title: Biodegradation of multiple microcystins and cylindrospermopsin in clarifier sludge and a drinking water source: Effects of particulate attached bacteria and phycocyanin.
abstract: The effects of particulate attached bacteria (PAB) and phycocyanin on the simultaneous biodegradation of a mixture of microcystin-LR, YR, LY, LW, LF and cylindrospermopsin (CYN) was assessed in clarifier sludge of a drinking water treatment plant (DWTP) and in a drinking water source. The biomass from lake water and clarifier sludge was able to degrade all microcystins (MCs) at initial concentrations of 10µgL(-1) with pseudo-first order reaction half-lives ranging from 2.3 to 8.8 days. CYN was degraded only in the sludge with a biodegradation rate of 1.0×10(-1)d(-1) and a half-life of 6.0 days. This is the first study reporting multiple MCs and CYN biodegradation in the coagulation-flocculation sludge of a DWTP. The removal of PAB from the lake water and the sludge prolonged the lag time substantially, such that no biodegradation of MCLY, LW and LF was observed within 24 days. Biodegradation rates were shown to increase in the presence of C-phycocyanin as a supplementary carbon source for indigenous bacteria, a cyanobacterial product that accompanies cyanotoxins during cyanobacteria blooms. MCs in mixtures degraded more slowly (or not at all) than if they were degraded individually, an important outcome as MCs in the environment are often present in mixtures. The results from this study showed that the majority of the bacterial biomass responsible for the biodegradation of cyanotoxins is associated with particles or biological flocs and there is a potential for extreme accumulation of cyanotoxins within the DWTP during a transient bloom.
authors.affiliation: Polytechnique de Montréal, Civil, Mineral and Mining Engineering Department, P.O. Box 6079, Station Centre- Ville, Montréal, Québec, Canada H3C 3A7. Electronic address: ehsan.maghsoudi@polymtl.ca.
authors.forename: Ehsan
authors.initials: E
authors.lastname: Maghsoudi
authors.affiliation: National Research Council Canada, Energy, Mining and Environment, 6100 Royalmount Ave., Montréal, QC, Canada H4P 2R2.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Fortin
authors.affiliation: National Research Council Canada, Energy, Mining and Environment, 6100 Royalmount Ave., Montréal, QC, Canada H4P 2R2.
authors.forename: Charles
authors.initials: C
authors.lastname: Greer
authors.affiliation: Department of Chemistry, Université de Montréal, C.P. 6128, Centre-Ville, Montréal, QC, Canada H3C 3J7.
authors.forename: Sung Vo
authors.initials: SV
authors.lastname: Duy
authors.affiliation: Department of Chemistry, Université de Montréal, C.P. 6128, Centre-Ville, Montréal, QC, Canada H3C 3J7.
authors.forename: Paul
authors.initials: P
authors.lastname: Fayad
authors.affiliation: Department of Chemistry, Université de Montréal, C.P. 6128, Centre-Ville, Montréal, QC, Canada H3C 3J7.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Sauvé
authors.affiliation: Polytechnique de Montréal, Civil, Mineral and Mining Engineering Department, P.O. Box 6079, Station Centre- Ville, Montréal, Québec, Canada H3C 3A7.
authors.forename: Michèle
authors.initials: M
authors.lastname: Prévost
authors.affiliation: Polytechnique de Montréal, Civil, Mineral and Mining Engineering Department, P.O. Box 6079, Station Centre- Ville, Montréal, Québec, Canada H3C 3A7.
authors.forename: Sarah
authors.initials: S
authors.lastname: Dorner
mesh_terms: D000470:Alkaloids; D001427:Bacterial Toxins; D001673:Biodegradation, Environmental; D018533:Biomass; D000458:Cyanobacteria / Q000378:metabolism*; D000087522:Cyanobacteria Toxins; D060766:Drinking Water / Q000737:chemistry* / Q000382:microbiology; D005427:Flocculation; D005618:Fresh Water; D006207:Half-Life; D060106:Lakes / Q000382:microbiology; D052998:Microcystins / Q000737:chemistry* / Q000633:toxicity; D010798:Phycocyanin / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology; D014498:Uracil / Q000031:analogs & derivatives* / Q000737:chemistry / Q000633:toxicity; D018508:Water Purification / Q000379:methods
chemical_list: D000470:Alkaloids; D001427:Bacterial Toxins; D000087522:Cyanobacteria Toxins; D060766:Drinking Water; D052998:Microcystins; D012722:Sewage; D010798:Phycocyanin; C089595:cylindrospermopsin; D014498:Uracil
keywords: Biodegradation; Clarifier sludge; Cylindrospermopsin; Microcystin; Phycocyanin; Sludge management