Detection, diversity, and activity on anaerobic ammonium oxidizing bacteria (Anammox) in the Cape Fear River Estuary

• Main Authors: Dale, Olivia R., NC DOCKS at The University of North Carolina Wilmington
• Language: English
• Published: 2009
• Subjects: Pollutants > North Carolina > Cape Fear River Estuary; Nitrogen cycle > North Carolina > Cape Fear River Estuary; Bacteria > Ecology; Bacteria; Denitrifying > Ecology > North Carolina > Cape fear Estuary; Nitrogen-fixing microorganisms > North Carolina > Cape fear Estuary; Arctic; Sea ice
• Online Access: http://libres.uncg.edu/ir/uncw/f/daleo2007-1.pdf

Anammox is a new pathway in the nitrogen cycle, in which NH4+ oxidiation is coupled to NO2- reduction to produce N2. Anammox was first discovered in a wastewater treatment plant in 1995, and the process was attributed to bacteria that branch deeply in the bacterial genus Planctomycetes. Since this initial finding, anammox bacteria have been detected in anoxic marine sediments, oxygen minimum zones of the oceanic water column, estuaries, arctic sea ice, and even a freshwater lake. Activity measurements have further revealed that these bacteria can contribute significantly to the nitrogen removal process. This chemolithotrophic process is a new loop in the biogeochemical nitrogen cycle that was previously unknown. Prior to the discovery of anammox, denitrification was considered to be the only process responsible for nitrogen removal via N2 gas production. Little is known about the genetics, ecology, and physiology of this organism. Therefore, this study was an attempt to gain better understanding in the community structure of anammox bacteria and their activity related to environmental parameters such as, ammonium, nitrate, and salinity levels. The Cape Fear River Estuary was chosen as the study site. A combination of molecular tools and stable isotope probing technique was employed to study anammox bacteria in the Cape Fear River Estuary. Anammox bacteria were identified at all three sampling sites, and each site had distinct community structure. Salinity and ammonium levels were positively correlated with diversity. Although, no correlation could be established between environmental parameters and activity levels, there did seem to be a link between community structure and activity levels.