Deciphering indigenous bacteria in compacted bentonite through a novel and efficient DNA extraction method: Insights into biogeochemical processes within the Deep Geological Disposal of nuclear waste concept
| Autor: | Margarita Lopez-Fernandez, María Victoria Villar, Mohamed L. Merroun, Fadwa Jroundi, Alena Ševců, Inés Martín-Sánchez, Cristina Povedano-Priego, Rojina Shrestha, Roman Špánek, Mark Dopson |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Biogeochemical cycle
Microbial diversity Environmental Engineering Health Toxicology and Mutagenesis ved/biology.organism_classification_rank.species 0211 other engineering and technologies Compaction chemistry.chemical_element 02 engineering and technology 010501 environmental sciences Desulfuromonas 01 natural sciences Thiobacillus Sulfurimonas RNA Ribosomal 16S Protocol Environmental Chemistry Desulfosporosinus Sequencing Waste Management and Disposal DNA extraction 0105 earth and related environmental sciences 021110 strategic defence & security studies DGR biology Bacteria ved/biology biology.organism_classification Pollution Sulfur Anoxic waters chemistry Delftia Environmental chemistry Radioactive Waste Bentonite Clay |
| Zdroj: | Digibug. Repositorio Institucional de la Universidad de Granada instname Digibug: Repositorio Institucional de la Universidad de Granada Universidad de Granada (UGR) |
| Popis: | Compacted bentonites are one of the best sealing and backfilling clays considered for use in Deep Geological Repositories of radioactive wastes. However, an in-depth understanding of their behavior after placement in the repository is required, including if the activity of indigenous microorganisms affects safety conditions. Here we provide an optimized phenol:chloroform based protocol that facilitates higher DNA-yields when other methods failed. To demonstrate the efficiency of this method, DNA was extracted from acetate-treated bentonites compacted at 1.5 and 1.7 g/cm3 densities after 24 months anoxic incubation. Among the 16S rRNA gene sequences identified, those most similar to taxa mediating biogeochemical sulfur cycling included sulfur oxidizing (e.g., Thiobacillus, and Sulfurimonas) and sulfate reducing (e.g., Desulfuromonas and Desulfosporosinus) bacteria. In addition, iron-cycling populations included iron oxidizing (e.g., Thiobacillus and Rhodobacter) plus reducing taxa (e.g., Geobacillus). Genera described for their capacity to utilize acetate as a carbon source were also detected such as Delftia and Stenotrophomonas. Lastly, microscopic analyses revealed pores and cracks that could host nanobacteria or spores. This study highlights the potential role of microbial driven biogeochemical processes in compacted bentonites and the effect of high compaction on microbial diversity in Deep Geological Repositories. |
| Databáze: | OpenAIRE |
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