EESS Winter Seminar Series, Anne Dekas, Lawrence Livermore National Laboratory
EESS Winter Seminar Series, Anne Dekas, Lawrence Livermore National Laboratory, "Microbial activity and metabolic flexibility: Implications for global C and N cycling", Abstract: Microbial metabolisms collectively shape the chemistry of our planet, making understanding microbial activity a key to understanding and anticipating trends in climate. Recent molecular research has revolutionized our understanding of the vast diversity and distribution of microbes, but less is known about microbial activity, particularly on the single-cell level. In my future work, I plan to investigate the metabolic activity and flexibility of uncultured microbes in complex natural communities to address questions including: (1) “who” is doing “what” (linking phylogenetic identity to physiological function), (2) what are the biogeochemical controls on metabolic rates, (3) how do specific metabolisms affect global scale biogeochemical cycles and climate, and (4) will these metabolisms act as a positive or negative feedback to climate change? I’ll begin this talk with a brief description of the evolution of my interests, from astronomy to astrobiology to geobiology. Then I’ll describe my current work at Lawrence Livermore National Laboratory (LLNL), where I am investigating the carbon metabolic flexibility of marine and terrestrial Thaumarchaea. In particular, I will discuss how nanoscale secondary ion mass spectrometry (NanoSIMS) provides unique insight into microbial activity, and describe a new NanoSIMS-based technique developed at LLNL, Chip-SIP, which facilitates high-throughput stable isotope probing. Then, I will discuss specific examples of research questions I would like to pursue in my future work, each relating to the metabolic diversity and flexibility of marine microorganisms, with a focus on archaea, and how they impact global C and N cycling.