Nitrate uptake by heterotrophic bacteria and the diversity of bacterial nitrate assimilation genes in marine systems
This study focused on the development of molecular methods to assay the diversity and abundance of groups of heterotrophic bacteria that are capable of aerobic NO3 - assimilation. The variability of the abundance and diversity of populations of heterotrophic bacteria capable of NO3 - utilization was...
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ftunivgeorgia:oai:athenaeum.libs.uga.edu:10724/20492 2023-05-15T15:38:44+02:00 Nitrate uptake by heterotrophic bacteria and the diversity of bacterial nitrate assimilation genes in marine systems Allen, Andrew Ellis 2002-05 http://hdl.handle.net/10724/20492 http://purl.galileo.usg.edu/uga_etd/allen_andrew_e_200205_phd unknown uga allen_andrew_e_200205_phd http://purl.galileo.usg.edu/uga_etd/allen_andrew_e_200205_phd http://hdl.handle.net/10724/20492 public Nitrate uptake 15N PCR Q-PCR T-RFLP nasA Heterotrophic bacteria Marine bacteria Nitrogen cycle estuary Dissertation 2002 ftunivgeorgia 2020-09-23T12:11:32Z This study focused on the development of molecular methods to assay the diversity and abundance of groups of heterotrophic bacteria that are capable of aerobic NO3 - assimilation. The variability of the abundance and diversity of populations of heterotrophic bacteria capable of NO3 - utilization was studied in relation to patterns of bacterial NO3 - uptake as indicated by 15 N uptake experiments. A PCR primer set that could be used to selectively amplify a fragment of the nasA gene (assimilatory nitrate reductase) from heterotrophic bacteria was designed. Results suggest that nine groups of heterotrophic bacterial nasA genes are common and widely distributed in oceanic environments. 15 N tracer experiments conducted in the Barents Sea and in the South Atlantic Bight indicate that bacteria assimilate, on average, between 15 and 40 % of the available NO3 - . These results suggest that bacteria play a larger role in NO3 - utilization than previously hypothesized and that bacterial uptake of NO3 - should not be ignored in estimates of new production. In the Barents Sea Marinobacter sp. nasA gene abundance, measured via a SYBR Green real-time PCR assay, was positively correlated with NO3 - , showing a two-fold increase in concentration relative to total bacteria at 80 m compared to 5 m. Compared to other variables tested, NO3 - is the best predictor, by a factor of 10, of the variability associated with nasA community structure (assayed via T-RFLP) across the different water masses sampled in the Barents Sea. Studies conducted in the Skidaway River estuary in the South Atlantic Bight indicated a strong correlation, across seasons, between Marinobacter sp. nasA gene abundance and the magnitude of bacterial NO3 - uptake. Of the different variables assayed, NO3 - uptake rate was the best predictor, by a factor of 15, of the variability associated with nasA community structure. The finding that NO3 - availability and patterns of NO3 - utilization are positively correlated with nasA community structure variability and the abundance of particular groups of nasA genes, indicates that patterns of NO3 - supply, in the marine environment, are sufficiently important to be a factor in regulating bacterial communities. PhD Ecology Ecology Peter Verity Peter Verity Marc Frischer Tim Hollibaugh Mary Ann Moran Samantha Joye Doctoral or Postdoctoral Thesis Barents Sea University of Georgia: Athenaeum@UGA Barents Sea |
institution |
Open Polar |
collection |
University of Georgia: Athenaeum@UGA |
op_collection_id |
ftunivgeorgia |
language |
unknown |
topic |
Nitrate uptake 15N PCR Q-PCR T-RFLP nasA Heterotrophic bacteria Marine bacteria Nitrogen cycle estuary |
spellingShingle |
Nitrate uptake 15N PCR Q-PCR T-RFLP nasA Heterotrophic bacteria Marine bacteria Nitrogen cycle estuary Allen, Andrew Ellis Nitrate uptake by heterotrophic bacteria and the diversity of bacterial nitrate assimilation genes in marine systems |
