中文摘要：

由鞘氨醇单胞菌（Sphingomonas sp．）NXO2合成了一种具有增稠性、假塑性、成凝胶特性和乳化活性的新型生物聚合物．定性分析表明，聚合物由糖类、脂类和多肽构成，其所占比例分别为34．8％，63．1％和1．5％．用凝胶渗透色谱一多角度激光光散射联用法测得聚合物的重均分子量和数均分子量分别为408000和382000，分子量分布Mw／Mn为1．07．该聚合物的单糖组成为葡萄糖、甘露糖、鼠李糖和葡萄糖醛酸，脂类由十六碳及十八碳脂肪酸组成．由于在聚合物的氨基酸组成中天冬氨酸和谷氨酸两种酸性氨基酸占23．3％，因此可以采用酸沉法提取，从而大幅度降低其生产成本．

英文摘要：

According to the characteristics of morphology, physiology and biochemistry and the comparison of 16S rDNA sequence, strain NXO2 was identified as a new species of the genus Sphingomonas. A novel biopolymer synthesized by Sphingomonas sp. strain NXO2 with thickening, pseudoplastic, gelling and emulsification. The results of qualitative analysis show that biopolymer is consisted of carbohydrates, lipids and peptides, the proportion is 34.8% , 63.1% and 1.5% , respectively. The weight average molar mass and number average molar mass of biopolymer was measured to be 408000 and 382000 by GPC-MALLS, and the polydiversity （Mw/Mn ） was calculated to be 1.07. The monosaceharide compositions were glucose, mannose, rhamnose and glucuronic acid; the lipid portion was hexadecanoic acid and stearie acid; the proportion of glutamic acid and aspartie acid was 23.3% of the total amino acid content, so the polymer could be precipitated with acid, which reduced the production cost significantly.