Bacterial Diversity in Bentonites, Engineered Barrier for Deep Geological Disposal of Radioactive Wastes López Fernández, Margarita Cherkouk, Andrea Vilchez-Vargas, Ramiro Jauregui, Ruy Pieper, Dietmar Boon, Nico Sanchez-Castro, Ivan Merroun, Mohamed Larbi 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, Proteobact e r i a , N i t rospirae, 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. 2026-02-26T08:07:01Z 2026-02-26T08:07:01Z 2015-05-30 journal article Lopez-Fernandez, M., Cherkouk, A., Vilchez-Vargas, R., Jauregui. R., Pieper, D., Boon, N., Sanchez-Castro, I., Merroun, M.L. 2015. Bacterial Diversity in Bentonites, Engineered Barrier for Deep Geological Disposal of Radioactive Wastes. Microbial Ecology 70:922–935. DOI 10.1007/s00248-015-0630-7 https://hdl.handle.net/10481/111535 10.1007/s00248-015-0630-7 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ embargoed access Attribution-NonCommercial-NoDerivatives 4.0 Internacional