Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja, University of Granada, 18071 Granada, Spain.
Molecules. 2012 Jun 12;17(6):7103-20. doi: 10.3390/molecules17067103.
We have studied the extracellular polysaccharide (EPS) produced by the type strain, M8(T), of the halophilic bacterium Halomonas almeriensis, to ascertain whether it might have any biotechnological applications. All the cultural parameters tested influenced both bacterial growth and polysaccharide production. EPS production was mainly growth-associated and under optimum environmental and nutritional conditions M8(T) excreted about 1.7 g of EPS per litre of culture medium (about 0.4 g of EPS per gram of dry cell weight). Analysis by anion-exchange chromatography and high-performance size-exclusion chromatography indicated that the exopolysaccharide was composed of two fractions, one of 6.3 × 10(6) and another of 1.5 × 10(4) Daltons. The monosaccharide composition of the high-molecular-weight fraction was mannose (72% w/w), glucose (27.5% w/w) and rhamnose (0.5% w/w). The low-molecular-weight fraction contained mannose (70% w/w) and glucose (30% w/w). The EPS has a substantial protein fraction (1.1% w/w) and was capable of emulsifying several hydrophobic substrates, a capacity presumably related to its protein content. The EPS produced solutions of low viscosity with pseudoplastic behaviour. It also had a high capacity for binding some cations. It contained considerable quantities of sulphates (1.4% w/w), an unusual feature in bacterial polysaccharides. All these characteristics render it potentially useful as a biological agent, bio-detoxifier and emulsifier.
我们研究了嗜盐菌 Halomonas almeriensis 模式菌株 M8(T)产生的胞外多糖 (EPS)，以确定它是否具有任何生物技术应用的潜力。所有测试的培养参数都影响细菌生长和多糖产生。EPS 生产主要与生长相关，在最佳环境和营养条件下，M8(T)每升培养基可分泌约 1.7 克 EPS（约每克干重细胞分泌 0.4 克 EPS）。阴离子交换色谱和高效体积排阻色谱分析表明，该胞外多糖由两个部分组成，一个部分分子量为 6.3×10(6)，另一个部分分子量为 1.5×10(4)。高分子量部分的单糖组成为甘露糖 (72% w/w)、葡萄糖 (27.5% w/w) 和鼠李糖 (0.5% w/w)。低分子量部分含有甘露糖 (70% w/w) 和葡萄糖 (30% w/w)。EPS 具有大量的蛋白质部分 (1.1% w/w)，能够乳化几种疏水性底物，这种能力可能与其蛋白质含量有关。EPS 产生的溶液具有低粘度和假塑性行为。它还具有结合某些阳离子的高能力。它含有相当数量的硫酸盐 (1.4% w/w)，这是细菌多糖的一个不寻常特征。所有这些特性使其有可能作为一种生物制剂、生物解毒剂和乳化剂使用。
