucose in a ratio of 1.23:1.14:1. The ratio of monosaccharides and glucuronic acid was 7.5:1. The preferable culture conditions for EPS production were pH 6.5, temperature 30°C for 96 h with yeast extract and galactose as best N and C sources, respectively. The maximum EPS production (3.44 g L(-1)) was achieved with galactose 48.5 g L(-1), Fe(3+) 242 μM and Ca(2+) 441 μM. In addition, the EPS showed good superoxide scavenging, flocculating and metal chelating activities while moderate inhibition of lipid peroxidation and reducing activities were determined. These results showed the great potential of EPS produced by SQR-21 to be used in industry in place of synthetic compounds.
研究了一株多粘类芽孢杆菌（Paenibacillus polymyxa SQR-21，SQR-21）胞外多糖（EPS）的优化、纯化和性质。结果表明，SQR-21 产生了一种分子量为 8.96×10(5)Da 的 EPS。该 EPS 由甘露糖、半乳糖和葡萄糖组成，摩尔比为 1.23:1.14:1。单糖和葡萄糖醛酸的比例为 7.5:1。EPS 生产的最佳培养条件为 pH6.5、温度 30°C、培养 96 h，酵母提取物和半乳糖分别为最佳氮源和碳源。当半乳糖 48.5 g/L、Fe(3+) 242 μM 和 Ca(2+) 441 μM 时，EPS 的产量达到最大（3.44 g/L）。此外，EPS 表现出良好的超氧阴离子清除、絮凝和金属螯合活性，同时具有中等的抑制脂质过氧化和还原活性。这些结果表明，SQR-21 产生的 EPS 具有很大的工业应用潜力，可以替代合成化合物。
