USC Dana and David Dornsife College of Letters, Arts and Sciences

Summary Statement of Research Interests

• I am a molecular biogeochemist and my research emphasizes the interaction of the active microbial community with the geochemical environment. Specifically, I am interested in the sulfur and iron biogeochemical cycling and sediment diagenesis. It is estimated that a majority of the Earth's biomass is located within the ocean sediments and thereby cycling carbon and nutrients important for life.

  Through the use of geochemical techniques such as mass spectrometry, high pressure liquid chromatography, spectrophotometry, and solid-phase reactive/unreactive iron extraction, I have been able to characterize the porewater and solid sediment biogeochemistry. Additionally, I use molecular techniques such as RNA/DNA extraction, reverse transcription, PCR amplification, mRNA transcript quantification, and next generation sequencing to characterize the active microbial community. It is through these methods that I am trying to understand important questions for life in the subsurface:

  -How active is the microbial community within the sediment?
  -How genetically connected are microbes between global locations?
  -What geochemical variations lead to the geographic isolation of microbial communities?

  I am using sediments from the Integrated Ocean Discovery Program (IODP) Expeditions 325 (Great Barrier Reef), 329 (South Pacific Gyre), and 336 (North Pond) to explore these and many more questions. My past research has focused on both the inorganic sulfur and iron cycle as well as volatile organic sulfur compounds (VOSCs). I am interested in fluxes at the sediment-water interface and processes of the inorganic sulfur cycle as well as air-water exchange of VOSCs.