Microalgal exposure to human antibiotics triggers similarities in growth and photosynthetic responses

Adeolu Olabode Aderemi*, Joanne Roberts, Colin Hunter, Ole Pahl

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

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The discharge of pharmaceuticals via wastewater into the environment is a great concern due to the constant threat posed to photosynthetic organisms since they are vital for the sustenance of the aquatic food web. To compare the photosynthetic and growth responses of green algae to human antibiotics, Raphidocelis subcapitata and Chlorella vulgaris were exposed to erythromycin and sulfamethoxazole for 96 h. A much higher sensitivity was shown by Raphidocelis to the antibiotics. Although erythromycin was more acutely toxic to photosynthesis (EC50, 24.6 μg/L; EC10, 14.6 μg/L) than growth (EC50, 160 μg/L; EC10, 27 μg/L) in Raphidocelis, chronic effects in terms of EC10 were alike. Interestingly, sulfamethoxazole exhibited similar toxicity towards growth and photosynthesis with the acute and chronic toxicity parameters for growth (EC50, >2000 μg/L; EC10, 260 μg/L for Raphidocelis; and EC50, 47,900 μg/L; EC10, 19,100 μg/L for Chlorella) in consonance with those of photosynthesis (EC50, >2000 μg/L; EC10, 340 μg/L for Raphidocelis; and EC50, 47,500 μg/L; EC10, 13,400 μg/L for Chlorella). Growth and photosynthesis in Raphidocelis were strongly inhibited in this study at environmentally relevant concentrations of erythromycin. The findings from this study demonstrated that photosynthetic yield was a reliable indicator of sulfamethoxazole and erythromycin effects and thus, may be useful as an alternative approach to growth in assessing chronic toxicity in antibiotics.
Original languageEnglish
Pages (from-to)509-525
Number of pages17
JournalJournal of Environmental Protection
Issue number8
Publication statusPublished - 10 Aug 2021


  • pharmaceuticals
  • antibiotics
  • toxicity
  • growth
  • photosynthesis
  • green algae

ASJC Scopus subject areas

  • General Biochemistry,Genetics and Molecular Biology


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