Biosynthesis and Characterization of Exopolysaccharides and Lipids from Antarctic Yeasts

Abstract

ABSTRACTA laboratory technological scheme for biosynthesis of exopolysaccharides and biomass from Antarctic yeasts and extraction of phospholipids and fatty acids from the biomass was developed. The strains Sporobolomyces salmonicolor AL34, Cryptococcus laurentii AL62, Isolate AL65, Isolate AL66, Cryptococcus laurentii AL100 and Isolate AL102 were selected as active producers of exopolysaccharides, and the biomass was a source of biologically active compounds. The chemical composition of the extracellular polymeric substances was analyzed and it was established that they contained about 80.0 % carbohydrates, 11.4% protein, 6.0 - 9.2% ash, nucleic acids - 4.7 - 6.0% and the biomass contained 10.5 - 13.5 % lipids. The accumulation of polar and non-polar lipids in the biomass produced at submerged and surface cultivation of the strains was studied. The content of phospholipids was found to be 0.1 - 0.4% in the biomas and 6.3 - 50.0% in the lipid fraction. In the submerged and surface cultures of the investigated Antarctic yeasts the long-chain unsaturated fatty acids were predominant (more than 45.0%), mainly oleic acid. High contents of them were found in strain Sp. salmonicolor AL34 (79.0 %) as a result of surface cultivation and Cr. laurentii AL100 (71.3%), and Isolate AL102 (73.4%) at submerged cultivation.