Rhizobia-legume symbiosis is the main route for sustainable nitrogen to contribute to soil fertility. During symbiosis, legumes develop nodules hosting endosymbiotic bacteria expressing nitrogenase, a unique iron and molybdenum metalloenzyme that transforms atmospheric nitrogen into ammonia that can be utilized by plants. This is important for society because would help us to produce nutritive protein resources (pulses) in a sustainable way, this is without using polluting nitrogen fertilizers. Since fertilizers significantly contribute to the rise in food prices observed in recent years, this would have second-derived benefits to our society. Interestingly, iron is not only essential for bacteria but for all organisms on our planet. This includes plants, animals, and ourselves. Probably you or someone closer to you suffer iron deficiency or anemia, as 2 billion people are affected by it worldwide.
The EU-funded IronFeRhizo project has combined biochemical and molecular biology techniques to determine how much iron is required by nitrogen-fixing bacteria, which genes are required in its transport into the cell, and how much is used to metallate the nitrogenase and other metalloproteins in order to increase their capacity to fix atmospheric nitrogen and sustain higher productivities in the field. Moreover, the techniques developed will facilitate research into mineral nutrition in other organisms (bacteria and plants) and would help us to intervene in our food chains to increase the amount of iron that ends up in our plates.
