Claire Brown

Influence of microbial community on nitrogen use efficiency in agriculture (NPIF)

About me

I completed my integrated masters in microbiology and biotechnology at the University of York. For my third-year project with Dr James Chong, I used isolation chips to isolate novel antimicrobial producing microbes from soil. This gave me a great introduction to molecular ecology and sequencing techniques including Illumina MiSeq and Nanopore sequencing. This project led to my interest in microbial ecology. During my masters project with Dr Ville Friman, I investigated the effects of combined phage and antibiotic therapies on biofilm-forming bacteria. This led to my first first-author publication “Rapid evolution of generalised resistance mechanisms can constrain the efficacy of phage-antibiotic treatments”.

Following my masters, I was offered an NPIF PhD project on the influence of microbial community on nitrogen use efficiency in agriculture, in collaboration with Precision Decisions Ltd, at the University of York. I’m now in my third year [from Oct 2019] and about to start a three-month placement with the company to investigate whether my findings apply in different environmental settings.

My project

Denitrification, the step-wise reduction of nitrate to gases including nitrous oxide and dinitrogen, is an important process in nitrogen cycling. One of the gases involved in denitrification is nitrous oxide, an ozone-depleting greenhouse gas which is 296 times more potent than carbon dioxide (IPCC, 2007). Denitrification is thought to account for 60% of global nitrous oxide emissions (Kroeze, Mosier, and Bouwman 1999), but also acts as the only biological sink for nitrous oxide (Seitzinger et al. 2006). Therefore, the study of microbes in relation to denitrification rate is an important step for the reduction of nitrous oxide emissions.

As well as studying denitrification from an environmental perspective, my project focusses on agricultural productivity losses caused by denitrification. Since nitrogen deficiency is the major limiting nutrient for agricultural productivity (Good & Beatty, 2011), and denitrification leads to loss of nitrate and a net loss of nitrogen from the terrestrial ecosystem, it is imperative that this process is better understood in order to feed the growing global population.

My project looks at how a number of factors including land management, environmental conditions and ecological phenomena affect the distribution of denitrifying microbes in arable soils and whether any predictive tests for denitrification rate can be developed for use in the farming industry to better decide whether to fertilize a given area.


Twitter: @Claire_Brown_21