Supplementary MaterialsData_Sheet_1. alluvial aquifer (Southwest of France). = 6 May 2012

Supplementary MaterialsData_Sheet_1. alluvial aquifer (Southwest of France). = 6 May 2012 C May 2013). In contrast, MET was not detected in well 224 (Supplementary Section D). Hydrochemical and bacterial composition of preliminary groundwater utilized for planning the direct exposure experiments was analyzed for evaluation with spiked and incubated groundwater. To evaluate the response of bacterial communities subjected to MET, groundwater subsamples (experimental repetitions) from initial 10 L groundwater samples gathered in each well, had been incubated in 1 L cup vials. Each vial included 700 mL of groundwater. Three exposition dosages were in comparison for every of both selected wells: history MET concentrations (no MET addition), and added MET at either 0.1 mg L-1 (equal to severe chronic contamination) or 5 mg L-1 (equal to punctual source contamination). An experimental repetition (i.electronic., two vials) was ready from each one of the two chosen wells and for each one of the three exposition dosages. The MET regular stock solution (1 g L-1 in can) was dissolved in distilled drinking water, and ACN was evaporated after 6 h stirring under a fume hood. MET aqueous solutions had been filter-sterilized through a 0.2 m syringe filter (Rotilabo?, Carl Roth?, France) just before spiking. To make sure initial homogeneisation pursuing spiking with MET, laboratory microcosms had been shaken at 100 rpm for 1 h before incubation at the same heat range of 20C. In experiments without MET addition, the same method was implemented using 100 % pure ACN evaporated in distilled drinking water to take into account possible ramifications of ACN traces. ACN was by no means detected in the headspace of MET aqueous solutions (data not really demonstrated). Control experiments (performed in duplicate) consisted in filter-sterilized water spiked with MET to evaluate abiotic MET dissipation. To keep up aerobic conditions while limiting BMS-354825 small molecule kinase inhibitor water loss and avoiding contamination, a 0.22 m syringe filter was mounted on a syringe tip stuck through the vial cap. Oxygen concentration in each microcosm was monitored weekly with oxygen sensor places (PreSens Precision Sensing GmbH, Germany) fixed to the inner face of the bottles before autoclaving. Oxygen concentrations from 5 to 8 mg L-1 confirmed oxic conditions throughout BMS-354825 small molecule kinase inhibitor the experiment (Supplementary Section C). Laboratory experiments with or without addition of MET were incubated for 21 days, a duration standard of reported MET half-life values (The Pesticide Properties DataBase [PPDB], 2006). Mean groundwater temp was 15 1.3C. Experiments were incubated at the reference temp for standardized screening of pesticides based on OECD recommendations of 20C (Organisation for Economic Co-operation and Development [OECD], 1981). Experiments were Kcnc2 incubated without stirring because (i) oxygen was constantly monitored and was not rate-limiting for bacterial growth (Hensler and Schedel, 1991), and (ii) stirring may artefactually alter the diversity of groundwater bacterial communities adapted to heterogeneous aquifer microenvironments and non-turbulent flows. At the end of incubations, water samples from each duplicate experiment were collected using sterile glass syringes for MET, TP analysis (2 15 mL) and the Microtox? assay (2 15 mL) (observe below). Remaining groundwater of each repetition experiment (2 670 mL) was filtered through a unique sterile 0.2 m cellulose membrane (Millipore, Billerica, MA, United States) to obtain DNA in adequate and representative quantities for Illumina sequencing (Aird et al., 2011). Each membrane was stored at -20C in sterile 50 mL plastic Falcon tubes until further processing. Chemical Analysis Hydrogeochemical Analysis Groundwater samples were analyzed at BRGM Orleans using ICP-AES (Ca2+, Na+, K+, Mg2+ with 5% uncertainty), ion chromatography (Cl-, SO42-, NO3- with 10% uncertainty) and potentiometric methods relating to N EN ISO 9963-1 (HCO3-, CO32- with 5% uncertainty). Total organic carbon (TOC) and dissolved organic carbon (DOC) were quantified relating to NF EN 1484 (1997) methods. Pesticide and TP Analysis of Field Samples Pesticides in groundwater, including MET and its neutral TP, were extracted using a Gilson GX 274 ASPEC solid phase extraction (SPE) system, with Oasis HLB (6 mL – 500 mg) cartridges (Waters) and quantified as explained elsewhere (Amalric et al., 2013). Briefly, cartridges were successively conditioned at pH 7 with 5 mL acetonitrile (ACN), 5 mL methanol (MeOH), and 5 mL deionized water (HPLC grade) at BMS-354825 small molecule kinase inhibitor a circulation rate of 1 1 mL min-1. Water samples (1 L) were loaded at a circulation rate of 5 mL min-1. After drying by flushing with genuine N2 (30 min), analytes were eluted twice successively with 4 mL ACN at a rate of 1 1 mL min-1. Sample extracts were concentrated down to.