Rheology and characterization of a low viscosity emulsifying exopolymer from desert borne Nostoc calcicola

摘要

Nostoc calcicola produced profuse amount of polysaccharidic exopolymer under P limited conditions. The exopolymer showed a truly pseudoplastic, non-Newtonian, rime independent behaviour with good recovery after shear. It was composed of D-ribose, D-arabinose, L-rhamnose, L-fucose, D-xylose, D-mannose, D-glucose, D-galactose and 3-methyl-D-arabinose. IR spectra showed bands at 1250 and 820 cm(-1), characteristic of sulphate residue. The exopolymer showed, good emulsifying and antimicrobial activity. It absorbed 282 g H2O.g(-1) exopolymer. The possible applications of the exopolymer in pharmaceutical, food and oil recovery industry have been discussed