Selection of environmentally toxic aquatic microbial communities by bentazone herbicide pressure
- Ninane, V. , Aerts, C. , Gelhay, V. & Debode, F. (2022). Selection of environmentally toxic aquatic microbial communities by bentazone herbicide pressure. Poster in: 3rd International Conference in Microbial Ecotoxicology, Montpellier, France, 15-18 November 2022.
| Type | Poster |
| Year | 2022 |
| Title | Selection of environmentally toxic aquatic microbial communities by bentazone herbicide pressure |
| Event name | 3rd International Conference in Microbial Ecotoxicology |
| Event location | Montpellier, France |
| Event date | 15-18 November 2022 |
| Endnote keywords | Water, Herbicide contamination, Indirect side effect, Microbial algaecide |
| Abstract | We isolated microbial consortia from pond waters and rainwaters contaminated with bentazone herbicide at levels ranging from 0.48 g/L to 48 g/L, i.e. ten folds more or less than the dose applied in the field. We further tested four consortia for their potential toxicity against the freshwater green algae Raphidocelis subcapitata that play a very important role as primary producers in aquatic systems. For that, we incubated a basal culture broth, composed of tryptone (10 g/L) and salt (5 g/L), with the consortia, in the dark and for 11 days. After microbial incubation, we sterilized the culture broth by filtration through a filter of 0.2 µm pore size and added minerals and trace elements that act as growth factors by mixing the filtered broth with the Algaltoxkit F (Microbiotests, Gent, Belgium). Surprisingly, the culture broth incubated with the consortia drastically inhibited algal growth; in these culture broths, the algae grew from two to seven times less than the algae cultivated in the control broth, i.e. the basal culture broth maintained in the same conditions but without any microbial consortia. Three of the tested microbial consortia produced a more toxic broth for the algae than the control broth added with 4.8 g/L bentazone. The microbial composition of the consortia, determined by high-throughput sequencing of the 16S rDNA and ITS regions for bacteria and fungi respectively, revealed common environmental taxa: Pseudomonas, Clostridium, Providencia, Myroides and Comamonas for the more abundant bacterial genera present in all the consortia; Debaryomyces for the only fungal genus present in the four consortia. We showed that herbicide pressure on common aquatic microorganisms might lead to the production of a more toxic component for the aquatic plants than the herbicide itself. That was observed in a laboratory assay; what happens in nature? |
| Fichier | |
| Authors | Ninane, V., Aerts, C., Gelhay, V., Debode, F. |
Equipe
