James Holden

Research Interests

My laboratory conducts laboratory and field research to model microbial activity in hot environments. We study the physiology of (hyper)thermophiles and employ modern biological tools to link genotypes, phenotypes, and functional responses to integrate cellular behavior within and among organisms. We employ experimental and mathematical methods to investigate the underlying principles of metabolic pathways that then lead to emerging behaviors. Ultimately, we study how individual species and microbial communities respond and adapt to environmental shifts to predict biological diversity and ecosystem dynamics.

Rates and constraints:
We model how nutrients and energy sources define the limits of growth for various thermophiles and the impact of subseafloor life on marine biogeochemistry.

Interspecies interactions:
We model how interspecies cooperation and competition affects cell growth down to the gene expression level.

Microbe-mineral interactions:
We examine microbial respiration of iron oxides and use spectroscopic techniques to identify biosignatures in nature and correlate those with host rock and fluid chemistry compositions.

Waste-to-hydrogen conversion:
We are exploring the feasibility of using hyperthermophilic heterotrophs to treat agricultural waste and produce hydrogen as a bioenergy product.