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Understanding Microbial Catabolism of Arctic Soil Organic Matter and Its Degradation Pathways: Identifying Precursors to Small Organic Acids


EMSL Project ID
48386

Abstract

This user proposal aims to identify the specific components of Arctic soil organic matter (SOM) that are consumed during warming experiments in the laboratory and during the thaw season at the Barrow Environmental Observatory (Barrow, AK). Microbial degradation of SOM is a preliminary step in the transformation of terrestrial carbon to small organic metabolites and ultimately greenhouse gases (GHG), carbon dioxide and methane. SOM is a complex mixture of different compounds that degrade at different rates as a result of their unique chemical properties and bioavailability to microorganisms. We plan to utilize the state-of-the-art Fourier transform ion cyclotron resonance mass spectrometers at EMSL to perform high throughput characterization of thousands of individual SOM compounds in soil extracts. Pairing SOM measurements with simultaneous analyses of small organic metabolites such as organic acids, carbon dioxide and methane, we will attempt to resolve a significant knowledge gap regarding what specific components or pools of SOM are degraded in processes that generate GHG, which will help to better predict the role of Arctic soil carbon in a warmer climate.

Project Details

Project type
Large-Scale EMSL Research
Start Date
2014-10-01
End Date
2015-09-30
Status
Closed

Team

Principal Investigator

Baohua Gu
Institution
Oak Ridge National Laboratory

Team Members

Hongmei Chen
Institution
Oak Ridge National Laboratory

Benjamin Mann
Institution
Oak Ridge National Laboratory

Related Publications

Mann BF, HM Chen, EM Herndon, RK Chu, N Tolic, EF Portier, TR Chowdhury, EW Robinson, SJ Callister, SD Wullschleger, DE Graham, LY Liang, and BH Gu. 2015. "Indexing Permafrost Soil Organic Matter Degradation Using High-Resolution Mass Spectrometry." PLoS One 10:16. doi:10.1371/journal.pone.0130557