Sources of organic electron donors for microbial iron reduction in the subsurface of Earth and Mars
- Event time: 1:00pm
- Event date: 18th November 2013
- Speaker: Sophie Nixon (Formerly School of Physics & Astronomy, University of Edinburgh)
- Location: Room 2511, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB
The microbial mediation of iron reduction reactions in the subsurface is a significant contributor to the global cycling of Carbon and Iron on Earth. It also represents a compelling candidate metabolism operating in the subsurface of Mars. However, our knowledge of the limits and metabolic capabilities of microbial iron reduction is confined, largely caused by research bias towards practical applications, such as bioremediation and microbial fuel cells. Iron reducing bacteria (IRB) typically utilise organic compounds as electron donors for the reduction of ferric iron. In order to constrain the habitability of Mars for such life, it is critical to better understand the ability of iron reducing microorganisms to utilize complex ancient sources of organic compounds, such as shales, kerogens and carbonaceous meteorites. In this talk I will present initial results from a series of growth experiments in which the ability of IRB to reduce iron with the concurrent oxidation of organic compounds in shales and kerogens is assessed. Results indicating that non-proteinogenic D-amino acids common to carbonaceous meteorites may inhibit microbial iron reduction will also be presented, and the implications for the search for iron-reducing microorganisms on Mars discussed.
This is a weekly series of informal talks given primarily by members of the soft condensed matter and statistical mechanics groups, but is also open to members of other groups and external visitors. The aim of the series is to promote discussion and learning of various topics at a level suitable to the broad background of the group. Everyone is welcome to attend..