title: Characterizing cell surface of blooming Microcystis in Lake Taihu, China.
abstract: Microcystis occurs as colonies in the natural environment but disaggregates into single cells in laboratory cultures. In order to explore the mechanism of how Microcystis forms colonies, the zeta potentials of Microcystis cells from the laboratory and the field were studied, and the hydrophobicity of Microcystis colonies in different sizes was investigated in Lake Taihu. The incubation experiment indicated that the zeta potentials of Microcystis cells were affected by growth phase and species. The absolute values in exponential phase were lower than those in stationary phase, suggesting that the cells with rapid growth easily formed colonies due to more instability on the cell surface. The values of Microcystis aeruginosa were higher than those of Microcystis flos-aquae, which confirmed that M. aeruginosa prevailed in waters for a longer time and at a larger size compared with M. flos-aquae. In another aspect, the absolute zeta potentials of Microcystis spp. at pH 7.0 decreased from spring to autumn in the field; the values in spring were higher than those in summer, suggesting that a large-sized Microcystis colony would more easily form in summer. Additionally, differences in hydrophobicity exist among Microcystis colonies of various sizes. The surface hydrophobicity of colonies in the <20 μm size class was higher than that of larger colonies. This characteristic allowed small colonies to easily form large colonies to survive better. These results would be helpful to understand the mechanism of the bloom formation, especially the colony formation, in Microcystis.
authors.affiliation: Poyang Lake Research Center, Jiangxi Academy of Sciences, Nanchang 330096, Jiangxi, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, No. 73 East Beijing Road, Nanjing 210008, Jiangsu province, China E-mail: qinbq@niglas.ac.cn.
authors.forename: Lizhen
authors.initials: L
authors.lastname: Liu
authors.affiliation: Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang 330022, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, No. 73 East Beijing Road, Nanjing 210008, Jiangsu province, China E-mail: qinbq@niglas.ac.cn.
authors.forename: Boqiang
authors.initials: B
authors.lastname: Qin
authors.affiliation: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, No. 73 East Beijing Road, Nanjing 210008, Jiangsu province, China E-mail: qinbq@niglas.ac.cn.
authors.forename: Guangwei
authors.initials: G
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, No. 73 East Beijing Road, Nanjing 210008, Jiangsu province, China E-mail: qinbq@niglas.ac.cn.
authors.forename: Pan
authors.initials: P
authors.lastname: Wu
authors.affiliation: Poyang Lake Research Center, Jiangxi Academy of Sciences, Nanchang 330096, Jiangxi, China.
authors.forename: Yongming
authors.initials: Y
authors.lastname: Wu
mesh_terms: D002681:China; D005068:Eutrophication; D057927:Hydrophobic and Hydrophilic Interactions; D060106:Lakes; D046931:Microcystis / Q000737:chemistry / Q000166:cytology* / Q000254:growth & development; D012621:Seasons; D055672:Static Electricity