Toxicity of ciprofloxacin and sulfamethoxazole to marine periphytic algae and bacteria
- Published
- Accepted
- Subject Areas
- Ecotoxicology, Environmental Sciences, Marine Biology, Toxicology
- Keywords
- Microbial biofilms, Periphyton, Sulfamethoxazole, Antibiotics, Ciprofloxacin
- Copyright
- © 2014 Johansson et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ PrePrints) and either DOI or URL of the article must be cited.
- Cite this article
- 2014. Toxicity of ciprofloxacin and sulfamethoxazole to marine periphytic algae and bacteria. PeerJ PrePrints 2:e330v1 https://doi.org/10.7287/peerj.preprints.330v1
Abstract
Ciprofloxacin and sulfamethoxazole are two antibiotics commonly detected in the aquatic environment, but information on their toxicity towards natural microbial communities is largely absent. In particular no data are available for marine microorganisms. Aim of the current study was therefore to evaluate the chronic toxicity of ciprofloxacin and sulfamethoxazole on natural marine biofilms (periphyton), a complex ecological community comprising a variety of bacterial and algal species. The biofilms were sampled along the Swedish west coast and subsequently exposed over 4 days in a semi-static system to a concentration series of each antibiotic. Effects on the bacterial part of the periphyton community were assessed using Biolog Ecoplates, reflecting total respiration and functional diversity of the bacterial community. Exposure to either antibiotic resulted in a clear concentration-response relationship with EC10 and EC50 values for the inhibition of total carbon source utilization of 46.1 nmol/L and 490.7 nmol/L for ciprofloxacin, respectively 56 and 1073 nmol/L for sulfamethoxazole. The NOEC for ciprofloxacin was 26 nmol/L, with a minimum significant difference of 19.24%, for sulfamethoxazole it was 140 nmol/L with a minimum significant difference of 14%. Multivariate data exploration of the whole carbon source utilization pattern confirmed these results. The data indicate that sulfamethoxazole leads to a general decrease in carbon source utilization, while ciprofloxacin exposure leads to a re-arrangement of the carbon-utilization pattern in the region of 20-50% effect. This corresponds with the higher specificity of ciprofloxacin for certain bacterial species. Effects on the algal part of the communities were evaluated by analyzing the amount and composition of photosynthetic pigments, and neither ciprofloxacin nor sulfamethoxazole caused any inhibitory effects up to the maximum tested concentration of 9 000 nmol/L. However, sulfamethoxazole exposure did lead to a significant stimulation (75% above control level) of the total pigment content of the biofilm already at the lowest tested concentration of 5 nmol/L. The stimulation then decreased with increasing concentrations to finally return to control level at 3 000 nmol/L. No shifts in the relative pigment composition were observed, indicating a generally increased algal biomass without major shifts in community composition.
Author Comment
Manuscript submitted to peer-reviewed journal
Supplemental Information
Appendix 1 - Rawdata from Biolog Ecoplates
Data on periphytic bacteria exposed to ciprofloxacin and sulfamethoxazole respectively after incubation in Biolog Ecoplates
Appendix 2 - Classification of carbon sources in Biolog Ecoplates
Classification of the 31 carbon sources present on a Biolog Ecoplate.
Appendix 3 - Inhibition of AUC for the carbon sources active in the controls
Inhibition of are under the curve (AUC) for development over time for carbon source active in the controls.
Appendix 4 - Inhibition of total and individual pigments
The inhibtion of total and individual pigments after exposure to ciprofloxacin and sulfamethoxazole respectively.