Published on the Web 1/10/2008.
Growth-inhibiting effects of 12 antibacterial agents and their mixtures on the freshwater microalga Pseudokirchneriella subcapitata†
Article first published online: 9 DEC 2009
Copyright © 2008 SETAC
Environmental Toxicology and Chemistry
Volume 27, Issue 5, pages 1201–1208, May 2008
How to Cite
Yang, L.-H., Ying, G.-G., Su, H.-C., Stauber, J. L., Adams, M. S. and Binet, M. T. (2008), Growth-inhibiting effects of 12 antibacterial agents and their mixtures on the freshwater microalga Pseudokirchneriella subcapitata. Environmental Toxicology and Chemistry, 27: 1201–1208. doi: 10.1897/07-471.1
- Issue published online: 9 DEC 2009
- Article first published online: 9 DEC 2009
- Manuscript Accepted: 7 DEC 2007
- Manuscript Received: 6 DEC 2007
- Growth inhibition;
- Mixture effect
The growth-inhibiting and binary joint effects of 12 antibacterial agents on the freshwater green alga Pseudokirchneriella subcapitata (Korschikov) Hindák were investigated over 72-h exposures. The toxicity values (the median inhibitory concentration value, in micromoles) in decreasing order of sensitivity were triclosan (0.0018) > triclocarban (0.054) > roxithromycin (0.056) > clarithromycin (0.062) > tylosin (0.20) > tetracycline (2.25) > chlortetracycline (3.49) > norfloxacin (5.64) > sulfamethoxazole (7.50) > ciprofloxacin (20.22) > sulfamethazine (31.26) > trimethoprim (137.78). Several of these antibacterial compounds would be toxic at the micrograms per liter concentrations reported in surface waters and sewage effluents. Simple additive effects were observed in binary mixtures of sulfonamides, and most tylosin, triclosan, or triclocarban combinations. Potentially synergistic effects were observed in binary mixtures of the same class, such as macrolides, tetracyclines, and fluoroquinolones, as well as in some combined drugs, such as trimethoprim and sulfonamides or tylosin and tetracyclines. Potentially antagonistic effects were only observed between tylosin and triclocarban, triclosan and norfloxacin, and triclocarban and norfloxacin. Although present at low concentrations in the aquatic environment, mixtures of these antibacterial agents can potentially affect algal growth in freshwater systems due to their combined action.