Abstract The linear, 7.3 × 106 Da polysaccharide (PA) was purified from the extracellular polymeric product of Paenibacillus mucilaginosus WL412. Rheological results revealed that PA solution was typical shear-thinning fluid and it was more viscous than xanthan gum solution under the same conditions. Besides, PA formed a weak gel-like structure and the anti-shear, heat-resistant, and saline tolerant abilities were preferable to xanthan gum in the testing temperature range of 10–85 °C on the basis of thixotropy and oscillation analyses. Afterwards, the chemical structure of PA was elucidated by means of methylation-GC/MS, and 1D- and 2D-NMR spectra. PA consisted of three types of glycosides, namely mannoside, glucoside, and galactoside with molar ratio of 1.89:2.11:1.00. Besides, an acetyl group existed in every repeating unit. The possible structure of PA was identified as →4)α-Glc(1 → 2)α-Man(1 → 3)β-Glc(1 → 3)α-Man(6-Ac)(1 → 3)β-Gal(1→. These results indicate that PA is a potential additive for rheological modification, such as thickener and stabilizer.

中文翻译：

---

类芽孢杆菌菌株生产的一种高粘多糖的纯化与表征

摘要 从粘液类芽孢杆菌 WL412 的胞外聚合产物中纯化线性 7.3 × 106 Da 多糖 (PA)。流变学结果表明，PA 溶液是典型的剪切稀化流体，在相同条件下它比黄原胶溶液更粘稠。此外，基于触变性和振荡分析，PA在10-85°C的测试温度范围内形成了弱凝胶状结构，抗剪切、耐热和耐盐能力优于黄原胶。随后，通过甲基化-GC/MS、1D-和2D-NMR光谱阐明了PA的化学结构。PA由三种糖苷组成，即甘露糖苷、葡萄糖苷和半乳糖苷，摩尔比为1.89:2.11:1.00。此外，乙酰基存在于每个重复单元中。