Current Research

Limits and Detectability of Life

We study how microbial life persists, adapts, and remains detectable in environments with limited energy, water, nutrients, or biomass. Our work explores how environmental stress shapes microbial activity across systems including the deep subsurface, dry permafrost, hydrothermal environments, and Earth’s atmosphere. By combining field sampling, geochemistry, and single-cell activity measurements, we investigate the boundary conditions of life and their implications for planetary habitability and biosignature detection.

This research spans environments ranging from oceanic crust and hydrothermal systems to Antarctic permafrost, dryland soils, and Earth’s atmosphere. We combine field exploration, microbial cultivation, geochemistry, environmental sequencing, and single-cell imaging approaches to investigate microbial activity across diverse environmental gradients and scales.

Core Questions

• What limits microbial activity in low-energy and low-biomass systems?

• How can active life be detected near environmental boundaries?

• How do persistence and activity become decoupled?

Example Systems

• deep subsurface

• atmosphere

• dry permafrost

• hydrothermal systems

Example Approaches

• SIP–NanoSIMS (see image)

• isotope probing

• environmental sequencing

• geochemistry