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Effects of estuarine sediment hypoxia on nitrogen fluxes and ammonia oxidizer gene transcription


Abell, GCJ and Banks, J and Ross, DJ and Keane, JP and Robert, SS and Revill, AT and Volkman, JK, Effects of estuarine sediment hypoxia on nitrogen fluxes and ammonia oxidizer gene transcription, FEMS Microbiology Ecology, 75, (1) pp. 111-122. ISSN 1574-6941 (2011) [Refereed Article]

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DOI: doi:10.1111/j.1574-6941.2010.00988.x


The effects of sediment hypoxia, resulting from increased carbon loads or decreased dissolved oxygen (DO), on nitrogen cycling in estuarine environments is poorly understood. The important role played by bacterial and archaeal ammonia oxidizers in the eventual removal of nitrogen from estuarine environments is likely to be strongly affected by hypoxic events. In this study, an analysis of the effects of different levels of sediment hypoxia (5%, 20% and 75% DO) was performed in a microcosm experiment. Changes in the nutrient fluxes related to nitrification at 5% DO were observed after 4 h. Quantification of the key nitrification gene ammonium monooxygenase (amoA) in both DNA and RNA extracts suggests that bacterial amoA transcription was reduced at both of the lower DO concentrations, while changes in DO had no significant effect on archaeal amoA transcription. There was no change in the diversity of expressed archaeal amoA, but significant change in bacterial amoA transcriptional diversity, indicative of low- and high-DO phylotypes. This study suggests that groups of ammonia oxidizers demonstrate differential responses to changes in sediment DO, which may be a significant factor in niche partitioning of different ammonia oxidizer groups.

Item Details

Item Type:Refereed Article
Keywords:nitrification; hypoxia; estuary; amoA
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Fisheries sciences
Research Field:Aquaculture and fisheries stock assessment
Objective Division:Environmental Management
Objective Group:Terrestrial systems and management
Objective Field:Assessment and management of terrestrial ecosystems
UTAS Author:Ross, DJ (Associate Professor Jeff Ross)
UTAS Author:Keane, JP (Dr John Keane)
ID Code:75056
Year Published:2011
Web of Science® Times Cited:38
Deposited By:Sustainable Marine Research Collaboration
Deposited On:2012-01-05
Last Modified:2017-11-03
Downloads:1 View Download Statistics

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