On the effect of Fe(III) on proliferation of Microcystis aeruginosa at high nitrate and low chlorophyll condition

Rong Chen; Zhen Lei; Jiayuan Ji; Xiaochang Wang; Yu-You Li; Yuan Yang; Lu Zhang; Tao Xue

doi:10.1016/j.jes.2016.03.006

On the effect of Fe(III) on proliferation of Microcystis aeruginosa at high nitrate and low chlorophyll condition

J Environ Sci (China). 2017 Feb:52:105-110. doi: 10.1016/j.jes.2016.03.006. Epub 2016 Apr 3.

Authors

Rong Chen¹, Zhen Lei², Jiayuan Ji³, Xiaochang Wang⁴, Yu-You Li³, Yuan Yang², Lu Zhang², Tao Xue²

Affiliations

¹ 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.
² Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China.
³ Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan.
⁴ 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.

PMID: 28254028
DOI: 10.1016/j.jes.2016.03.006

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 C_7-7.5H₁₄O_0.8-1.3N_3.5-5 according 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.

Keywords: Cell chlorophyll a; Fe; High nitrate; Low chlorophyll; Microcystis aeruginosa; Organic element composition.

MeSH terms

Chlorophyll / metabolism
Iron / metabolism*
Microcystis / physiology*
Nitrates / metabolism*
Photosynthesis / physiology*

Substances

Nitrates
Chlorophyll
Iron