Microorganisms collectively shape the chemistry of our planet, and have for billions of years. Understanding the activity and metabolic capabilities of microbes in the modern environment is therefore critical to understanding the history of the Earth, as well as the future of our climate.

The Dekas Lab focuses on understanding the microbiology and biogeochemistry of the deep sea: the largest and least explored habitat on the surface of our planet. We investigate the diversity, distribution and activity of marine bacteria and archaea driving carbon, nitrogen, and sulfur cycling, with a focus on processes directly and indirectly involved in the production and consumption of greenhouse gases (e.g. CH₄, CO₂ and N₂O). Using techniques from both molecular biology and isotope geochemistry, we answer questions such as: (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?

The Dekas Lab specializes in measuring the activity of bacteria and archaea on the single-cell level using nanoscale secondary ion mass spectrometry (NanoSIMS). This powerful technique measures elemental and isotopic composition at 50 nm resolution, allowing the anabolic activity of individual cells to be quantified even when closely associated with other microbial cells, particles, or host tissue. In addition to using the NanoSIMS to characterize microbial activity in our own marine samples, we collaborate with researchers interested in single-cell activity in diverse habitats, from terrestrial hot springs to pine forests. We are eager to continue expanding the breadth of microbial interactions characterized at this scale, and to link these observations with ecosystem functioning at the local and global scales.