EXTRACELLULAR POLYSACCHARIDES OF GREEN ALGAE

Abstract

Eighteen unicellular or colonial green algae, mostly Chlamydomonas species, were isolated from soil or fresh water and grown in mass culture. All of these species liberated some soluble polysaccharides into the growth medium. This material constituted 25% of the total organic matter produced by the cells of Chlamydomonas mexicana. Comparable quantities were isolated from other species by extraction of the cells with hot water or dilute alkali.In all species but one, galactose and arabinose were the main components of the polysaccharides. In Chlamydomonas ulvaënsis, glucose and xylose predominated. Associated sugar moieties included fucose, rhamnose, mannose, uronic acids, and several unidentified components. These constituents were separated and identified by paper chromatography.The role of such polysaccharides in the ecology of soil and natural waters is discussed.