title: Triclosan causes toxic effects to algae in marine biofilms, but does not inhibit the metabolic activity of marine biofilm bacteria.
abstract: Effects of the antimicrobial agent triclosan to natural periphyton communities (biofilms, comprising primarily microalgae and bacteria) were assessed in two independent experiments during spring and summer. For that purpose a semi-static test system was used in which periphyton was exposed to a concentration range of 5-9054 nmol/L triclosan. Effects on algae were analyzed as content and composition of photosynthetic pigments. The corresponding EC50 values were 39.25 and 302.45 nmol/L for the spring and summer experiment, respectively. Effects on periphytic bacteria were assessed as effects on carbon utilization patterns, using Biolog Ecoplates. No inhibition of either total carbon utilization or functional diversity was observed, indicating a pronounced triclosan tolerance of the marine bacteria. In contrast, a small stimulation of the total carbon utilization was observed at triclosan concentrations exceeding 100 nmol/L.
authors.affiliation: University of Gothenburg, Department of Biological and Environmental Sciences, Sweden. Electronic address: henrik.johansson@bioenv.gu.se.
authors.forename: C Henrik
authors.initials: CH
authors.lastname: Johansson
authors.affiliation: University of Gothenburg, Department of Biological and Environmental Sciences, Sweden.
authors.forename: Lisa
authors.initials: L
authors.lastname: Janmar
authors.affiliation: University of Gothenburg, Department of Biological and Environmental Sciences, Sweden.
authors.forename: Thomas
authors.initials: T
authors.lastname: Backhaus
mesh_terms: D000891:Anti-Infective Agents, Local / Q000633:toxicity; D001419:Bacteria / Q000187:drug effects*; D018441:Biofilms / Q000187:drug effects*; D058086:Microalgae / Q000187:drug effects*; D014260:Triclosan / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D000891:Anti-Infective Agents, Local; D014874:Water Pollutants, Chemical; D014260:Triclosan
keywords: Algae; Bacteria; Microbial biofilms; Periphyton; Triclosan