Environmental changes microbial metabolism
Investigating the effect of environmental changes on microbial metabolism using oxygen isotopes in phosphate
Understanding how human activities and the concomitant use of resources and release of pollutants affect the state of the environment is of paramount importance to implement measures for maintaining ecosystem services. Ecosystem functioning in soils and water under anthropogenic impact including rising temperatures, water scarcity, and eutrophication, however, is difficult to define due to the challenges associated with assessing metabolic activity of the microbiome. Natural abundance 18O/16O ratios of phosphate, typically expressed as d18O(PO4), provide a possible indicator for a holistic assessment of the metabolic activity. Phosphoryl transfer reactions that govern formation and consumption of phosphate are essential in fundamental biological processes, including signaling, energy transduction, protein synthesis, and the transcription of genetic information. Systematic evaluations of d18O(PO4) in soils, for example, reveal that this indicator may reflect the averaged metabolic state of such environments beyond current interpretations based on the activity of a single class of phosphate-releasing enzymes (i.e., pyrophosphatases). The overall goal of the proposed research is to show how cytosolic d18O(PO4) relates to the metabolic activity of microorganisms in complex environments and thus serve as potential indicator for ecosystem functioning. To that end, we intend to provide the biochemical basis for evaluating d18O(PO4) systematically as responses to changes in phosphorus metabolism.
The FGCZ metabolomics team acts as a project partner within an interdisciplinary collaboration of Drs. Federica Tamburini (Institute of Agricultural Sciences, ETH Zürich) and Thomas Hofstetter (Environmental Chemistry, Eawag).