Affiliation:
1. Faculty of Nuclear Sciences and Physical Engineering, Department of Nuclear Chemistry Czech Technical University in Prague Prague Czech Republic
2. Radiochemistry Unit, Faculty of Science, Department of Chemistry University of Helsinki Helsinki Finland
3. School of Science and Technology, EnForce, Environment and Health and Systems Medicine Örebro University Örebro Sweden
4. VTT Technical Research Centre of Finland Espoo Finland
Abstract
AbstractThe deep terrestrial subsurface (DTS) harbours a striking diversity of microorganisms. However, systematic research on microbial metabolism, and how varying groundwater composition affects the bacterial communities and metabolites in these environments is lacking. In this study, DTS groundwater bacterial consortia from two Fennoscandian Shield sites were enriched and studied. We found that the enriched communities from the two sites consisted of distinct bacterial taxa, and alterations in the growth medium composition induced changes in cell counts. The lack of an exogenous organic carbon source (ECS) caused a notable increase in lipid metabolism in one community, while in the other, carbon starvation resulted in low overall metabolism, suggesting a dormant state. ECS supplementation increased CO2 production and SO42− utilisation, suggesting activation of a dissimilatory sulphate reduction pathway and sulphate‐reducer‐dominated total metabolism. However, both communities shared common universal metabolic features, most probably involving pathways needed for the maintenance of cell homeostasis (e.g., mevalonic acid pathway). Collectively, our findings indicate that the most important metabolites related to microbial reactions under varying growth conditions in enriched DTS communities include, but are not limited to, those linked to cell homeostasis, osmoregulation, lipid biosynthesis and degradation, dissimilatory sulphate reduction and isoprenoid production.
Subject
Ecology, Evolution, Behavior and Systematics,Microbiology