On geologic timescales, the anoxic degradation of organic carbon controls the redox chemistry of the Earth’s surface. Despite a myriad of - omics techniques, the microbial metabolisms that catalyze organic degradation remain unaccounted for in modern and ancient biogeochemical models. My works seeks to fill this gap. During my PhD, we’ve developed novel ultra-high resolution mass spectrometry (MS) techniques for isotope ratio measurements of excreted metabolites and quantitative modelling approaches for interpreting isotopic compositions in nature. The goal of these studies is to determine the relative importance of under-constrained metabolisms in the environment, including fermentation and autotrophic acetogenesis. Our experiments on pure cultures of diverse bacteria suggest that tandem analyses of compound-specific carbon (13C/12C) and hydrogen (2H/1H) isotopic compositions of organic acids, using our new MS technique, may provide a necessary constraint on the microbial ecology of marine sediments.
MARUM 2070 and via Zoom