Molecular microbial ecology of ammonia oxidation in coastal sediments
|dc.description.abstract||This thesis focuses on the processes of nitrification in three coastal bays, specifically, aerobic ammonia oxidation which is the rate limiting step of nitrification and is mediated by ammonia oxidising bacteria and/or archaea (AOB/AOA). Rusheen, Clew and Kinvarra bay are located on the Atlantic coast of Ireland. The aim of this project is to combine in situ field data with experimental approaches, addressing temporal and spatial changes in ammonia oxidiser (AO) activity, abundance and diversity across environmental gradients in coastal bay ecosystems, in order to elucidate the key AO and environmental drivers within dynamic intertidal sediment ecosystems. Using this approach we report for the first time transcriptionally active AOB and AOA were present within Rusheen bay intertidal sediments, bringing us a step closer to confirming actively nitrifying co-occurring AOB and AOA in intertidal sediments. In chapter three we observe the huge diversity that can be found in coastal sediments. We show that using 16S rRNA transcripts enables us to identify low abundant or rare OTUs that were not picked up by sequencing DNA alone. Finally in chapter four through the use of experimental sediment microcosm incubations combined with SIP, we were able to demonstrate the growth and activity of Nitrosoarchaeum like AOAs in a low salinity habitat originating from intertidal coastal sediment. In addition throughout all three chapters we saw the impact environmental conditions such as nutrient concentrations, salinity, pH and temperature have on driving the distribution of communities within intertidal sediments.||en_IE|
|dc.title||Molecular microbial ecology of ammonia oxidation in coastal sediments||en_IE|
|dc.contributor.funder||Science Foundation Ireland||en_IE|
|dc.local.note||The nitrogen cycle is of critical importance to all life on earth. This thesis focuses on understanding one step in the nitrogen cycle called nitrification. Microorganisms such as bacteria and Archaea are involved in facilitating steps in the nitrogen cycle. This study investigates the effects of different parameters such as salinity on the microorganisms that mediate the nitrification step.||en_IE|
Files in this item
This item is available under the Attribution-NonCommercial-NoDerivs 3.0 Ireland. No item may be reproduced for commercial purposes. Please refer to the publisher's URL where this is made available, or to notes contained in the item itself. Other terms may apply.
The following license files are associated with this item: