title: On the effect of Fe(III) on proliferation of Microcystis aeruginosa at high nitrate and low chlorophyll condition.
abstract: The impact of Fe concentrations on the growth of Microcystisaeruginosa in aquatic systems under high nitrate and low chlorophyll conditions was studied. The responses of cell density, total and cell chlorophyll-a intracellular Fe content and organic elemental composition of M. aeruginosa to different concentration gradients of Fe(III) in the solutions were analysed. The results showed that the proliferation speeds of M. aeruginosa were: (1) decelerated when the Fe(III) concentration was lower than 50μg/L in the solutions, (2) promoted and positively related to the increase of Fe(III) concentration from 100 to 500μg/L in the solutions over the experimental period, and (3) promoted in the early stage but decelerated in later stages by excess adsorption of Fe by cells when the Fe(III) concentration was higher than 500μg/L in the solutions. The maximum cell density, total and cell chlorophyll-a were all observed at 500μg Fe(III)/L concentration. The organic elemental composition of M. aeruginosa was also affected by the concentration of Fe(III) in the solutions, and the molecular formula of M. aeruginosa should be expressed as C7-7.5H14O0.8-1.3N3.5-5according to the functions for different Fe(III) concentrations. Cell carbon and oxygen content appeared to increase slightly, while cell nitrogen content appeared to decrease as Fe(III) concentrations increased from 100 to 500μg/L in the solutions. This was attributed to the competition of photosynthesis and nitrogen adsorption under varying cell Fe content.
authors.affiliation: Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China; Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan. Electronic address: chenrong@xauat.edu.cn.
authors.forename: Rong
authors.initials: R
authors.lastname: Chen
authors.affiliation: Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Lei
authors.affiliation: Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan.
authors.forename: Jiayuan
authors.initials: J
authors.lastname: Ji
authors.affiliation: Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China. Electronic address: xcwang@xauat.edu.cn.
authors.forename: Xiaochang
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan.
authors.forename: Yu-You
authors.initials: YY
authors.lastname: Li
authors.affiliation: Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Xue
mesh_terms: D002734:Chlorophyll / Q000378:metabolism; D007501:Iron / Q000378:metabolism*; D046931:Microcystis / Q000502:physiology*; D009566:Nitrates / Q000378:metabolism*; D010788:Photosynthesis / Q000502:physiology*
chemical_list: D009566:Nitrates; D002734:Chlorophyll; D007501:Iron
keywords: Cell chlorophyll a; Fe; High nitrate; Low chlorophyll; Microcystis aeruginosa; Organic element composition