Composition Analysis of Aluminum-Philic Organic Matters Isolated from Capsule of Microcystis aeruginosa

Abstract

 Microcystis aeruginosa is a bloom-forming cyanobacterium which causes coagulation inhibition in drinking water treatment. Previous studies on algal organic matters (AOM) of M. aeruginosa, especially on its capsule, have suggested that AOM inhibit coagulation with polyaluminum chloride by forming complex with aluminum in coagulant. In this study, organic matters having high affinity with aluminum ion were isolated from the capsule of M. aeruginosa using affinity chromatography. Molecular size fractionation analysis on isolated organic matters showed no protein peaks and one saccharides peak. This saccharides contained glucose, mannose, and an acidic saccharide. Acidic saccharides have carboxylic radicals in its molecular structure, which enhances adsorption of the saccharides to metals. These results suggested that carboxylic radicals within acidic saccharides of M. aeruginosa capsule form complexes with aluminum ion and inhibit coagulation.