|
|||||
|
|
Selection of aquatic microbiota exposed to the herbicides flufenacet and metazachlor |
|
| Authors: | Lishani Wijewardene Julia Anna Schwenker Meike Friedrichsen Ailina Jensen Franziska Löbel Tabea Austen Uta Ulrich Nicola Fohrer Corinna Bang Silvio Waschina Christina Susanne Hölzel |
| Affiliation: | 1. Faculty of Fisheries and Marine Sciences & Technology, Department of Limnology and Water Technology, University of Ruhuna, Matara, Sri Lanka Contribution: Data curation (equal), Formal analysis (equal), Methodology (equal), Visualization (equal), Writing - original draft (lead);2. Institute of Animal Breeding and Husbandry, Department for Animal Hygiene, Animal Health and Food Hygiene, Kiel University, Kiel, Germany;3. Institute of Animal Breeding and Husbandry, Department for Animal Hygiene, Animal Health and Food Hygiene, Kiel University, Kiel, Germany Contribution: Investigation (equal);4. Institute of Animal Breeding and Husbandry, Department for Animal Hygiene, Animal Health and Food Hygiene, Kiel University, Kiel, Germany Contribution: Formal analysis (equal), Investigation (equal);5. Institute for Natural Resource Conservation, Department of Hydrology and Water Resources Management, Kiel University, Kiel, Germany Contribution: Conceptualization (equal), Project administration (equal), Resources (equal), Writing - review & editing (equal);6. Institute for Natural Resource Conservation, Department of Hydrology and Water Resources Management, Kiel University, Kiel, Germany Contribution: Project administration (equal), Resources (equal), Writing - review & editing (equal);7. Institute of Clinical Molecular Biology, Kiel University, Kiel, Germany Contribution: Data curation (equal), Formal analysis (equal);8. Institute for Human Nutrition and Food Science, Department for Nutriinformatics, Kiel University, Kiel, Germany Contribution: Formal analysis (equal), Visualization (equal);9. Institute of Animal Breeding and Husbandry, Department for Animal Hygiene, Animal Health and Food Hygiene, Kiel University, Kiel, Germany Contribution: Conceptualization (equal), Project administration (equal), Resources (equal), Supervision (equal), Writing - original draft (equal), Writing - review & editing (lead) |
| Abstract: | Herbicides are important, ubiquitous environmental contaminants, but little is known about their interaction with bacterial aquatic communities. Here, we sampled a protected natural freshwater habitat and characterised its microbiome in interaction with herbicides. We evolved the freshwater microbiomes in a microcosm assay of exposure (28 days) to flufenacet and metazachlor at environmental concentrations of 0.5, 5 and 50 μg L−1. Inhibitory effects of herbicides were exemplarily assessed in cultured bacteria from the same pond (Pseudomonas alcaligenes, Paenibacillus amylolyticus and Microbacterium hominis). Findings were compared to long-term concentrations as provided by local authorities. Here, environmental concentrations reached up to 11 μg L−1 (flufenacet) and 76 μg L−1 (metazachlor). Bacteria were inhibited at minimum inhibitory concentrations far above these values; however, concentrations of 50 μg L−1 of flufenacet resulted in measurable growth impairment. While most herbicide-exposed microcosm assays did not differ from controls, Acidobacteria were selected at high environmental concentrations of herbicides. Alpha-diversity (e.g., taxonomic richness on phylum level) was reduced when aquatic microbiomes were exposed to 50 μg metazachlor or flufenacet. One environmental strain of P. alcaligenes showed resistance to high concentrations of flufenacet (50 g L−1). In total, this study reveals that ecologic imbalance due to herbicide use significantly impacts aquatic microbiomes. |
| Keywords: | |