Experimental procedures for studying microbial reactions under high hydrogen gas saturations in microcosms

This methodology is proposed to investigate the response of microbial communities through analysis of headspace composition under high saturations of hydrogen. Changes in headspace composition will be related to specific communities and environmental conditions that will influence their response and result in changes in gases produced or potential changes in the liquid phase of microcosms pertaining to the hydrogen consumption rate through microbial metabolic processes. A step-by-step procedure is documented here.•Methodology includes an easy setup utilising common laboratory equipment.•The method showed minor appreciable loss of hydrogen from the microcosm setup/storage and the use of exetainers for gas measurements.•Actively studied microbial hydrogen consumption across 18 days at 30 °C and 50 °C This method is useful for the first instances in scientific studies towards understanding species or microbial communities found in environments with high percentages of hydrogen: underground hydrogen storage sites, hydrogen pipelines, and hydrogen leakage into subsurface soils.