Extracellular polysaccharide production by thraustochytrid protists.
Four strains of marine stramenopilan protists, the thraustochytrids, were studied for their ability to produce extracellular polysaccharides (EPSs). Observations by light and scanning electron microscopy revealed the production of a matrix of EPS around groups of cells in stationary cultures. EPS in shake culture filtrates ranged from 0.3 to 1.1 g/L. EPS production, which was studied in greater detail in 2 isolates, SC-1 and CW1, increased with age of cultures, reaching a peak in the stationary phase. Anion exchange chromatography yielded a single fraction of the EPS of both species. The EPS contained 39% to 53% sugars, besides proteins, lipids, uronic acids, and sulfates. Molecular weight of the EPS produced by SC-1 was approximately 94 kDa, and that of CW1, 320 kDa. Glucose formed the major component in the EPS of both isolates-galactose, mannose, and arabinose being the other components. Cultures of both isolates survived air-drying up to a period of 96 hours, suggesting a role for EPS in preventing desiccation of cells.
Jain
Ruchi
R
National Institute of Oceanography, Dona Paula, Goa, 403 004, India.
Raghukumar
Seshagiri
S
Tharanathan
R
R
Bhosle
N B
NB
D000818:Animals; D002244:Carbon / Q000378:metabolism; D002852:Chromatography, Ion Exchange; D056890:Eukaryota / Q000378:metabolism* / Q000648:ultrastructure; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis / Q000302:isolation & purification*; D008855:Microscopy, Electron, Scanning; D008970:Molecular Weight; D011134:Polysaccharides / Q000096:biosynthesis / Q000302:isolation & purification*; D013045:Species Specificity
D016326:Extracellular Matrix Proteins; D011134:Polysaccharides; D002244:Carbon