title: Immediate and long-term impacts of potassium permanganate on photosynthetic activity, survival and microcystin-LR release risk of Microcystis aeruginosa.
abstract: The immediate and long-term impacts of potassium permanganate (KMnO(4)) as pre-oxidant on Microcystis aeruginosa and microcystin-LR (MC-LR) release risk were investigated. The cell density and the integrity of M. aeruginosa were determined by a flow cytometry, and typical photosynthetic parameters were measured by a pulse amplitude modulated fluorometer. The photosynthetic parameters were reduced to different degrees, accompanied with slight cytoclasis and complete degradation of extracellular MC-LR immediately after various dosages KMnO(4) oxidation (2-20 mg L(-1)). In a 6-d cultivation following 5 mg L(-1) KMnO(4) oxidation, the cell density decreased from 3.9×10(6) to 0.6×10(6) cells mL(-1), and then increased to 0.9×10(6) cells mL(-1), while the extracellular MC-LR increased from 0 to 51.2 μg L(-1). In the cultivation after 10 mg L(-1) KMnO(4) treatment, the intracellular MC-LR and cell activity significantly declined, while significant cytoclasis (cell density from 3.8×10(6) to 0 cells mL(-1)) and MC-LR release (increase from 0 to 15.2 μg L(-1)) were observed. The photosynthetic parameters were found to be useful tools to predict the recovery tendency of M. aeruginosa cells, and the MC-LR release risk should be considered during KMnO(4) pre-oxidation in water-treatment plants.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China.
authors.forename: Huase
authors.initials: H
authors.lastname: Ou
authors.forename: Naiyun
authors.initials: N
authors.lastname: Gao
authors.forename: Chaohai
authors.initials: C
authors.lastname: Wei
authors.forename: Yang
authors.initials: Y
authors.lastname: Deng
authors.forename: Junlian
authors.initials: J
authors.lastname: Qiao
mesh_terms: D005434:Flow Cytometry; D008387:Marine Toxins; D052998:Microcystins / Q000378:metabolism*; D046931:Microcystis / Q000378:metabolism* / Q000502:physiology; D010084:Oxidation-Reduction; D010788:Photosynthesis / Q000187:drug effects*; D011196:Potassium Permanganate / Q000494:pharmacology*
chemical_list: D008387:Marine Toxins; D052998:Microcystins; D011196:Potassium Permanganate; C057862:cyanoginosin LR