In the majority of global marine sediments, microbes subsist either on organic matter that was buried long ago or on chemolithoautotrophic production. In non-advective sediments, which lack high fluxes of chemolithoautotrophic substrates, metabolism of ancient carbon is more important for sustaining subseafloor life. These microbial communities have very slow turnover times of at least decades, and are phylogenetically very distant from cultured organisms. Therefore, we have combined metagenomics, single cell genomics, geochemical measurements, 16S rRNA gene amplicon surveys, metatranscriptomics and metabolomics to identify strategies that allow them to subsist under such low energy conditions. We have identified multiple interactions between members of these microbial communities that likely enable them to survive while avoiding fast growth. Such strategies may include reversing metabolism to follow the direction that is energetically favorable, using trehalose and NAD-consuming deacetylation as preservative mechanisms, accessing unique carbon sources such as allantoin, and sharing metabolites in order to benefit multiple community members.
MARUM Research Seminar
MARUM I, room 2070