WP3-HyLife

The goal of this WP3 is to characterize and evaluate the effect of microbial communities on H2 storage. WP3 propose an original approach from field sites to the laboratory (with experimental tests and analyses) based method alignment (WP2) followed by experimental investigation of the obtained field samples. The DNA based data will be used for direct modelling achievements, leading to the construction of a standard kinetic.

BRGM will manage all the tasks in WP3 with input from the leading institution in each task.

WP3 is orgonized in 2 subtasks :

• Experimental testing and study of microbial activity (BRGM)
• Bioinformatics and modelling of minimal microbial communities (INRIA)

We will first evaluate the impact of microbial communities on H2 storage, the initial status of each reservoir (i.e., baseline) will be analyzed in terms of microbial and geochemical aspects, according to methodology (WP2) and consequently applied during sample collection. • Chemical analysis of the brine/fluid samples. • DNA based characterization of the original brine/liquid samples. DNA will be extracted, amplified if necessary and sequenced..

• We then will analyze brine that will be used for laboratory enrichments with H2 and H2/gas mixtures to promote and identify microorganisms able to consume H2. We will characterize the microbial consortium activity (considering the H2 consumption) at laboratory scale by testing several experimental conditions (temperature, nutrient addition, H2 gas mixtures) to reproduce the H2 storage process.

• To answer key research questions, we will perform detailed studies of microbial H2 consuming activity with at least one-two enriched sample taken from each type of reservoir (salt cavern, aquifer, and depleted reservoir). These experiments will be planned with persons involved in biomodelling and mitigation to answer to specific needs constraining initial experimental conditions. Here we also want to test the influence of H₂ isotopic fractionation on selected enrichments to understand the potential use of this method for monitoring purposes.

In the bioinformatics subtask, we will provide a map: bioinformatics analysis to map community DNA data to metabolic functions through metabolic network reconstruction for each environmental sample.

We will also do a construction of simple kinetic models describing the minimal communities for different storage sites. Finally, analysis of diversity of metabolic functions and corresponding models across different storage sites to relate the composition of the microbial community in each site, its associated functional capabilities and resulting microbial impact. Correlation of composition with geological/physical/chemical parameters characterizing each site.