Biodegradation and toxicity of a maize herbicide mixture: mesotrione, nicosulfuron and S-metolachlor

Genomic analysis of the Bacillus megaterium Mes11: New insights into nitroreductase genes associated with the degradation of mesotrione

“…Furthermore, a previous study has demonstrated the mesotrione transformation capacity of the B. megaterium Mes11 strain in a multi-contamination context (Carles et al, 2018). Our results corroborated this capacity "in cellulo".…”

“…The analytical grade herbicides (Mesotrione, nicosulfuron, S-metolachlor (Pestanal) and the Tryptic Soy broth (TS) medium were purchased from Sigma Aldrich (France). The composition of Glucosemineral Salt Medium (GSM), pH 6.7, was previously reported by Carles et al (2018). The B. megaterium Mes11 genome sequences have been deposited in GenBank under accessing numbers: CP048883 to CP048892.…”

“…The herbicide concentrations were measured by HPLC as described previously by Carles et al (2018). The mesotrione metabolites were identified and quantified by LC-MS and 1 H NMR, respectively, as previously described by Carles et al (2018).…”

“…Moreover, as mesotrione is usually applied agriculturally in mixture with the herbicides S-metolachlor (chloroacetanilide) and nicosulfuron (sulfonylurea) in order to improve its efficiency and the range of weeds treated, a focus was made on the impact of such mixtures on the nitroreductase expression. We have already shown that when mixed, any of these herbicides could have an impact on their individual toxicity and on the transformation kinetics of the others (Carles et al, 2018;Joly et al, 2013). In this manuscript, the physiological activity of the various nitroreductases found in B. megaterium to be involved in mesotrione-transformation was determined under multicontamination conditions to account for agricultural mixture exposure more realistically.…”

Carryover of tembotrione and atrazine in sugar beet

“…The combined application of two or more herbicides may alter the efficiency of one of the molecules, either by additive, synergistic or antagonistic effects (Charles et al, 2018). Additive and synergistic effects have been reported for different mixtures of herbicides, for example, the combination of atrazine + diuron (Wilkinson et al, 2015), mesotrione + s-metolachlor (Carles et al, 2018), and atrazine + butachlor (Chen et al, 2015). However, other studies have shown antagonistic effects for glyphosate + cloransulam-methyl (Harre et al, 2018).…”