The urgent need to re-engineer nitrogen-efficient food production for the planet

One of the major "sustainability challenges" is to manage the unprece dented demands on agriculture and natural resources to match the increasing human population and consumption of nutritious protein and calories, while dramatically decreasing the environmental footprint in order to maintain the resilience of our planet. Global nitrogen pollution is of particular concern and is already beyond the Earth system's safe operating space. To meet the world's future food security, food production needs to be doubled by 2050 and as such will result in further increasing human pressure on the global nitrogen cycle. We argue that there is an urgent need for re-engineering of the anthropogenic nitrogen cycle in order to find a long-term sustainable solution. Firstly, the massive production of plant protein to be upgraded to animal protein has a far too heavy water and land-use footprint to be sustainable. It seriously threatens our freshwater resources by inducing harmful algal blooms through inefficient nutrient use. Secondly, it leads to large scale deforestation in bio diversity hotspots such as the Amazon and Sub-Saharan Africa. Third, the current production chain of plant and animal protein depends strongly on the implementation not only of fertilisers but also of pesticides, pharmaceuticals (e.g., antibiotics), and disinfectants, which indirectly are documented to create phenomena such as multi ple antibiotic-resistant bacteria and lower immunological defence and the presence and accumulation of antibiotic-resistant bacteria in agricultural soils. We argue that the line of direct protein production as animal feed or even for human consumption by using microorganisms is a welcome opportunity to alleviate the very significant burden that the contemporary food production systems have on our planet.