title: Simultaneous Microcystis Algicidal and Microcystin Degrading Capability by a Single Acinetobacter Bacterial Strain.
abstract: Measures for removal of toxic harmful algal blooms often cause lysis of algal cells and release of microcystins (MCs). In this study, Acinetobacter sp. CMDB-2 that exhibits distinct algal lysing activity and MCs degradation capability was isolated. The physiological response and morphological characteristics of toxin-producing Microcystis aeruginosa, the dynamics of intra- and extracellular MC-LR concentration were studied in an algal/bacterial cocultured system. The results demonstrated that Acinetobacter sp. CMDB-2 caused thorough decomposition of algal cells and impairment of photosynthesis within 24 h. Enhanced algal lysis and MC-LR release appeared with increasing bacterial density from 1 × 103to 1 × 107cells/mL; however, the MC-LR was reduced by nearly 94% within 14 h irrespective of bacterial density. Measurement of extracellular and intracellular MC-LR revealed that the toxin was decreased by 92% in bacterial cell incubated systems relative to control and bacterial cell-free filtrate systems. The results confirmed that the bacterial metabolite caused 92% lysis of Microcystis aeruginosa cells, whereas the bacterial cells were responsible for approximately 91% reduction of MC-LR. The joint efforts of the bacterium and its metabolite accomplished the sustainable removal of algae and MC-LR. This is the first report of a single bacterial strain that achieves these dual actions.
authors.affiliation: Key Laboratory of Eco-Environment of Three Gorges Region of Ministry of Education, Chongqing University , Chongqing 400044, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.affiliation: Key Laboratory of Eco-Environment of Three Gorges Region of Ministry of Education, Chongqing University , Chongqing 400044, China.
authors.forename: Hainan
authors.initials: H
authors.lastname: Ai
authors.affiliation: Key Laboratory of Eco-Environment of Three Gorges Region of Ministry of Education, Chongqing University , Chongqing 400044, China.
authors.forename: Li
authors.initials: L
authors.lastname: Kang
authors.affiliation: Xiamen Municipal Engineering Design Institute CO., LTD, Chongqing 401122, China.
authors.forename: Xingfu
authors.initials: X
authors.lastname: Sun
authors.affiliation: Key Laboratory of Eco-Environment of Three Gorges Region of Ministry of Education, Chongqing University , Chongqing 400044, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: He
mesh_terms: D000150:Acinetobacter / Q000378:metabolism; D057097:Harmful Algal Bloom; D052998:Microcystins / Q000378:metabolism*; D046931:Microcystis / Q000378:metabolism*; D010788:Photosynthesis
chemical_list: D052998:Microcystins