Nitrogenase
The enzyme that reduces N2 to ammonia. Oxygen-sensitive, energetically expensive.
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.
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