Characterisation of extracellular polysaccharides produced by Crypthecodinium cohnii

• Published in: Applied microbiology and biotechnology Vol. 57; no. 3; pp. 395 - 400
• Main Authors: Swaaf, M.E. de, Grobben, G.J, Eggink, G, Rijk, T.C. de, Meer, P. van der, Sijtsma, L
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.10.2001; Springer Nature B.V
• Subjects: Agrotechnological Research Institute; algal culture; Animals; Bacteria; Biological and medical sciences; Biotechnology; Chromatography, High Pressure Liquid; Crypthecodinium; Crypthecodinium cohnii; Dinoflagellida - growth & development; Dinoflagellida - metabolism; docosahexaenoic acid; Docosahexaenoic Acids - metabolism; Electrophoresis, Capillary; Fatty acids; fucose; Fundamental and applied biological sciences. Psychology; galactose; Glucose; Glucose - analysis; Glucose - metabolism; Instituut voor Agrotechnologisch Onderzoek; mannose; Methods. Procedures. Technologies; microalgae; Microbial engineering. Fermentation and microbial culture technology; Molecular Weight; oxygen; Oxygen transfer; polysaccharides; Polysaccharides - biosynthesis; Polysaccharides - chemistry; Polyunsaturated fatty acids; Saccharides; uronic acids; Viscosity; xylose; yeast extract; Yeasts; Viscosity; Algae; Polyunsaturated fatty acid; Microorganism culture; Docosahexaenoic acid; Extracellular; Polysaccharide; Thallophyta
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s002530100788

The valuable polyunsaturated fatty acid, docosahexaenoic acid, can be produced by cultivation of the heterotrophic microalga, Crypthecodinium cohnii. During batch growth of C. cohnii on glucose, sea salt and yeast extract for 5 days, so far unreported extracellular polysaccharides were produced. These caused an increased viscosity and a strong drop in the maximum oxygen transfer. The viscosity increased most markedly as cells entered the stationary phase. The polysaccharides varied in size (from 6 kDa to >1,660 kDa) and monomer distribution. A high molecular mass fraction (from 100 kDa to >1,660 kDa) and a medium molecular mass fraction (6-48 kDa) were prepared. The high molecular mass fraction contained (on a molar basis) 71.7% glucose, 13.1% galactose and 3.8% mannose, whereas the medium molecular mass fraction contained 37.7% glucose, 19.8% galactose and 28.1% mannose. Other monomers present in both fractions were fucose, uronic acid and xylose. Monomers were coupled mainly via alpha-(1-3) links. Increased viscosity due to polysaccharide production complicates the development of commercial, high cell-density processes for the production of docosahexaenoic acid.