Bacterial communities in batch and continuous-flow wetlands treating the herbicide S-metolachlor

摘要: Abstract Knowledge of wetland bacterial communities in the context pesticide contamination and hydrological regime is scarce. We investigated composition constructed wetlands receiving Mercantor Gold ® contaminated water (960 g L − 1 herbicide S -metolachlor, > 80% -enantiomer) operated under continuous-flow or batch modes to evaluate impact hydraulic regime. In wetland, -metolachlor mass removal was > 40%, whereas almost complete (93–97%) observed. Detection ethanesulfonic oxanilic acid degradation products further indicated biodegradation two wetlands. The dominant populations were characterised by terminal restriction fragment length polymorphism (T-RFLP) 454 pyrosequencing. profiles evolved during first 35 days experiment, starting from a similar that inlet water, with use nitrate lesser extent sulphate manganese as electron acceptors for microbial metabolism. Proteobacteria most abundant phylum, Beta -, Alpha - Gammaproteobacteria representing 26%, 19% 17% respectively total abundance. Bacterial changed gradually over time more abruptly wetland. Differences overall structure systems modest but significant ( p  = 0.008), nitrate, inorganic carbon concentrations correlated changes profiles. Together, results highlight their dynamics may be used bioindicators exposure disturbances systems.