Editorial: Microbial Ecotoxicology Advances to Improve Environmental and Human Health Under Global Change

"Structural responses of non-targeted bacterial and hppd communities to the herbicide tembotrione in soil"

Tembotrione (TBT) is a β-triketone herbicide targeting the 4-Hydroxyphenylpyruvate dioxygenase enzyme (4-HPPD) of weeds. This molecule can also affect soil microorganisms, either through both direct and indirect toxic effects for microorganisms expressing 4-HPPD, or by promoting tolerant and/or degrading microbial populations. Our study aimed to characterize the impacts of TBT on the diversity of total- and hppd (coding for 4-HPPD) -soil bacterial communities. Soil microcosms were treated with the active ingredient TBT at the recommended field dose (100 g a.i/ha; D1) or the tenfold dose (D10). Soil samples were collected from 0 to 55 days post-treatment to study: (i) total- and hppd-bacterial diversities using 16SrRNA and hppd amplicons sequencing, respectively; (ii) TBT dissipation in soil. Both total- and hppd-bacterial community composition was not affected by TBT treatments (D1 and D10). However, D10 treatment slightly increased richness and phylogenetic diversity of the total bacterial community while decreasing hppd richness. Overall, the highest dose of TBT seemed to promote TBT-tolerant or TBT-degrading bacterial populations and to deplete TBT-sensitive ones. These effects were transient as TBT was rapidly dissipated with a DT50 of 7 days and 15 days for D1 and D10, respectively. Differential abundance analysis with a Generalized Linear Model allowed the identification of Sphingomonas, Steroidobacter and Lysobacter as genus that were influenced by TBT, and which could be used as a new class of exposure biomarkers.

Federating young researchers in microbial ecotoxicology: EcotoxicoMicYR 2021, the first international webinar organized for and by young microbial ecotoxicology researchers

The EcotoxicoMicYR group was initially composed of 4 Ph.D. students and 4 post-doctoral researchers. In brief, the EcotoxicoMicYR webinar took place three Monday afternoons in a row from November 22 to December 6, 2021. These three half-day webinars reached a success beyond our expectations with 25 countries and 41 presentations. Keynote lectures were delivered by Dr Fabio Roldan (Pontificia Universidad Javeriana, Colombia), Dr Belinda Ferrari (The University of New South Wales, Australia), and Dr Ahmed Tlili (Eawag, Switzerland). Their presentations provided an insight on latest research developments in the microbial ecotoxicology field and highlighted their specific contribution to this discipline. Twenty-two oral presentations and 16 pre-recorded presentations were diffused.