Nitrogenase
The enzyme that reduces N2 to ammonia. Oxygen-sensitive, energetically expensive.
Darker cells mean a higher score for this topic on that metric.
Familiarity40
Medical weight10
Benefit90
Risk8
Research60
Live debate15
LessMore
Last reviewed Sources & creditsMedia creditsMethodology
Quick answers
Where should I start with Nitrogen cycle?
Read Identity → How they live → Body & health, then use compare rails.
Is this page advice for Nitrogen cycle?
Public-health education — not a care plan, prescription, or outbreak briefing.
What does the local lens add?
It names everyday desks for Beneficial allies before English norms look universal.
Are the scores a ranking of Nitrogen cycle?
No — editorial 0–100 browsing aids inside this atlas only.
How do I compare Nitrogen cycle to neighbours?
Use related cards and best-of / quiz rails after the first three chapters.
Which chapter is densest?
How they live and Body & health carry mechanisms; skim Identity first.
A clover nodule is a low-oxygen factory for nitrogenase. A flooded field can denitrify surplus nitrate back to gas.
Anammox (described in the 1990s) combines ammonium and nitrite to N2 — now a wastewater idea, not a home experiment.
Parts
Root nodules
Legume homes for rhizobia. A plant-microbe contract, not a pathogen protocol.
Ammonia oxidisers
Bacteria and some archaea start nitrification. Teaching names include Nitrosomonas.
Nitrate
A mobile ion plants can drink — and rain can wash to rivers.
Denitrifiers
Anaerobes breathe nitrate and may release N2 or N2O.
Anammox planctomycetes
A 1990s surprise pathway now engineered into some treatment plants at concept level.
Life cycle
1Fix
N2 becomes ammonia inside specialists. Lightning does a tiny extra share.
2Build or mineralise
Ammonia enters amino acids, then returns when tissues rot.
3Nitrify
Ammonia becomes nitrite then nitrate where oxygen allows.
4Return to air
Denitrification or anammox closes the loop. Some N2O leaks aside.
This page names the jobs. It does not tell you how to grow the workers.
Keep exploring
More in Beneficial allies
Gut microbiome
A diverse intestinal community fed by fibre — not a single ideal species list and not a wellness shop.
Familiarity 88Probiotics
Live microbes in food or capsules — strain-specific guests, not a whole microbiome and not medical advice.
Familiarity 90Fermentation
Microbes turning food into kimchi, doenjang, yoghurt and other living crafts — chemistry plus culture.
Familiarity 85Skin microbiome
A site-specific living film — oily, moist and dry neighbourhoods, not a sterile wrapper.
Familiarity 62Soil microbes
The hidden workforce of land — decomposers, mycorrhizae and a mostly uncultured majority.
Familiarity 48