Production and properties of exopolysaccharide by Rhodotorula acheniorum MC

Production of exopolysaccharide by Rhodotorula acheniorum MC was studied. Polysaccharide synthesis, biomass concentration, sugar consumption, pH value, dynamic viscosity and NH4+ concentration were studied in batch fermentation under aeration 0.75 vvm and agitation 500 rpm. In a medium containing 50 g/litre sucrose the maximum amount of exopolysaccharide 6.2 g/litre and 10.2 g/litre biomass were obtained at 96 h. The chemical composition of the polysaccharide was carbohydrate - 98.2%, protein 1.2%, ash - 0.4%, monosaccharide: mannose - 92.8% and glucose - 7.2%. The interaction between the polysaccharide synthesized by Rh.acheniorum MC polymer and xanthan showed synergistic effect. The viscosity of a mannan-xanthan (20:80) mixture was 40% higher as compared to the xanthan alone. (C) 2000 Canadian Institute of Food Science and Technology. Published by Elsevier Science Ltd. All rights reserved.