Hou C T, Ahlgren J A, Brown W, Nicholson J J
Oil Chemical Research Unit, National Center for Agricultural Utilization Research, USDA, Peoria, IL 61604, USA.
J Ind Microbiol. 1996 Feb;16(2):129-33. doi: 10.1007/BF01570073.
A bacterium isolated from soil and identified as Agrobacterium sp produced a water-soluble extracellular polysaccharide capable of producing highly viscous solutions. Gas chromatographic analysis revealed a sugar composition of glucose, galactose and mannose in the molar ratio of 7.5:2.4:1, together with 3.7% (w/w) pyruvic acid. Methylation analyses showed the presence of (1-->3)-, (1-->4)- and (1-->6)-linked glucose, (1-->3)- and (1-->4, 1-->6)-linked galactose and a small portion of (1-->3)-linked mannose residues. Succinic acid was not present. The molecular weight of the polysaccharide was estimated by light scattering to be 2 x 10(6) Da. The viscosity of solutions containing the polysaccharide remained constant from pH 3 to 11, and decreased by 50% when heated from 5 to 55 degrees C. Maximum yield of the polysaccharide, 20 g L-1, was reached in 48 h at 30 degrees C incubation.
从土壤中分离出的一种被鉴定为土壤杆菌属的细菌产生了一种水溶性细胞外多糖，该多糖能够形成高粘性溶液。气相色谱分析显示，其糖组成为葡萄糖、半乳糖和甘露糖，摩尔比为7.5:2.4:1，还含有3.7%（w/w）的丙酮酸。甲基化分析表明存在（1→3）-、（1→4）-和（1→6）-连接的葡萄糖，（1→3）-和（1→4,1→6）-连接的半乳糖以及一小部分（1→3）-连接的甘露糖残基。不存在琥珀酸。通过光散射估计该多糖的分子量为2×10⁶ Da。含该多糖溶液的粘度在pH 3至11范围内保持恒定，从5℃加热到55℃时粘度降低50%。在30℃培养48小时时，多糖的最大产量达到20 g L⁻¹。
