TABLE 4.
Glycosyl linkage analysis of EPS (HMW fraction) from NGR234 and mutant NGRΩexoK
| Glycosyl linkagea | NGR234
|
NGRΩexoK
|
Ratio in EPS structureb | ||
|---|---|---|---|---|---|
| Total area (%) | Area ratio | Total area (%) | Area ratio | ||
| T-Glucose | 0.8 | 0.1 | 0.6 | 0.1 | |
| T-Galactose (f) | 0.4 | 0.0 | 4.0 | 0.3 | |
| 3-Galactose | 13.1 | 1.2 | 14.2 | 1.2 | 1 |
| 6-Glucose | 11.2 | 1.0 | 12.1 | 1.0 | 1 |
| 4-Glucose | 38.5 | 3.4 | 38.2 | 3.2 | 3 |
| 3-Glucuronic acid | 7.9 | 0.7 | 7.0 | 0.6 | 1 |
| 4-Glucuronic acid | 9.4 | 0.8 | 8.1 | 0.7 | 1 |
| 4,6-Glucose | 9.5 | 0.8 | 8.1 | 0.7 | 1 |
| 4,6-Galactose | 9.2 | 0.8 | 7.6 | 0.6 | 1 |
a
Glycosyl linkages were determined by GC-MS analysis of partially methylated alditol acetate derivatives. T, terminal residue; f, furanose form.
b
The two strains have similar glycosyl linkage ratios that are consistent with the structure of the nonasaccharide repeating subunit (Fig 1A).