The Earth's lithosphere, hydrosphere, and atmosphere are profoundly influenced by the activities of microorganisms. Geobiological processes that underpin modern biogeochemical cycles also shaped ancient environments, from the formation of authigenic mineral deposits, to the oxygenation of Earth's early atmosphere. My primary scientific interest is to better understand interactions between the biosphere and geosphere in both modern and ancient settings. 

In order to accomplish these goals, our lab takes the following approaches:

• We study microbes and their metabolisms with the goals of better understanding their biology, evolution and biogeochemical significance. In some cases, we work with organisms that we have isolated. In other cases, we employ culture-independent approaches such as metagenomics, metatranscriptomics, and itag/amplicon-enabled community characterization.  
• We study sulfide-oxidizing lithotrophs, especially the world's largest bacteria - Thiomargarita spp.
• We study polyphosphate metabolism and its role in diverse environments, from ocean sediments to dental plaque
• We actively seek to establish new methods, such as immunodetection, for detecting and studying modern and ancient microbial activity.

Active Research and Interests

• Investigating the ecophysiology and genomics of sulfide-oxidizing bacteria such as Thiomargarita
• Exploring the role of sulfur-oxidizing bacteria in the precipitation and dissolution of authigenic minerals
• Understanding the role of polyphosphate metabolism(s) in sediment geochemistry and human dental caries
• Exploring the metabolic and ecological diversity of chemolithoautotrophic microbes
• Developing antibodies as in-situ organic biomarker detection tools

Geobiology Lab