| Abstract |
Polysaccharide analyses were performed on cultures of Microcystis aeruginosa f. aeruginosa Kützing, M. aeruginosa f. flos aquae (Wittrock) Elenkin, M. viridis (A. Brown) Lemmermann, M. wesenbergii Komárek, and toxic (PCC 7941) and nontoxic (PCC 7005) strains of an unidentified Microcystis. The amount of polysaccharide produced and the monosaccharide composition of the mucilages produced by each of these strains were determined. The extracellular polysaccharides (EPS) of Microcystis sp., M. aeruginosa f. aeruginosa, M. aeruginosa f. flos aquae, and M. viridis were composed of the neutral sugars rhamnose, fucose, xylose, mannose, glucose, and uronic acids, whereas those of M. wesenbergii contained only uronic acids. The envelope polysaccharides (CPS) of most strains, when extracted by saline phosphate buffer in the cold (cCPS) and in hot water (hCPS), contained glucose, galactose, and uronic acids. However, the hCPS of M. wesenbergii also had rhamnose and xylose, and the cCPS of Microcystis PCC 7005 was composed of mannose, glucose, arabinose, and uronic acids. Trehalose was detected only in the EPS and CPS of M. viridis. Elucidating polysaccharide production and composition may contribute to better understanding of the taxonomy, biochemistry, and ecology of Microcystis.
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