The Abundance of Ammonium-Oxidizing Bacteria in Lake Bonney, Antarctica Determined by Immunofluorescence, Pcr and In Situ Hybridization
- John C. Priscu
Published Online: 16 MAR 2013
Copyright 1998 by the American Geophysical Union.
Ecosystem Dynamics in a Polar Desert: the Mcmurdo Dry Valleys, Antarctica
How to Cite
Voytek, M. A., Ward, B. B. and Priscu, J. C. (1998) The Abundance of Ammonium-Oxidizing Bacteria in Lake Bonney, Antarctica Determined by Immunofluorescence, Pcr and In Situ Hybridization, in Ecosystem Dynamics in a Polar Desert: the Mcmurdo Dry Valleys, Antarctica (ed J. C. Priscu), American Geophysical Union, Washington, D. C.. doi: 10.1029/AR072p0217
- Published Online: 16 MAR 2013
- Published Print: 28 JAN 1998
Print ISBN: 9780875908991
Online ISBN: 9781118668313
- Desert ecology—Antarctica—McMurdo Dry Valleys
Previous studies of biogeochemical cycling in Lake Bonney, Antarctica, suggest that nitrification plays a central role in controlling the depth distributions of oxidized and reduced inorganic nitrogen in both east and west lobes. For example, there is a mid-depth N2O-N maximum of 41.6 μg at 1−1 (>500,000% saturation) in the east lobe, the highest level reported for a natural system. The source of this N2O peak is thought to be nitrification under conditions of low oxygen tension. Although nitrifying bacteria have been detected, attempts to isolate and culture them have been unsuccessful. This study examines three techniques for the determination of abundance of nitrifying bacteria in this lake. Applying a polymerase chain reaction (PCR) assay developed for the detection of ammonium-oxidizing bacteria belonging to the beta and gamma subclasses of the Proteobacteria, immunofluorescent antibody assay (IFA) and fluorescent probe in situ hybridization (FISH) techniques, the distribution and relative abundance of ammonium-oxidizers was examined. In general, nitriflers were detected at depths above the pycnocline and usually associated with decreasing concentrations of NH4+ and increasing concentrations of NO3− or NO2−. These data are consistent with the chemical distributions and the role of nitrifying bacteria in determining the distribution of nitrogen compounds in this lake.