Characterization of Bacterial and Archaeal Communities by DGGE and Next Generation Sequencing (NGS) of Nitrification Bioreactors Using Two Different Intermediate Landfill Leachates as Ammonium Substrate

Abstract Nitrification–denitrification is an environmentally friendly and cost-effective way to treat landfill leachates. Special attention has been given the nitrification step, usually limiting one due its special sensitivity environmental factors. Here, effect of acclimatization nitrifying biomass two different intermediate leachates with salt concentrations, COD BOD 5 studied. Despite complete being successfully performed, specific nitritation rates were reduced after adaptation both caused by presence heavy metals high concentration. NGS analysis samples revealed that Proteobacteria (48.5%), Actinobacteriota (14.4%) Chloroflexi (9.5%) dominant phyla in non-adapted biomass. The leachate feeding led a decrease OTU diversity favored growth Bacteroidetes (27.2%), Euryarchaeota (26.6%) (20.0%) accounting for more than 70% relative abundance. Several OTUs capable performing belong Xanthobacteraceae Xanthomonadaceae families, Saccharimonadales order, genus Nitrosomonas , Nitrosospira Paracoccus . In nitratation process, family Lautropia Nitrolancea genera found. Graphical