School of Biological Sciences

Senior Research Officer: A new dynamic for Phosphorus in Riverbed Nitrogen Cycling - PRINCe

The post will involve working on a UK Natural Environment Research Council (NERC) funded project "A new dynamic for Phosphorus in Riverbed Nitrogen Cycling - PRINCe". This project is a collaboration between Drs Boyd McKew, Corinne Whitby and Philippe Laissue (University of Essex) and Prof M Trimmer (Queen Mary University of London). The post will be based at the University Of Essex, Colchester Campus but will involve fieldwork and periods working at Queen Mary University (in collaboration with a second post-doctoral researcher, who will be based at Queen Mary University).

This project addresses a very novel and exciting aspect of nutrient processing in river beds by investigating whether P limitation changes the way that N cycling occurs. The results from this study have the potential to change our understanding of how this process works and the environmental and biological factors that control it, and could lead to changes in the management of catchments and wastewater treatment systems. It is based on our recent ground-breaking work demonstrating the detailed N cycling pathways in river beds with different sediments and underlying geology, which also revealed that anammox is an entirely unexpected key pathway to dinitrogen in chalk streams.

The anthropogenic doubling of fixed N has come at a considerable cost to aquatic ecosystems, particularly rivers, which provide an important ecosystem service in attenuating high nitrogen loads. The coupling between nitrification and denitrification was the consensus view on how fixed N was removed in rivers, but recently, anaerobic ammonium oxidation (anammox) has been shown to be an alternative important process, whereby nitrite and ammonia are converted more simply to N2 gas. This project will aim to understand the dynamics of phosphorous regulation of N cycling from a molecular and biogeochemical perspective in rivers along a natural gradient in P. We will test our overarching hypothesis that P limitation of nitrite oxidation creates a "nitrite-niche" that is particularly favourable for anammox which, in turn, maximises the conversion of ammonium to N2 gas.

The project uses field measurements across a wide range of sites in an established and well characterised network of rivers, combined with lab-based flow through experiments and cutting-edge microscopy.

The duties of this role will involve:

  • To conduct research to meet the objectives of NERC grant NE/ P011624/1 on " A new dynamic for Phosphorus in Riverbed Nitrogen Cycling - PRINCe"
  • Quantifying the structure of N-cycling communities, the absolute abundance of N-cycle functional genes and their activity via transcript expression of amoA (ammonia oxidising Archaea (AOA) and bacteria (AOB)), nxr (NOB), hzo, hzs (anammox bacteria) , nirK and nirS (denitrifiers) in relation to P availability in both rivers and experimental flow-through reactors (using q-PCR, qRT-PCR and NGS amplicon sequencing).
  • To disseminate the results of this research in peer-reviewed scientific papers and presentations at national and international conferences.
  • Identifying the spatial distribution and potential coupling of active anammox/nitrifier/denitrifier microbes in relation to P availability (using CARD-FISH/Gene-FISH and three-dimensional, multispectral microscopy).
  • To participate in public understanding of science and research dissemination activities related to this project.

It is essential that the successful candidate has a PhD in an appropriate discipline and an Undergraduate BSc degree (1st or 2:1 class). You will have knowledge in Environmental Microbiology and experience with DNA/RNA extraction, PCR, qPCR and RT-qPCR.

At the University of Essex internationalism is central to who we are and what we do. We are committed to being a cosmopolitan, internationally-oriented university that is welcoming to staff and students from all countries and a university where you can find the world in one place.

Please visit our website ( for a full job description, person specification and more information relating to this post (Ref: REQ00538). We recommend you read this information carefully before making an application. Applications should be made on-line, but if you would like advice or help in making an application, or need information in a different format, please telephone the Resourcing Team (01206 874693/873521).

Salary: 32,004 - 38,183 per annum
Closing date: 23 April 2017
Interviews are planned for: To be confirmed

posted: 30 March 2017 Please mention EARTHWORKS when responding to this advertisement.