Publication Overview
Microorganisms are thought to be responsible for over half the biomass on the planet, with a substantial fraction of them in the subsurface. Some microorganisms are known to be able to exist in extreme conditions and have been found in the subsurface at depths greater than 3km and can therefore potentially exist at some locations considered for geological storage of CO2. In general the chemoautotrophic nature of subsurface ecosystems increases with depth, i.e. microbes in the deeper subsurface are more likely to be using CO2 to synthesise necessary organic compounds. Therefore these are what you may expect to find at the depth of a typical CO2 storage reservoir.
Publication Summary
There has been much work carried out on microbial activity in the subsurface, though there is limited information regarding the effect on CO2 storage. There are however, several research projects and studies underway looking into this topic.
CO2 can have a large effect on microbial activity, with the majority of microorganisms having a negative reaction to supercritical CO2.