Effects of different algaecides on the photosynthetic capacity, cell integrity and microcystin-LR release of Microcystis aeruginosa

Shiqing Zhou, Yisheng Shao, Naiyun Gao, Yang Deng, Junlian Qiao, Huase Ou, Jing Deng

Research output: Contribution to journalArticle

84 Scopus citations

Abstract

Bench scale tests were conducted to study the effects of four common algaecides, including copper sulfate, hydrogen peroxide, diuron and ethyl 2-methylacetoacetate (EMA) on the photosynthetic capacity, cell integrity and microcystin-LR (MC-LR) release of Microcystis aeruginosa. The release of potassium (K+) from cell membrane during algaecide exposure was also analyzed. The three typical photosynthetic parameters, including the effective quantum yield (Fe), photosynthetic efficiency (α) and maximal electron transport rate (rETRmax), were measured by a pulse amplitude modulated (PAM) fluorometry. Results showed that the photosynthetic capacity was all inhibited by the four algaecides, to different degrees, by limiting the energy capture in photosynthesis, and blocking the electron transfer chain in primary reaction. For example, at high diuron concentration (7.5mgL-1), Fe, α and rETRmax decreased from 0.46 to 0.19 (p<0.01), from 0.20 to 0.01 (p<0.01) μmol electrons m-2s-1/μmol photons m-2s-1, and from 160.7 to 0.1 (p<0.001) μmolm-2s-1 compared with the control group after 96h of exposure, respectively. Furthermore, the increase of algaecide dose could lead to the cell lysis, as well as release of intracellular MC-LR that enhanced the accumulation of extracellular MC-LR. The order of MC-LR release potential for the four algaecides was CuSO4>H2O2>diuron>EMA.

Original languageEnglish
Pages (from-to)111-119
Number of pages9
JournalScience of the Total Environment
Volume463-464
DOIs
StatePublished - 1 Oct 2013

Keywords

  • Cell lysis
  • Cyanobacteria
  • Microcystin-LR
  • PAM
  • Photosynthesis

Fingerprint Dive into the research topics of 'Effects of different algaecides on the photosynthetic capacity, cell integrity and microcystin-LR release of Microcystis aeruginosa'. Together they form a unique fingerprint.

  • Cite this