Interaction between glyphosate and dissolved phosphorus on bacterial and eukaryotic communities from river biofilms

Abstract

Since the capacity of river biofilms to degrade glyphosate has been proven to increase when the availability of dissolved phosphorus (P) in water decreases, the present study investigates the diversity responses of bacterial and eukaryotic microbial communities from biofilms in a search for glyphosate-degrader candidates. Glyphosate and P interactions were observed for eukaryotic communities, the highest community richness and diversity being preserved at low concentrations of glyphosate and P. This trend marked by glyphosate was also observed in the structure of eukaryotic communities. Therefore, phosphorus and glyphosate had a synergistic effect in decreasing the richness and diversity of eukaryotes species in biofilms. However, species richness and diversity in bacterial communities were not affected by glyphosate, though shifts in the structure of these communities were concomitant with the degradation of the herbicide. Bacterial communities capable of using glyphosate as P source were characterized by increases in the relative abundance of certain Bacteroidetes, Chloroflexi, Cyanobacteria, Planctomycetes and alpha-Proteobacteria members. Glyphosate-degrader candidates found in natural river biofilms can be further isolated for better understanding of glyphosate degradation pathways, and used as bioremediation strategies in heavily contaminated sites.

Wastewater microorganisms impact microbial diversity and important ecological functions of stream periphyton

“…Cyanobacteria are known to respond differently (i.e. an increase or a decrease of abundance) to wastewater effluents (Carles et al, 2021;Carles and Artigas, 2020;Corcoll et al, 2014;Mansfeldt et al, 2020;Romero et al, 2019). However, we are not aware of any study that investigated the specific effect of wastewater microorganisms on this phylum.…”

Characterization of antibiotic resistance genes in drinking water sources of the Douhe Reservoir, Tangshan, northern China: the correlation with bacterial communities and environmental factors

“…In the Karst River (Guizhou), Proteobacteria, Bacteroidetes and Cyanobacteria were the most abundant bacterial phyla [16]. Most studies have shown that the Firmicutes, Proteobacteria, Bacteroidota, and Actinobacteriota were the dominant composition of the bacterial communities at the phylum level of rivers, reservoirs and domestic waste water in many regions of the world [21,28,[47][48][49]. At the genus level of the water samples of the Douhe Reservoir (Fig.…”

Twenty Years of Research in Ecosystem Functions in Aquatic Microbial Ecotoxicology

“…Dealing with glyphosate, for instance, Smedbol et al (2018) used environmentally realistic concentrations of the herbicide (from micrograms to milligrams of active ingredient per liter) and demonstrated a decrease in chlorophyll‐ a and carotenoid concentrations of phytoplankton communities from the lowest concentration of exposure. Opposite results were found by Pérez et al (2007) using higher concentrations of glyphosate: The primary production of phytoplankton exposed to milligrams of active ingredient per liter of glyphosate approximately doubled compared with control conditions, which could be related to increased phosphorus concentrations in the medium supplied by glyphosate additions (Saxton et al, 2011; but see Carles & Artigas, 2020). Such an increase in biomass (assessed as dry wt or chlorophyll‐ a concentration) was confirmed recently by Vera & Trinelli (2021) after a 7‐day exposure of periphyton to concentrations in the milligrams of active ingredient per liter of glyphosate.…”