Evidence for adaptation of riverine sediment microbial communities to diuron mineralization: incidence of runoff and soil erosion

Abstract

Purpose Surface runoff and erosion are major drivers of pesticide transport from soils to rivers draining vineyard watersheds. A recent study showed that applications of diuron on vineyards and diuron dispersal could lead to microbial adaptation to diuron biodegradation from treated soils to the receiving hydrosystem. Given the limited knowledge on microbial adaptation to pesticide degradation in aquatic environments, we conducted a microcosm study designed to assess the impact of runoff and erosion processes on the adaptation of riverine-sediment microbial communities to diuron mineralization. Materials and methods The experimental laboratory set-up consisted in aquariums filled with natural riverine sediments and water and supplemented or not in triplicate (a) with diuron to simulate surface water runoff and (b) with diuron-treated vineyard soil to simulate erosion following a strong rainfall event. The resulting effects were estimated by assessing and comparing (a) the fate of diuron and diuron partitioning between sediment and water phases, (b)

A high-throughput sequencing ecotoxicology study of freshwater bacterial communities and their responses to tebuconazole

“…A typical example is the Alphaproteobacteria phylum, which was recovered in similar proportions from lakes and rivers, but was dominated by different clusters: the LD12 cluster and GOBB3-C201 for lakes and rivers, respectively (Gl€ ockner et al, 2000;Zwart et al, 2002;Debroas et al, 2009). This clade is assigned to an uncultured rape rhizosphere bacterium, which confirms the close relationships between the bacterial community from the River Morcille and that from the soil of the river bank, as had already been suggested by Pesce et al (2010). This clade is assigned to an uncultured rape rhizosphere bacterium, which confirms the close relationships between the bacterial community from the River Morcille and that from the soil of the river bank, as had already been suggested by Pesce et al (2010).…”

Freshwater sediment pesticide biodegradation potential as an ecological indicator of microbial recovery following a decrease in chronic pesticide exposure: A case study with the herbicide diuron

“…In addition, and interestingly, the mineralization kinetics obtained with upstream sediments in this study (Fig. 3) were quite similar to those obtained, following the same protocol, with sediments collected in June 2007 (Pesce et al, 2009) and February 2008(Pesce et al, 2010b at the same sampling site. This temporal stability over seasons and years further strengthens the reproducibility of the observations reported here, and justifies the use of the upstream sediments as reference in the present study.…”

“…Diuron 10% dissipation time (DT10) was estimated by fitting a log-normal regression model onto diuron mineralization kinetics (Pesce et al, 2010b). A three-way analysis of variance (ANOVA) was used to assess differences in DT10 and mineralization percentage after 15 weeks of incubation (MP15) between stations, years and seasons.…”

“…It has been shown that the development of pesticide biodegradation capacities in natural microbial communities, in both soils (e.g. Sørensen et al, 2003, Dellamatrice and Monteiro, 2004and El-Sebai et al, 2005; for phenylurea herbicides) and sediments (Toräng et al, 2003, Pesce et al, 2010band Trinh et al, 2012 occurs in response to repeated exposure to pesticide. The stable, low mineralization potential observed upstream thus clearly reflected the steady low level of diuron exposure recorded in this river section during the four-year survey period.…”

Environmental Metabolic Footprinting: A novel application to study the impact of a natural and a synthetic β-triketone herbicide in soil

“…Such results are commonly limited to a specific point in time and make estimating the global contamination of a sample extremely difficult. Today, several microbial ecotoxicology methodologies are emerging for the characterization of ecosystem contamination in soil, freshwater sediments and water samples (Ghiglione et al, 2014(Ghiglione et al, , 2016Joly et al, 2012Joly et al, , 2013Merlin et al, 2014Merlin et al, , 2015Pesce et al, 2010Pesce et al, , 2013. Even with these advances, the development and application of new methodologies for detecting pesticides and their transformation products in soil remains a challenge because of the extremely low concentration of the analytes, their wide range of polarities, strong soil binding affinity, and the inherent complex blend of transformation products in soils (Andreu and Pico, 2004).…”