Microbes and minerals: imaging soil C stabilization

This is a collaborative project among Drs. Markus Kleber, David Myrold, Jennifer Pett-Ridge (Lawrence Berkeley National Laboratory), and Peter Nico (Lawrence Berkeley National Laboratory) and is supported by The DOE LDRD Exploratory Research program.

This project marries two cutting-edge technologies:  high-resolution imaging spectroscopy (STXM/NEXAFS) and high-resolution imaging mass spectrometry (NanoSIMS). This unique combination will allow us for the first time to map organic C distribution, image associations of organics with specific mineral types, and trace organic matter of differing origins into the soil matrix. Our technological goal is to develop novel preparation techniques for complex organic-mineral samples and new ways to navigate and re-locate analysis sites using these two complementary instruments. Our scientific goal is to provide data to improve modeling and management of soil resources. We will develop mechanistic explanations for the carbon saturation behavior of soil fractions crucial to the long-term protection of soil carbon. Our OSU – LLNL – LBNL team proposes to tie molecular-level imaging and spectroscopy procedures to assays of microbial functionality in order to determine the role of mineral surfaces as controls on microbial processing of soil organic matter. Although this project has been completed, I continue to collaborate with Drs. Kleber and Pett-Ridge on other research efforts.

The project has produced the following publications:

Keiluweit, M., J.J. Bougoure, L.H. Zeglin, D.D. Myrold, P.K. Weber, M. Kleber, J. Pett-Ridge, and P.S. Nico. 2012. Nano-scale investigation of the association of microbial nitrogen residues with iron (hydr)oxides in a forest soil O-horizon. Geochim. Cosmochim. Acta 95:213-226.