Stephan M P, Fontaine T, Previato J O, Mendonça-Previato L
Laboratory of Biochemistry, National Centre of Research on Agrobiology-EMBRAPA/CNPAB-Rio de Janeiro-Brazil.
Microbiol Immunol. 1995;39(4):237-42. doi: 10.1111/j.1348-0421.1995.tb02195.x.
Capsular polysaccharides (CPSs) from six representative strains of Acetobacter diazotrophicus were isolated and fractionated by gel filtration and anion-exchange chromatography. Purified CPSs obtained in the non-adsorbed fraction of a DEAE-Sephadex A-25 column were qualitatively and quantitatively analyzed for sugar composition. Uronic acid and amino sugars were not detected in all purified CPSs. Basically the CPSs of A. diazotrophicus are composed of rhamnose, mannose, galactose and glucose. The presence of fucose was only observed in the CPS of strains PR2 and PAL3. Based on these results, the six strains of A. diazotrophicus could be divided into four groups according to the sugar content of their capsules: (i) fucose-containing capsules (PR2 and PAL3, localized in roots), (ii) mannose-rich capsule (PAL5, localized in root), (iii) capsules with a high ratio of hexose to rhamnose (PR4 and PR20, localized in stems) and (iv) capsules with a low ratio of hexose to rhamnose (PR14, localized in rhizosphere). For all CPSs, sodium dodecy sulfate-polyacrylamide gel electrophoresis showed diffuse bands of slow mobility in silver-stained gels. The different CPS migration patterns could not be correlated with sugar composition. The purified CPS of strain PAL3 was found to be immunogenic and immunochemically similar to the CPS of strain PR2. The serological specificity to CPS of strains PAL3 and PR2 correlated well with the presence of focuse, indicating that this deoxyhexose is immunodominant.(ABSTRACT TRUNCATED AT 250 WORDS)
从六株代表性固氮醋杆菌菌株中分离出荚膜多糖（CPSs），并通过凝胶过滤和阴离子交换色谱法进行分级分离。对在DEAE - 葡聚糖A - 25柱的未吸附级分中获得的纯化CPSs进行糖组成的定性和定量分析。在所有纯化的CPSs中均未检测到糖醛酸和氨基糖。基本上，固氮醋杆菌的CPSs由鼠李糖、甘露糖、半乳糖和葡萄糖组成。仅在菌株PR2和PAL3的CPS中观察到岩藻糖的存在。基于这些结果，根据其荚膜的糖含量，六株固氮醋杆菌可分为四组：（i）含岩藻糖的荚膜（PR2和PAL3，定殖于根中），（ii）富含甘露糖的荚膜（PAL5，定殖于根中），（iii）己糖与鼠李糖比例高的荚膜（PR4和PR20，定殖于茎中）和（iv）己糖与鼠李糖比例低的荚膜（PR14，定殖于根际）。对于所有CPSs，十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳在银染凝胶中显示出迁移缓慢的弥散条带。不同的CPS迁移模式与糖组成无关。发现菌株PAL3的纯化CPS具有免疫原性，并且在免疫化学上与菌株PR2的CPS相似。菌株PAL3和PR2对CPS的血清学特异性与岩藻糖的存在密切相关，表明这种脱氧己糖具有免疫主导性。（摘要截断于250字）
