About this Research Topic
Nitrification is an integral part of the global biogeochemical nitrogen cycle and involves microbially-mediated conversions of ammonia into nitrite and further into nitrate. Nitrogen is essential for life on Earth, and the rapidly increasing anthropogenic input of reactive nitrogen into the environment has a profound impact on the nitrogen cycle. Every year approximately 120 Tg nitrogen fertiliser is applied globally, but a large portion of this nitrogen is lost through the activity of nitrifying microorganisms. This causes nitrogen leaching into aquatic ecosystems and increased emission of nitrous oxide, a very potent greenhouse gas. On the other side, nitrification is a pivotal step of biological wastewater treatment for the removal of excess nitrogen from sewage. Nitrification is a specialised metabolism performed by specific groups of bacteria and archaea, which are both ubiquitous and among the most numerous living organisms on the planet. Nitrifiers thus play a central role in determining the fate of nitrogen in aquatic, terrestrial and engineered environments.
Although nitrification has been studied for over a century, there have been major changes to our understanding of the process in the recent years, including the discoveries of ammonia oxidising archaea, complete ammonia oxidation to nitrate (comammox), revision of the enzymology of proteobacterial ammonia oxidisers, and new genera and metabolisms of nitrite oxidisers. The scope of this Research Topic is to cover the most recent advances in our understanding of the ecology, physiology, and biochemistry of ammonia and nitrite oxidising microorganisms. This Research Topic is aligned with the Sixth International Conference on Nitrification (ICoN6). Contributions are encouraged from both conference delegates and non-attending authors whose research falls within the scope of the Research Topic.
Authors are invited to submit both original research articles and reviews. The topics covered in this Research Topic include but are not limited to:
- Physiology, genomic, and post-genomic studies of nitrifying microorganisms
- Interactions of ammonia and nitrite oxidising microorganisms
- Nitrification in aquatic, terrestrial, and engineered ecosystems
- Applications and control of nitrifiers in drinking water and wastewater treatment, aquaculture, and agricultural management
- Novel metabolisms and pathways in nitrifying microorganisms
- Contributions of nitrifiers to greenhouse gas emissions and nitrogen flux
- Eco-physiological adaptations and niche differentiation of nitrifiers
- Interactions of nitrifiers with the heterotrophic community surrounding them
Keywords: Ammonia Oxidation, Nitrite Oxidation, Comammox, Nitrification, Nitrogen Cycle
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.