About this Research Topic
Nitrogen is an essential component of proteins and DNA in all living forms. Although Nitrogen gas (N₂) makes up 78% of the air, this form is very inert and cannot be used by plants or animals. Therefore plant biomass and productivity of many ecosystems are limited by the availability of reactive nitrogen (reduced or oxidized forms of Nitrogen). Over the last century synthetic nitrogen fertilizers have dramatically increased crop yields and allowed an unprecedented growth of the world population. In fact, fertilizer N currently accounts for nearly half the protein in the human diet. Yet at least 50% of applied nitrogen is lost to the environment in water run-off from fields, animal waste and gas emissions from soil microbe metabolism. Thus, the biogeochemical N cycle has been heavily perturbed by an unprecedented accumulation of reactive nitrogen that threatens the quality of air, soils and waters, and negatively impacts human health, biodiversity and climate.
Diverse local, regional and global strategies have been proposed to be adopted in order to reduce our N footprint, including changes in dietary habits (i.e. demitarian diet), reduce food waste and recycling of waste N, in addition to efforts to a more efficient use of nitrogen on farms. However, many of those strategies seem to forget two main realities: first is that N fertilization is very unequally applied, with excess N fertilizer used at great environmental cost in many (rich) agricultural systems, whereas too little N is used in poorest countries where food security is jeopardized. Second, that diverse microbes (bacteria and fungi) are protagonists in all the main reactions of the Nitrogen biogeochemical cycle and, therefore, microbial biotechnologies can contribute many solutions to the N problem. Processes like nitrification, ammonification and denitrification in soils and waters are mainly carried out by fungi and bacteria, whereas biological nitrogen fixation can be exclusively performed by certain water-, soil-, animal- or plant-associated bacteria that produce the enzyme nitrogenase. Thus, bringing reactive nitrogen back to planet safety boundaries while ensuring sufficient protein to feed a growing human population, must also consider actions to harnessing N-cycle microbes.
This Research Topic focuses on the biotechnology of microbes and microbial processes which directly or indirectly contribute to reduce nitrogen pollution and therefore to alleviate the N problem at local and/or global scales.
Articles to be published in this Topic (original research articles, commentaries, opinion papers, reviews) should contribute to understanding microbial processes within the Nitrogen cycle and to harnessing microbes for nitrogen-sustainable production of food and other goods (i.e. biofuels), as well as for direct alleviation of Nitrogen pollution (i.e. nitrogen recycling).
Articles should investigate or discuss the following issues:
- Novel procedures for production, application and traceability of more efficient Nitrogen Biofertilizers.
- Role of microbial symbioses in the nitrogen cycle.
- Engineering Nitrogen-fixing systems: novel nitrogen-fixing microbes, nitrogen-fixing plants, new nitrogen-fixing symbioses.
- Industrial uses of Nitrogen fixers
- Microbial recycling of reactive Nitrogen
- Denitrification and environmental protection
- Ammonification/Nitrification and environmental protection
- Anammox applications
Keywords: nitrogen oxides, environmental pollution, climate change, sustainable food production
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.