title: Bacterial Diversity in Bentonites, Engineered Barrier for Deep Geological Disposal of Radioactive Wastes.
abstract: The long-term disposal of radioactive wastes in a deep geological repository is the accepted international solution for the treatment and management of these special residues. The microbial community of the selected host rocks and engineered barriers for the deep geological repository may affect the performance and the safety of the radioactive waste disposal. In this work, the bacterial population of bentonite formations of Almeria (Spain), selected as a reference material for bentonite-engineered barriers in the disposal of radioactive wastes, was studied. 16S ribosomal RNA (rRNA) gene-based approaches were used to study the bacterial community of the bentonite samples by traditional clone libraries and Illumina sequencing. Using both techniques, the bacterial diversity analysis revealed similar results, with phylotypes belonging to 14 different bacterial phyla: Acidobacteria, Actinobacteria, Armatimonadetes, Bacteroidetes, Chloroflexi, Cyanobacteria, Deinococcus-Thermus, Firmicutes, Gemmatimonadetes, Planctomycetes, Proteobacteria, Nitrospirae, Verrucomicrobia and an unknown phylum. The dominant groups of the community were represented by Proteobacteria and Bacteroidetes. A high diversity was found in three of the studied samples. However, two samples were less diverse and dominated by Betaproteobacteria.
authors.affiliation: Department of Microbiology, University of Granada, Granada, Spain. margaritalopez@ugr.es.
authors.forename: Margarita
authors.initials: M
authors.lastname: Lopez-Fernandez
authors.affiliation: Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, Bautzner Landstrasse 400, 01328, Dresden, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Cherkouk
authors.affiliation: Laboratory of Microbial Ecology and Technology, Ghent University, Ghent, Belgium.
authors.forename: Ramiro
authors.initials: R
authors.lastname: Vilchez-Vargas
authors.affiliation: Helmholtz Centre for Infection Research, Braunschweig, Germany.
authors.forename: Ruy
authors.initials: R
authors.lastname: Jauregui
authors.affiliation: Helmholtz Centre for Infection Research, Braunschweig, Germany.
authors.forename: Dietmar
authors.initials: D
authors.lastname: Pieper
authors.affiliation: Laboratory of Microbial Ecology and Technology, Ghent University, Ghent, Belgium.
authors.forename: Nico
authors.initials: N
authors.lastname: Boon
authors.affiliation: Department of Microbiology, University of Granada, Granada, Spain.
authors.forename: Ivan
authors.initials: I
authors.lastname: Sanchez-Castro
authors.affiliation: Department of Microbiology, University of Granada, Granada, Spain.
authors.forename: Mohamed L
authors.initials: ML
authors.lastname: Merroun
mesh_terms: D001107:Architectural Accessibility; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D001546:Bentonite / Q000032:analysis*; D044822:Biodiversity; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D011850:Radioactive Waste; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D012990:Soil Pollutants, Radioactive / Q000032:analysis; D013030:Spain
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D011850:Radioactive Waste; D012990:Soil Pollutants, Radioactive; D001546:Bentonite
keywords: Bacterial diversity; Cloning and sequencing; Illumina sequencing; Spanish bentonite