title: Cellular proteins of Microcystis aeruginosa inhibiting coagulation with polyaluminum chloride.
abstract: Cyanobacterial growth in semi-closed water areas such as reservoirs brings about a coagulation inhibition in a drinking water treatment system, but the inhibitory substances and mechanisms involved have yet to be elucidated. In this study, proteins having a high affinity with polyaluminum chloride (PACl) were isolated from organic substances produced by Microcystis aeruginosa with the affinity chromatography technique. Both extracellular organic matter (EOM) and cellular organic matter (COM) disturbed the flocculation of suspended kaolin with PACl, but it was likely that nonproteinous substances in EOM cause the reduction of coagulation effciency. In contrast, proteins in COM were obtained as possible inhibitory substances for the coagulation with PACl. These proteins could consume PACl in the coagulation process due to the formation of chelate complexes between these inhibitory proteins and the coagulant. The consumption of PACl by cyanobacterial proteins could be one of the important causes of the increase in coagulant demand.
authors.affiliation: Department of Civil Engineering, Graduate School of Engineering, Tohoku University, Aoba 6-6-06, Sendai 980-8579, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Takaara
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sano
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Konno
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Omura
mesh_terms: D000536:Aluminum Hydroxide / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry*; D005427:Flocculation; D046931:Microcystis; D018508:Water Purification
chemical_list: D001426:Bacterial Proteins; C016213:aluminum oxychloride; D000536:Aluminum Hydroxide