The taming of the bacteria
EU-funded researchers have developed two cutting-edge software platforms that European crisis responders can now use to improve coordination, communication and preparedness. The platforms could help prevent catastrophes escalating, reduce economic losses and save lives.
Greenhouse gases like carbon dioxide (CO2) and nitrous oxide (N2O) trap warm air in the Earth’s atmosphere, which leads to higher temperatures and ultimately climate change. Nitrous oxide, better known as laughing gas, has a far more powerful greenhouse effect than CO2.
Farming and waste treatment are major sources of N2O, which contributes to around 10 % of global warming as well as ozone depletion. Increased use of synthetic nitrogen-based fertilisers is known to play a major role in rising N2O levels generated from the land and waste treatment.
But more research on microbes that produce and consume this gas is needed at the molecular level to develop better fertilisers in the future. Studies of land and waste management are also key to developing models, machinery and best practices to reduce this harmful greenhouse gas.
Scientists in the EU-funded NORA project took up this challenge, delving into the biochemical and microbial mysteries behind atmospheric N2O. They also developed more effective tools and a field robot to gather, process and analyse the huge volumes of data from land samples taken every day during different seasons.
“With better data and knowledge of the biochemistry, we were able to work on different levels to improve how fertilisers behave in contact with the land in different seasons and conditions,” says Norwegian University of Life Sciences’ Åsa Frostegård, who coordinated the NORA International Training
Network, a Marie Curie initiative which was the driving force behind the research. “For example, we found that simply by increasing the pH in soils which are too acidic, we can drastically reduce the N2O emissions.”
She adds that such actions would be in combination with better land management strategies, such as keeping soil aerated, and of course, not using too much fertiliser.
Back to bacteria for answers
N2O formation is a natural bacterial process. The NORA researchers set out to learn how some microorganisms in the soil, and one specific bacteria, are capable of both making and absorbing gas. Their findings, as reported by Euronews and the subject of several leading scientific publications, have helped to shed light on this poorly understood phenomenon.
The work by different teams, including a dozen young researchers on exchange between labs in Norway, Sweden, Germany, Holland, France and the UK, provides insight into potential reformulations for fertilisers and how they are applied in practice. But further work beyond the lifetime of the project and together with industry would be needed for that.
NORA studies focused more on improving basic understanding of N2O drivers — in particular how to coerce or “domesticate” bacteria to moderate themselves — at the molecular, biochemical level. The teams have isolated several of the main strains carrying the proteins involved in reducing or ‘consuming’
N2O, modelled their growth and characteristics, and stored all this in a biobank, which is a valuable resource for future evolutions of the research.
Their findings reveal a complex set of relationships between nitrogen levels recorded on farmland, but also in run-off and waste water, and the N2O gas emissions. Several regulatory mechanisms were revealed, which determine how effectively different so-called denitrifying bacteria act as sinks or sources for N2O.
For example, pH needs to be above a certain level, the researchers confirmed, and copper content should be high enough for the bacteria to make functional enzymes or ‘reductase’ that can reduce N2O. This evidence indicates that better pH management, copper content assessments, and the use of slow-release fertilisers are needed.
Switch to auto-mode
One of the big challenges facing researchers is the vast amounts of data that needs to be collected from diverse sampling locations, soil types and in a range of seasonal conditions; much of it carried out manually until NORA came along.
Realising the only way to make headway in this complex and multidisciplinary field of study would be to automate the collection, transfer, storage, sampling and analysis of the data using models also developed in the project.
They built a robot mounted with an articulated chamber containing sensors that pick up or sniff N2O emissions and relay the data directly for analysis in remotely located labs. The robot was showcased, along with other findings, during workshops and publications.
The project’s key results have been presented in scientific and mainstream media, including the ‘Futuris’ programme on Euronews. And knowledge has been shared thanks to the researcher exchanges and a summer school programme organised by the project. Several of the young scientists are now completing their PhDs on the back of the work carried out by NORA training network.
NORA has equipped a new generation of scientists with valuable cross-disciplinary skills in the vital field of nitrogen research, and it has benefited from a strong network of both academic and industrial partners.
Its early findings on soil and fertiliser management and practices signal immediate actions that European agricultural and environmental policymakers and legislators can take to reduce N2O emissions.