KNAW Repository

Isolation and characterization of extracellular polysaccharides from the epipelic diatoms Cylindrotheca closterium and Navicula salinarum

Staats, N. and de Winder, B. and Stal, L.J. and Mur, L.R. (1999) Isolation and characterization of extracellular polysaccharides from the epipelic diatoms Cylindrotheca closterium and Navicula salinarum. European Journal of Phycology, 34, 161-169. ISSN 0967-0262.

[img]PDF - Published Version
Restricted to KNAW only

370Kb

Official URL: http://dx.doi.org/10.1080/09670269910001736212

Abstract

The production and composition of extracellular polymeric substances (EPS) in axenic batch cultures of the benthic marine epipelic diatoms Navicula salinarum and Cylindrotheca closterium were investigated. EPS was secreted into the medium and the bulk was loosely associated with the cells. Neither N. salinarum nor C. closterium formed a well-defined polysaccharide capsule. EPS of both N. salinarum and C. closterium consisted predominantly of polysaccharide but small quantities of protein were present as well. EPS also contained uronic adds and SO42- groups. Analysis of monosaccharides using gas chromatography showed that for both species glucose and xylose were the main constituents, but several other monosaccharides were present in smaller quantities. Two fractions of EPS were distinguished: a small amount was secreted into the medium and a second fraction was extracted in water at 30 degrees C. For both species the two fractions differed somewhat in composition, indicating that they represented two different types of EPS. The EPS produced by N. salinarum and by C. closterium differed in their composition. The rate of EPS production in batch culture was highest during the transition from exponential growth to stationary growth. Negatively charged groups such as uronic acids and sulphated sugars determine the adhesion capacity of EPS and probably play an important role in the stabilization of intertidal sediments on which these diatoms grow and produce biofilms. [KEYWORDS: Cylindrotheca closterium; diatoms; EPS; extracellular polymeric substances; microphytobenthos; Navicula salinarum; polysaccharide; sediment stabilization.]

Item Type:Article
Institutes:Nederlands Instituut voor Ecologie (NIOO)
ID Code:10785
Deposited On:25 Nov 2011 01:00
Last Modified:31 Mar 2014 09:57

Repository Staff Only: item control page