Isolation and physicochemical characterization of soluble scleroglucan from Sclerotium rolfsii. Rheological properties, molecular weight and conformational characteristics

J.I. FARIÑA; F. SIÑERIZ; O.E. MOLINA; N.I. PEROTTI

CARBOHYDRATE POLYMERS

Elsevier

Lugar: Amsterdam; Año: 2001 vol. 44 p. 41 - 50

0144-8617

Scleroglucan produced by Sclerotium rolfsii ATCC 201126 exhibited pseudoplastic behaviour and an exponential relationship between apparent viscosity and polymer concentration. Viscosity showed strong heat-stability (100°C/60 min). Tolerance up to 20% w/v NaCl and over a wide pH range (0–13) was also found. A sharp decrease on viscosity at NaOH concentrations higher than 0.15 M was observed due to dissociation of the triple-helix. According to intrinsic viscosity determinations and gel filtration chromatography on Sepharose CL-4B, the weight-average molecular weight of native polysaccharide was about 5×10^6 Da for the triplex and 1.6×10^6 Da for the random coil. These values, in addition to the change in complexation with Congo Red, support the idea of the triple-helical conformation in neutral or slightly alkaline solutions (