TY - JOUR
T1 - Characterisation of extracellular polysaccharides produced by Crypthecodinium cohnii
AU - de Swaaf, M.E.
AU - Grobben, G.J.
AU - Eggink, G.
AU - de Rijk, T.C.
AU - van der Meer, P.
AU - Sijtsma, L.
PY - 2001
Y1 - 2001
N2 - 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 !-(1-3) links. Increased viscosity due to polysaccharide production complicates the development of commercial, high cell-density processes for the production of docosahexaenoic acid.
AB - 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 !-(1-3) links. Increased viscosity due to polysaccharide production complicates the development of commercial, high cell-density processes for the production of docosahexaenoic acid.
U2 - 10.1007/s002530100788
DO - 10.1007/s002530100788
M3 - Article
SN - 0175-7598
VL - 57
SP - 395
EP - 400
JO - Applied Microbiology and Biotechnology
JF - Applied Microbiology and Biotechnology
IS - 3
ER -