Seasonal variation in denitrification and dissimilatory nitrate reduction to ammonia process rates and corresponding key functional genes along an estuarine nitrate gradient

Smith, C. J. , Dong, L. F., Wilson, J., Stott, A., Osborn, A. M. and Nedwell, D. B. (2015) Seasonal variation in denitrification and dissimilatory nitrate reduction to ammonia process rates and corresponding key functional genes along an estuarine nitrate gradient. Frontiers in Microbiology, 6, 542. (doi: 10.3389/fmicb.2015.00542) (PMID:26082763) (PMCID:PMC4451412)

Abstract

This research investigated spatial-temporal variation in benthic bacterial community structure, rates of denitrification and dissimilatory nitrate reduction to ammonium (DNRA) processes and abundances of corresponding genes and transcripts at three sites—the estuary-head, mid-estuary and the estuary mouth (EM) along the nitrate gradient of the Colne estuary over an annual cycle. Denitrification rates declined down the estuary, while DNRA rates were higher at the estuary head and middle than the EM. In four out of the six 2-monthly time-points, rates of DNRA were greater than denitrification at each site. Abundance of gene markers for nitrate-reduction (nitrate reductase narG and napA), denitrification (nitrite reductase nirS) and DNRA (DNRA nitrite reductase nrfA) declined along the estuary with significant relationships between denitrification and nirS abundance, and DNRA and nrfA abundance. Spatially, rates of denitrification, DNRA and corresponding functional gene abundances decreased along the estuary. However, temporal correlations between rate processes and functional gene and transcript abundances were not observed.

• Item Type: Articles
• Additional Information: This work was supported by the Natural Environment Research Council of the UK through research grant NER/A/S/2002/00962 awarded to DN and AO. CS is currently supported by SFI Starting Investigator-COFUND fellowship (11/SIRG/B2159).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Smith, Professor Cindy
• Authors: Smith, C. J., Dong, L. F., Wilson, J., Stott, A., Osborn, A. M., and Nedwell, D. B.
• College/School: College of Science and Engineering > School of Engineering > Infrastructure and Environment
• Journal Name: Frontiers in Microbiology
• Publisher: Frontiers Media
• ISSN: 1664-302X
• ISSN (Online): 1664-302X
• Copyright Holders: Copyright © 2015 Smith, Dong, Wilson, Stott, Osborn and Nedwell
• First Published: First published in Frontiers in Microbiology 6:542
• Publisher Policy: Reproduced under a creative commons license