Cawley, Kaelin听1听;听McKnight, Diane听2听;听Fimmen, Ryan听3听;听Cory, Rose听4听;听Miller, Penney听5听;听Chin, Yu-Ping听6听;听Foreman, Christine听7
1听University of Colorado at Boulder
2听University of Colorado at Boulder
3听The Ohio State University
4听University of Colorado at Boulder
5听Rose Hulman Institute of Technology
6听The Ohio State University
7听Montana State University
We have been studying the chemistry of fulvic acids from Pony Lake, a hypereutrophic coastal pond in the McMurdo Sound region of Antarctica, beginning in 1992 and continuing until 2006. The chemical characteristics of the fulvic acid fractions isolated over this time period as well as the microbial community show remarkable consistency despite dramatic changes in physical conditions such as ice cover and timing of surface melt. We characterized the fulvic acid isolates based on elemental content, 1H/13C-NMR, UV-visible absorbance, and fluorescence spectra, carbon/nitrogen isotopic composition and GC-MS analysis of hydrolysis products. NMR and GC-MS techniques provide insights into the chemical structure of the fulvic acid showing that it contains functional groups derived from cellular structures as opposed to plant-derived structures like lignin. Absorbance and fluorescence spectra elucidate the dominant chemical and biological processes governing autochthonous fulvic acid production. During the summer of 2005-2006, a reference sample of Pony Lake was collected and will be made available to serve as a microbial end-member for distribution through the International Humic Substances Society.