1. Unlocking bacterial potential to reduce farmland N 2 O emissions.
- Author
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Hiis EG, Vick SHW, Molstad L, Røsdal K, Jonassen KR, Winiwarter W, and Bakken LR
- Subjects
- Bacterial Proteins metabolism, Biofuels supply & distribution, Flavobacteriaceae cytology, Flavobacteriaceae growth & development, Flavobacteriaceae metabolism, Nitrogen metabolism, Europe, Farms, Global Warming prevention & control, Nitrous Oxide metabolism, Nitrous Oxide analysis, Soil chemistry, Soil Microbiology, Crop Production methods, Crop Production trends
- Abstract
Farmed soils contribute substantially to global warming by emitting N
2 O (ref.1 ), and mitigation has proved difficult2 . Several microbial nitrogen transformations produce N2 O, but the only biological sink for N2 O is the enzyme NosZ, catalysing the reduction of N2 O to N2 (ref.3 ). Although strengthening the NosZ activity in soils would reduce N2 O emissions, such bioengineering of the soil microbiota is considered challenging4,5 . However, we have developed a technology to achieve this, using organic waste as a substrate and vector for N2 O-respiring bacteria selected for their capacity to thrive in soil6-8 . Here we have analysed the biokinetics of N2 O reduction by our most promising N2 O-respiring bacterium, Cloacibacterium sp. CB-01, its survival in soil and its effect on N2 O emissions in field experiments. Fertilization with waste from biogas production, in which CB-01 had grown aerobically to about 6 × 109 cells per millilitre, reduced N2 O emissions by 50-95%, depending on soil type. The strong and long-lasting effect of CB-01 is ascribed to its tenacity in soil, rather than its biokinetic parameters, which were inferior to those of other strains of N2 O-respiring bacteria. Scaling our data up to the European level, we find that national anthropogenic N2 O emissions could be reduced by 5-20%, and more if including other organic wastes. This opens an avenue for cost-effective reduction of N2 O emissions for which other mitigation options are lacking at present., (© 2024. The Author(s).)- Published
- 2024
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