Hansel Lab in

Microbial Geochemistry


Research in the Hansel lab sits at the intersection of mineralogy, geochemistry, and microbiology with the goal of disentangling the reaction networks that mediate metal and mineral dynamics in natural systems. We are broadly interested in how Earth’s changing climate impacts key mineralization reactions essential for organismal health and functioning, including coral calcification, diatom silicification, and mineral-based metabolisms (e.g., iron-reducing microbes). Over the past decade, our research has converged upon a central and unifying concept – that metal and mineral cycling are oftentimes mediated by short-lived reactive inorganic metabolites. These include both aqueous and solid-phase intermediates, such as reactive oxygen species (ROS), intermediate manganese species (Mn3+), and highly reactive colloidal elemental sulfur (S0) and oxide phases. While these reactive intermediates are present in low concentrations within natural systems, they have a disproportionately large influence on mineral and biogeochemical cycles, involving elements ranging from carbon to uranium. Rapid production and consumption of these reactive intermediates leads to a hidden rapidly spinning ‘cryptic’ wheel that underpins a myriad of elemental cycles in marine and terrestrial systems. These essential, cryptic cycles have become a focal point of our research and will be a central theme in the lab for the foreseeable future.

In studying these complex systems, we employ a number of sophisticated and complementary geochemical and microbiological approaches, including synchrotron-based X-ray spectroscopy and fluorescence microscopy to determine the speciation and distribution of metals and minerals, targeted and untargeted genetics and proteomics to discover genes and proteins involved in mineralization, metal redox transformations and reactive metabolite generation, and electrochemical and analytical chemistry methods for quantification of short-lived reactive intermediates.



Last updated: July 2016