topic_facet |
Nitrate uptake 15N PCR Q-PCR T-RFLP nasA Heterotrophic bacteria Marine bacteria Nitrogen cycle estuary |
description |
This study focused on the development of molecular methods to assay the diversity and abundance of groups of heterotrophic bacteria that are capable of aerobic NO3 - assimilation. The variability of the abundance and diversity of populations of heterotrophic bacteria capable of NO3 - utilization was studied in relation to patterns of bacterial NO3 - uptake as indicated by 15 N uptake experiments. A PCR primer set that could be used to selectively amplify a fragment of the nasA gene (assimilatory nitrate reductase) from heterotrophic bacteria was designed. Results suggest that nine groups of heterotrophic bacterial nasA genes are common and widely distributed in oceanic environments. 15 N tracer experiments conducted in the Barents Sea and in the South Atlantic Bight indicate that bacteria assimilate, on average, between 15 and 40 % of the available NO3 - . These results suggest that bacteria play a larger role in NO3 - utilization than previously hypothesized and that bacterial uptake of NO3 - should not be ignored in estimates of new production. In the Barents Sea Marinobacter sp. nasA gene abundance, measured via a SYBR Green real-time PCR assay, was positively correlated with NO3 - , showing a two-fold increase in concentration relative to total bacteria at 80 m compared to 5 m. Compared to other variables tested, NO3 - is the best predictor, by a factor of 10, of the variability associated with nasA community structure (assayed via T-RFLP) across the different water masses sampled in the Barents Sea. Studies conducted in the Skidaway River estuary in the South Atlantic Bight indicated a strong correlation, across seasons, between Marinobacter sp. nasA gene abundance and the magnitude of bacterial NO3 - uptake. Of the different variables assayed, NO3 - uptake rate was the best predictor, by a factor of 15, of the variability associated with nasA community structure. The finding that NO3 - availability and patterns of NO3 - utilization are positively correlated with nasA community structure variability and the abundance of particular groups of nasA genes, indicates that patterns of NO3 - supply, in the marine environment, are sufficiently important to be a factor in regulating bacterial communities. PhD Ecology Ecology Peter Verity Peter Verity Marc Frischer Tim Hollibaugh Mary Ann Moran Samantha Joye |
format |
Doctoral or Postdoctoral Thesis |
author |
Allen, Andrew Ellis |
author_facet |
Allen, Andrew Ellis |
author_sort |
Allen, Andrew Ellis |
title |
Nitrate uptake by heterotrophic bacteria and the diversity of bacterial nitrate assimilation genes in marine systems |
title_short |
Nitrate uptake by heterotrophic bacteria and the diversity of bacterial nitrate assimilation genes in marine systems |
title_full |
Nitrate uptake by heterotrophic bacteria and the diversity of bacterial nitrate assimilation genes in marine systems |
title_fullStr |
Nitrate uptake by heterotrophic bacteria and the diversity of bacterial nitrate assimilation genes in marine systems |
title_full_unstemmed |
Nitrate uptake by heterotrophic bacteria and the diversity of bacterial nitrate assimilation genes in marine systems |
title_sort |
nitrate uptake by heterotrophic bacteria and the diversity of bacterial nitrate assimilation genes in marine systems |
publisher |
uga |
publishDate |
2002 |
url |
http://hdl.handle.net/10724/20492 http://purl.galileo.usg.edu/uga_etd/allen_andrew_e_200205_phd |
geographic |
Barents Sea |
geographic_facet |
Barents Sea |
genre |
Barents Sea |
genre_facet |
Barents Sea |
op_relation |
allen_andrew_e_200205_phd http://purl.galileo.usg.edu/uga_etd/allen_andrew_e_200205_phd http://hdl.handle.net/10724/20492 |
op_rights |
public |
_version_ |
1766370024204795904 |