Isolation of a Microbially-Derived Fulvic Acid from a Hypereutrophic Coastal Pond in Antarctica

摘要

The study of reactivity and biogeochemistry of dissolved organic matter (DOM) has been greatly advanced by the availability of a reference material from a terrestrial source, i.e., the 1HSS Suwannee River fulvic acid, but has been limited by the lack of availability of a reference from a purely microbially based aquatic ecosystem. We have been studying the chemistry of fulvic acids from Pony Lake, a hypereutrophic coastal pond in the McMurdo Sound region of Antarctica, from 1992 through 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 extent of ice cover and timing of surface melt. The simplicity and stability of the Pony Lake ecosystem makes the lake an ideal site for collection of another reference DOM material. 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.