HR: 0800h
AN: H21A-0996    [Abstracts]
TI: Using {\it nirS} gene expression as a proxy for denitrification rate
AU: * Bachmann, M
EM: mbachmann@geosc.psu.edu
AF: Department of Geosciences, The Pennsylvania State University, University Park, Pa 16802 United States
AU: Kump, L
EM: kump@geosc.psu.edu
AF: Department of Geosciences, The Pennsylvania State University, University Park, Pa 16802 United States
AU: Regan, J
EM: JRegan@engr.psu.edu
AF: Department of Geosciences, The Pennsylvania State University, University Park, PA 16802 United States
AB: Quantification of microbial respiration rates in subsurface environments is complicated by difficult access to samples, impervious aquifer materials, and a lack of information about groundwater transport processes. Here, Quantitative Reverse Transcriptase Polymerase Chain Reaction (Q-RT-PCR) is investigated as a novel method of directly quantifying biological denitrification rates on a single sample using a single measurement. Benchtop batch reactors innoculated with the model organism {\it Paracoccus denitrificans} are sampled for denitrification rate as measured by mass balance, and these rates are then correlated with the abundance of expressed copies of the nitrite reductase gene {\it nirS}. Future work will examine the applicability of this technique to mixed cultures and environmental samples.
DE: 4805 Biogeochemical cycles (1615)
DE: 4845 Nutrients and nutrient cycling
DE: 4802 Anoxic environments
DE: 1803 Anthropogenic effects
DE: 1829 Groundwater hydrology
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting