Partners in crime: Does microbial cooperation exacerbate nitrous oxide emission from soil?
Lead Research Organisation:
University of Warwick
Abstract
Context: Human interference with the nitrogen cycle is one of the greatest threats to humanity and has profound impacts on food production, environmental change and the Earth’s climate. Nitrous oxide (N2O) is a potent greenhouse gas produced by microorganisms during nitrogen cycling, and the most important ozone-depleting substance of the 21st century. It is estimated that up to 70% of ammonia-based fertiliser is lost from agricultural fields through microbial activity, exemplifying the acute need to urgently gain a better understanding of microorganisms involved in nitrogen cycling. This project will determine how previously unsuspected microbial interactions dictate nitrogen cycling and N2O production from soil, and in doing so, has every likelihood to provide new tools for mitigating climate change.
Challenge and the knowledge gap: Little is known about how microorganisms, and in particular microbial interactions and cooperation, result in N2O emission. Production of N2O in most soil ecosystems requires multiple processes in the nitrogen cycle, and notably, there is no single microorganisms which can carry out all the parts of the nitrogen cycle. Therefore, for N2O emission to occur, it is overwhelmingly likely, but little explored, that microorganisms ‘team up’, but how such microbial interactions are orchestrated is unknown. Soil represents a black box which hides the mechanisms and microorganisms underpinning process rates and responses. This knowledge gap makes it challenging to predict and manage nitrogen flux in the soil environment. This project will reveal how soil microorganisms and their cooperation cause a previously unexplored connection between the nitrogen and carbon cycles with important implications for greenhouse gas emissions.
Hypothesis and approach: We hypothesise that ammonia oxidising archaea, which are among the most numerous living organisms on the planet, interact with denitrifying microorganisms to exacerbate N2O production from terrestrial ecosystems. This project uses an adventurous and unconventional combination of chemistry and biology approaches to determine how microbial partnerships cause N2O production from soil. We will apply NMR and LC-MS to examine the exchange of metabolites between nitrifying and denitrifying microorganisms and ascertain the impacts of these trades on microbial growth, activity, and nitrogen cycling processes. To investigate the microbial networks in situ in soil, we will deploy a novel treble stable isotope probing (SIP) approach combining DNA-SIP, RNA-SIP and NMR-SIP for heavy carbon isotope tracing. This will deliver unprecedented insights on the microbial identity, metabolic pathways, metabolite exchanges, and microbial interactions which underpin the N2O emission from soil.
Timeliness and impact: This research is pressingly timely because rainfall and flooding are increasing in frequency due to climate change, and these conditions trigger changes to nitrification and denitrification rates, and exacerbate N2O production. Moreover, anthropogenic input and dependence on reactive nitrogen is causing profound changes in the environment through leaching of nitrate, eutrophication and emission of nitrogenous climate-active gases. Disruption of links in microbial networks, and selectively inhibiting members of the microbiome may provide novel interventions for managing nitrogen budgets, help towards future-proofing against climate change and contribute towards the UK government’s net zero targets. Both nitrogen and carbon cycles are essential ecosystem services, which define the fertility and resilience of our soils and food security. This project will benefit the UK farming sector and economy, with positive impacts on the general public through potential to reduce food prices and improved access to clean environment.
Challenge and the knowledge gap: Little is known about how microorganisms, and in particular microbial interactions and cooperation, result in N2O emission. Production of N2O in most soil ecosystems requires multiple processes in the nitrogen cycle, and notably, there is no single microorganisms which can carry out all the parts of the nitrogen cycle. Therefore, for N2O emission to occur, it is overwhelmingly likely, but little explored, that microorganisms ‘team up’, but how such microbial interactions are orchestrated is unknown. Soil represents a black box which hides the mechanisms and microorganisms underpinning process rates and responses. This knowledge gap makes it challenging to predict and manage nitrogen flux in the soil environment. This project will reveal how soil microorganisms and their cooperation cause a previously unexplored connection between the nitrogen and carbon cycles with important implications for greenhouse gas emissions.
Hypothesis and approach: We hypothesise that ammonia oxidising archaea, which are among the most numerous living organisms on the planet, interact with denitrifying microorganisms to exacerbate N2O production from terrestrial ecosystems. This project uses an adventurous and unconventional combination of chemistry and biology approaches to determine how microbial partnerships cause N2O production from soil. We will apply NMR and LC-MS to examine the exchange of metabolites between nitrifying and denitrifying microorganisms and ascertain the impacts of these trades on microbial growth, activity, and nitrogen cycling processes. To investigate the microbial networks in situ in soil, we will deploy a novel treble stable isotope probing (SIP) approach combining DNA-SIP, RNA-SIP and NMR-SIP for heavy carbon isotope tracing. This will deliver unprecedented insights on the microbial identity, metabolic pathways, metabolite exchanges, and microbial interactions which underpin the N2O emission from soil.
Timeliness and impact: This research is pressingly timely because rainfall and flooding are increasing in frequency due to climate change, and these conditions trigger changes to nitrification and denitrification rates, and exacerbate N2O production. Moreover, anthropogenic input and dependence on reactive nitrogen is causing profound changes in the environment through leaching of nitrate, eutrophication and emission of nitrogenous climate-active gases. Disruption of links in microbial networks, and selectively inhibiting members of the microbiome may provide novel interventions for managing nitrogen budgets, help towards future-proofing against climate change and contribute towards the UK government’s net zero targets. Both nitrogen and carbon cycles are essential ecosystem services, which define the fertility and resilience of our soils and food security. This project will benefit the UK farming sector and economy, with positive impacts on the general public through potential to reduce food prices and improved access to clean environment.