title: Preparation and preliminary characterization of exopolysaccharides by yeast Rhodotorula acheniorum MC.
abstract: The effects of various carbon and nitrogen sources on the synthesis of exopolysaccharides by Rhodotorula acheniorum MC were studied. The dynamic viscosity of cell-free culture broths during exopolysaccharide synthesis were measured. The highest values for the viscosity (10.14 MPa.s) and crude polysaccharide productivity (6.6 g/L) were obtained in a medium supplied with 5% sucrose. Ammonium sulfate was the most favorable nitrogen source for exopolysaccharide synthesis. The value of pH played a determinant role, and the obligatory condition for exopolysaccharide production was low (pH 1.7-2.0) during the fermentation. The chemical composition and sugar constituents of the crude exopolysaccharides were determined. Mannose was the main monosaccharide component, and its concentration was the highest (69.13%) in the crude exopolysaccharide synthesized in the medium that included 5% sucrose as a carbon source.
authors.affiliation: Laboratory of Applied Microbiology, Bulgarian Academy of Sciences, Plovdiv, Bulgaria.
authors.forename: D
authors.initials: D
authors.lastname: Grigorova
authors.forename: K
authors.initials: K
authors.lastname: Pavlova
authors.forename: I
authors.initials: I
authors.lastname: Panchev
mesh_terms: D003470:Culture Media; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D009584:Nitrogen / Q000378:metabolism; D011134:Polysaccharides / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D012248:Rhodotorula / Q000378:metabolism*
chemical_list: D003470:Culture Media; D011134:Polysaccharides; D009584:Nitrogen