Unlocking bacterial potential to reduce farmland N2O emissions

Abstract Farmed soils contribute substantially to global warming by emitting N 2 O (ref. 1 ), and mitigation has proved difficult 2 . Several microbial nitrogen transformations produce N 2 O, but the only biological sink for N 2 O is the enzyme NosZ, catalysing the reduction of N 2 O to N 2 (ref. 3 ). Although strengthening the NosZ activity in soils would reduce N 2 O emissions, such bioengineering of the soil microbiota is considered challenging 4,5 . However, we have developed a technology to achieve this, using organic waste as a substrate and vector for N 2 O-respiring bacteria selected for their capacity to thrive in soil 6–8 . Here we have analysed the biokinetics of N 2 O reduction by our most…