Experimental simulation of H coinjection via a high-pressure reactor with natural gas in a low-salinity deep aquifer used for current underground gas storage.

If dihydrogen (H) becomes a major part of the energy mix, massive storage in underground gas storage (UGS), such as in deep aquifers, will be needed. The development of H requires a growing share of H in natural gas (and its current infrastructure), which is expected to reach approximately 2% in Europe. The impact of H in aquifers is uncertain, mainly because its behavior is site dependent.

Assessment of the in situ biomethanation potential of a deep aquifer used for natural gas storage.

The dihydrogen (H2) sector is undergoing development and will require massive storage solutions. To minimize costs, the conversion of underground geological storage sites, such as deep aquifers, used for natural gas storage into future underground hydrogen storage sites is the favored scenario. However, these sites contain microorganisms capable of consuming H2, mainly sulfate reducers and methanogens.

A deep continental aquifer downhole sampler for microbiological studies.

To be effective, microbiological studies of deep aquifers must be free from surface microbial contaminants and from infrastructures allowing access to formation water (wellheads, well completions). Many microbiological studies are based on water samples obtained after rinsing a well without guaranteeing the absence of contaminants from the biofilm development in the pipes. The protocol described in this paper presents the adaptation, preparation, sterilization and deployment of a commercial downhole sampler (PDSshort, Leutert, Germany) for the microbiological studying of deep aquifers.

Microbial Diversity Under the Influence of Natural Gas Storage in a Deep Aquifer.

Deep aquifers (up to 2km deep) contain massive volumes of water harboring large and diverse microbial communities at high pressure. Aquifers are home to microbial ecosystems that participate in physicochemical balances. These microorganisms can positively or negatively interfere with subsurface (i) energy storage (CH and H), (ii) CO sequestration; and (iii) resource (water, rare metals) exploitation.

Biological, geological and chemical effects of oxygen injection in underground gas storage aquifers in the setting of biomethane deployment.

The last few years have seen the proliferation of anaerobic digestion plants to produce biomethane. Oxygen (O) traces added to biogas during the desulfurization process are co-injected in the gas network and can be stored in Underground Gas Storage (UGS). However, there are no data available for the undesirable effects of O on these anoxic environments, especially on deep aquifers.

Geological gas-storage shapes deep life.

Around the world, several dozen deep sedimentary aquifers are being used for storage of natural gas. Ad hoc studies of the microbial ecology of some of them have suggested that sulfate reducing and methanogenic microorganisms play a key role in how these aquifers' communities function. Here, we investigate the influence of gas storage on these two metabolic groups by using high-throughput sequencing and show the importance of sulfate-reducing Desulfotomaculum and a new monophyletic methanogenic group.

Pseudodesulfovibrio hydrargyri sp. nov., a mercury-methylating bacterium isolated from a brackish sediment.

The strain BerOc1 was isolated from brackish sediments contaminated with hydrocarbons and heavy metals. This strain has been used as a model strain of sulfate-reducer to study the biomethylation of mercury. The cells are vibrio-shaped, motile and not sporulated.

Desulfobulbus oligotrophicus sp. nov., a sulfate-reducing and propionate-oxidizing bacterium isolated from a municipal anaerobic sewage sludge digester.

A novel, mesophilic, strictly anaerobic, sulfate-reducing and propionate-oxidizing bacterium, strain Prop6T, was enriched and isolated from a municipal anaerobic sewage sludge digester. Cells were Gram-stain-negative, catalase-positive, oval rods, motile by means of amphitrichous flagella, non-spore-forming and contained menaquinone MK-5(H2) as the major respiratory quinone. The genomic DNA G+C content was 51.

The sequence capture by hybridization: a new approach for revealing the potential of mono-aromatic hydrocarbons bioattenuation in a deep oligotrophic aquifer.

The formation water of a deep aquifer (853 m of depth) used for geological storage of natural gas was sampled to assess the mono-aromatic hydrocarbons attenuation potential of the indigenous microbiota. The study of bacterial diversity suggests that Firmicutes and, in particular, sulphate-reducing bacteria (Peptococcaceae) predominate in this microbial community. The capacity of the microbial community to biodegrade toluene and m- and p-xylenes was demonstrated using a culture-based approach after several hundred days of incubation.