Effects of benzophenone-3 on the green alga Chlamydomonas reinhardtii and the cyanobacterium Microcystis aeruginosa

Aquat Toxicol. 2017 Dec;193:1-8. doi: 10.1016/j.aquatox.2017.09.029. Epub 2017 Oct 2.

Abstract

Effects of benzophenone-3 (BP-3) on the green alga, Chlamydomonas reinhardtii, and the cyanobacterium, Microcystis aeruginosa, were investigated. The tested organisms were exposed to environmental levels of BP-3 for 10 days, at nominal concentrations from 0.01 to 5000μgL-1. Specific growth rate and photosynthetic pigments were employed to evaluate the toxic responses. The two tested algae had distinct toxic responses towards BP-3 stress, with the green alga C. reinhardtii being more sensitive than the cyanobacterium M. aeriginosa, based on EC20 and EC50 values. Uptake of BP-3 from the medium occurred in both species, with M. aeruginosa showing greater overall uptake (27.2-77.4%) compared to C. reinhardtii (1.1-58.4%). The effects of BP-3 on C. reinhardtii were variable at concentrations lower than 100μgL-1. At higher concentrations, the specific growth rate of C. reinhardtii decreased following a reduction in chlorophyll a (chl-a) content. Further experiments showed that BP-3 regulated the growth of C. reinhardtii by affecting the production of chl-a, chlorophyll b and carotenoids. In M. aeruginosa, specific growth rate was only moderately affected by BP-3. Additionally, the production of chl-a was significantly inhibited over the different exposure concentrations, while the production of carotenoids was stimulated. These results indicate a potential detrimental effect on prokaryotes and eukaryotes and that the mechanism of action varies with species.

Keywords: Benzophenone-3; Cyanobacteria; Green algae; Photosynthesis; Toxicity; Uptake.

MeSH terms

  • Benzophenones / toxicity*
  • Chlamydomonas reinhardtii / chemistry
  • Chlamydomonas reinhardtii / drug effects*
  • Chlorophyll / analysis
  • Chlorophyll A
  • Microcystis / chemistry
  • Microcystis / drug effects*
  • Photosynthesis
  • Pigments, Biological / analysis
  • Sunscreening Agents / toxicity*
  • Water Pollutants, Chemical / toxicity*

Substances

  • Benzophenones
  • Pigments, Biological
  • Sunscreening Agents
  • Water Pollutants, Chemical
  • Chlorophyll
  • chlorophyll b
  • oxybenzone
  • Chlorophyll A