title: Mechanism-specific and whole-organism ecotoxicity of mono-rhamnolipids.
abstract: Biosurfactants like rhamnolipids are promising alternatives to chemical surfactants in a range of applications. A wider use requires an analysis of their environmental fate and their ecotoxicological potential. In the present study mono-rhamnolipids produced by a recombinant Pseudomonas putida strain were analyzed using the Green Toxicology concept for acute and mechanism-specific toxicity in an ecotoxicological test battery. Acute toxicity tests with the invertebrate Daphnia magna and with zebrafish embryos (Danio rerio) were performed. In addition, microbial and fungicidal effectiveness was investigated. Mutagenicity of the sample was tested by means of the Ames fluctuation assay. A selected mono-rhamnolipid was used for model simulations regarding mutagenicity and estrogenic activity. Our results indicate that mono-rhamnolipids cause acute toxicity to daphnids and zebrafish embryos comparable to or even lower than chemical surfactants. Rhamnolipids showed very low toxicity to the germination of Aspergillus niger spores and the growth of Candida albicans. No frameshift mutation or base substitutions were observed using the Ames fluctuation assay with the two tester strains TA98 and TA100. This result was confirmed by model simulations. Likewise it was computed that rhamnolipids have no estrogenic potential. In conclusion, mono-rhamnolipids are an environmental friendly alternative to chemical surfactants as the ecotoxicological potential is low.
authors.affiliation: Department of Ecosystem Analysis, Inst. for Environmental Research (Biology V), Worringerweg 1, 52074 Aachen, Germany. Electronic address: sarah.johann@rwth-aachen.de.
authors.forename: Sarah
authors.initials: S
authors.lastname: Johann
authors.affiliation: Department of Ecosystem Analysis, Inst. for Environmental Research (Biology V), Worringerweg 1, 52074 Aachen, Germany.
authors.forename: Thomas-Benjamin
authors.initials: TB
authors.lastname: Seiler
authors.affiliation: Aachen Biology and Biotechnology - ABBt. Institute of Applied Microbiology iAMB, Worringerweg 1, 52074 Aachen, Germany.
authors.forename: Till
authors.initials: T
authors.lastname: Tiso
authors.affiliation: Department of Ecosystem Analysis, Inst. for Environmental Research (Biology V), Worringerweg 1, 52074 Aachen, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Bluhm
authors.affiliation: Aachen Biology and Biotechnology - ABBt. Institute of Applied Microbiology iAMB, Worringerweg 1, 52074 Aachen, Germany.
authors.forename: Lars M
authors.initials: LM
authors.lastname: Blank
authors.affiliation: Department of Ecosystem Analysis, Inst. for Environmental Research (Biology V), Worringerweg 1, 52074 Aachen, Germany. Electronic address: henner.hollert@bio5.rwth-aachen.de.
authors.forename: Henner
authors.initials: H
authors.lastname: Hollert
mesh_terms: D000818:Animals; D003621:Daphnia / Q000187:drug effects*; D003651:Decanoates / Q000633:toxicity; D054750:Ecotoxicology; D006017:Glycolipids / Q000633:toxicity*; D016958:Pseudomonas putida; D012210:Rhamnose / Q000031:analogs & derivatives / Q000633:toxicity; D013501:Surface-Active Agents / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D003651:Decanoates; D006017:Glycolipids; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; C418382:rhamnolipid; C085734:rhamnopyranosyl-3-hydroxydecanoyl-3-hydroxydecanoate; D012210:Rhamnose
keywords: Acute effects; Consumer safety; Green toxicology; Mechanism-specific effects; Mono-rhamnolipids; Surfactant