RT journal article T1 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 A1 González Cortés, José Joaquín A1 Valle Gallardo, Antonio A1 Ramírez Muñoz, Martín A1 Cantero Moreno, Domingo A2 BiomedicinaBiotecnología y Salud Pública A2 Ingeniería Química y Tecnología de Alimentos K1 Nitrification K1 Landfill leachate K1 Denaturing gradient gel electrophoresis (DGGE) K1 Next generation sequencing (NGS) AB Nitrification-denitrification is an environmentally friendly and cost-effective way to treat landfill leachates. Special attention has been given to the nitrification step, usually the limiting one due to its special sensitivity to environmental factors. Here, the effect of the acclimatization of the nitrifying biomass to two different intermediate landfill leachates with different salt concentrations, COD and BOD5 has been studied. Despite the complete nitrification being successfully performed, the specific nitritation rates were reduced after the biomass adaptation to both landfill leachates caused by the presence of heavy metals and the high salt concentration. NGS analysis of the biomass samples revealed that Proteobacteria (48.5%), Actinobacteriota (14.4%) and Chloroflexi (9.5%) were the dominant phyla in the non-adapted biomass. The leachate feeding led to a decrease in OTU diversity and favored the growth of the phyla Bacteroidetes (27.2%), Euryarchaeota (26.6%) and Proteobacteria (20.0%) accounting for more than 70% of relative abundance. Several OTUs capable of performing the nitritation belong to the Xanthobacteraceae and the Xanthomonadaceae families, the Saccharimonadales order, and the genus Nitrosomonas, Nitrosospira and Paracoccus. In the nitratation process, the Xanthobacteraceae family and Lautropia and Nitrolancea genera were found. PB SPRINGER SN 1877-2641 YR 2022 FD 2022 LK http://hdl.handle.net/10498/26689 UL http://hdl.handle.net/10498/26689 LA eng NO Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. The Spanish Government (Ministry of Economy and Competitiveness) and the Vice-rectorate for Research of the University of Cadiz provided financial support through the project CTM2016-79089-R "Enhancement of landfill gas by an integrated biological system (Biointegra3)" and UCA/REC01VI/2017 (Universidad de Cadiz) respectively DS Repositorio Institucional de la Universidad de Cádiz RD 08-nov-2026