What does denitrify mean?
Denitrify means to remove nitrogen or nitrogen compounds from a substance, and it is most commonly used in soil science and microbiology to describe a vital step in the nitrogen cycle. In waterlogged or oxygen-poor soils, specialized anaerobic bacteria denitrify nitrates — converting them into gaseous forms of nitrogen such as N₂O and N₂ — which then escape back into the atmosphere. This process matters enormously in agriculture and ecology: while it helps cleanse waterways of excess fertilizer runoff, it also depletes soils of plant-available nitrogen and can release nitrous oxide, a potent greenhouse gas. Beyond biology, denitrify has a broader chemical sense of removing nitrogen from any compound. The word derives from the prefix de- plus 'nitrogen' plus the suffix -ify, and it belongs to a family of technical terms including denitrification, denitrifying, and denitrifier. It remains firmly scientific in register, rarely encountered outside technical writing and classroom discussion.
verbTo remove nitrogen or nitrogen compounds from something; in soil science, to convert nitrates in soil into gaseous nitrogen through the action of denitrifying bacteria, returning nitrogen to the atmosphere.
- (of bacteria and natural processes) to reduce nitrates in soil or water to nitrogen gas, releasing it into the atmosphere
- (chemistry) to remove nitrogen from a substance or compound
"Waterlogged soils tend to denitrify rapidly, releasing valuable nitrates back into the air as nitrogen gas."
"Anaerobic microbes in the wetland denitrify the runoff, stripping excess nitrates before they reach the river."
"In the lab, the chemists sought to denitrify the compound without degrading its structure."
The bacteria that denitrify soil are quietly undoing farmers' work — converting expensive fertilizer straight back into the air.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of denitrify
Denitrify was formed in English from the prefix de-, indicating removal, combined with 'nitrogen' and the verb-forming suffix -ify. Its components trace back further: 'nitrogen' itself was coined in the late eighteenth century from Greek 'nitron' (saltpetre) via French, reflecting the element's presence in nitrates. The related verb nitrify predates it, and denitrify emerged alongside the rise of modern agricultural and microbiological science as researchers identified bacterial processes that return soil nitrates to the atmosphere. Its derivatives include denitrification, denitrifier, and denitrifying.
Related word forms
How denitrify is actually used
A technical term used chiefly in soil science, microbiology, environmental science, and chemistry. It typically appears in formal or scientific registers rather than everyday conversation, often with bacteria, microbes, or soils as the subject.
Easily confused with denitrify
Nitrify means to add or combine nitrogen (or convert ammonia into nitrates), while denitrify means to remove it.