The role of bacteria in recycling dissolved organic matter in freshwater and marine environments is, at present, pooly known. Yet because dissolved organic matter is one of the largest pools of biospheric carbon, knowledge of the processes involved in its formation and biological utilization is essential for a full understanding of global carbon cycling. One particular class of dissolved organic matter, the humic substances, is of particular interest because it makes up a very large fraction of the total dissolved substances (up to 80% in some natural environments) but has been very poorly studied in the past. We propose to examine the bacterial processes involved in recycling (formation and utilization ) of dissolved humic substances in a freshwater wetland in the southeastern United States (the Okefenokee Swamp Ecosystem).
