Who needs nitrogen? From biology to industry

November 17, 2025 •

4 min read

Approximately 78% of Earth's atmosphere consists of nitrogen, yet most living organisms cannot use it directly in its gaseous form. This critical element must first be converted into usable compounds through a process called nitrogen fixation before it can fuel life's most essential functions, making the answer to 'who needs nitrogen?' incredibly broad.

Quick Summary

Nitrogen is a fundamental building block for all life, essential for proteins, DNA, and plant growth. It is also a versatile industrial gas used in manufacturing, food preservation, and cryogenics due to its non-reactive nature.

Key Points

All life requires nitrogen: Nitrogen is a fundamental building block for amino acids, proteins, and the nucleic acids DNA and RNA, which carry genetic information.
Atmospheric nitrogen is largely unusable: Most organisms cannot directly process the abundant nitrogen gas ($N_2$) in the atmosphere; it must be converted into usable forms like nitrates and ammonium.
Plants get nitrogen through the nitrogen cycle: Nitrogen-fixing bacteria, lightning, and decomposition convert atmospheric nitrogen into soil compounds that plants can absorb through their roots.
Animals and humans consume nitrogen: Organisms higher up the food chain acquire their nitrogen by eating plants or other animals that have assimilated it.
Industries use nitrogen for inerting: Due to its non-reactive nature, nitrogen gas is widely used to displace oxygen and prevent oxidation in food packaging, electronics manufacturing, and fire suppression systems.
Liquid nitrogen is a powerful cryogenic agent: Its extremely low temperature makes liquid nitrogen ideal for rapid freezing in food processing, cryosurgery, and preserving biological samples.
Excess nitrogen causes environmental issues: Overuse of nitrogen fertilizers can lead to water pollution (eutrophication), which creates 'dead zones' that harm aquatic life.

The Fundamental Role of Nitrogen in All Living Things

Nitrogen is not merely an atmospheric filler; it is a chemical linchpin for all biological processes. This element is an integral component of numerous vital biomolecules that are the basis of life itself. Its biological importance is impossible to overstate.

Nitrogen's Role in Proteins and Nucleic Acids

At the cellular level, nitrogen is foundational. It forms a crucial part of the amino acids that link together to create proteins. These proteins perform a vast array of functions, from building tissue and muscle to acting as enzymes that catalyze biochemical reactions throughout the body. Similarly, nitrogen is a core component of the nitrogenous bases (adenine, guanine, cytosine, and thymine) that form the building blocks of DNA and RNA, the genetic blueprints for all life. Without a reliable source of usable nitrogen, organisms would be unable to synthesize these essential molecules, halting growth, reproduction, and all cellular function.

The Necessity of Nitrogen for Plants and the Nitrogen Cycle

For plants, nitrogen is a primary macronutrient vital for robust growth and development. A nitrogen-sufficient plant exhibits vigorous, dark green growth, largely because nitrogen is a key component of chlorophyll. Chlorophyll enables photosynthesis, the process by which plants convert sunlight into energy. Plants acquire usable nitrogen primarily from the soil in the form of nitrates ($NO{3}^{-}$) and ammonium ($NH{4}^{+}$). The global nitrogen cycle, a biogeochemical process, ensures that nitrogen circulates from the atmosphere to the earth and back again. This cycle involves several key stages:

Nitrogen Fixation: Specialized bacteria, often in the root nodules of legumes, convert atmospheric nitrogen gas ($N_2$) into ammonia ($NH_3$). Lightning can also fix nitrogen naturally.
Nitrification: Other soil bacteria convert ammonia into nitrites ($NO{2}^{-}$) and then nitrates ($NO{3}^{-}$), which plants can readily absorb.
Assimilation: Plants take up nitrates and ammonium, incorporating the nitrogen into their own organic compounds.
Ammonification: When plants and animals die or excrete waste, decomposers convert the organic nitrogen back into ammonium.
Denitrification: Bacteria in oxygen-poor soil environments convert nitrates back into atmospheric nitrogen gas, completing the cycle.

Industrial Applications of Nitrogen

Beyond its biological importance, nitrogen's chemical properties—particularly its inertness and cryogenic nature—make it indispensable to numerous industrial applications.

Industries That Rely on Inert Nitrogen Gas

Because nitrogen is largely unreactive, it is used to create inert atmospheres where oxygen-related reactions, like oxidation, are undesirable.

Food Packaging: Nitrogen gas is used in Modified Atmospheric Packaging (MAP) to replace oxygen inside food packages, which significantly extends the shelf life of perishable products by inhibiting microbial growth and spoilage.
Electronics Manufacturing: During the soldering process, nitrogen is used as an inert atmosphere to prevent oxidation and ensure the quality and integrity of solder joints.
Chemical and Petroleum Industries: Nitrogen is used for purging and blanketing storage tanks and pipelines, replacing flammable or reactive gases to prevent explosions and corrosion.
Fire Suppression: Nitrogen-based fire suppression systems displace oxygen to extinguish fires in enclosed spaces without damaging sensitive electronics, unlike water.

Cryogenic and High-Pressure Uses

Cryogenics: Liquid nitrogen (LN2), stored at an extremely low temperature of -196°C (-321°F), is a powerful cryogenic fluid. It's used to quickly freeze foods to preserve texture and flavor, for cryosurgery (the removal of abnormal tissue), and for the cryopreservation of biological samples like eggs and sperm.
High Pressure Applications: In the oil and gas industry, high-pressure nitrogen is injected into wells for stimulation or to maintain reservoir pressure. In the automotive and aerospace industries, nitrogen is used to inflate tires, as it maintains more stable pressure than air over a wide temperature range.

Nitrogen Needs: Biology vs. Industry


Aspect	Biological Needs	Industrial Needs
Form Used	Primarily fixed nitrogen compounds (e.g., nitrates, ammonium).	Inert nitrogen gas ($N_2$) and liquid nitrogen (LN2).
Primary Purpose	Essential building block for life's core molecules (proteins, DNA).	Non-reactive environment for safety and preservation; cryogenic freezing.
Source	Natural nitrogen cycle, including symbiotic bacteria.	Industrial processes like fractional distillation of liquid air.
Acquisition	Plant root uptake; animal consumption of plants and other animals.	On-site nitrogen generators or supplied in bulk by specialized companies.
Key Outcome	Growth, reproduction, energy transfer, and overall organism health.	Enhanced safety, extended shelf-life, and specialized processes.

Balancing the Nitrogen Demand

Today, human activity significantly influences the global nitrogen cycle, primarily through the industrial production and application of nitrogen fertilizers using the Haber-Bosch process. While this has dramatically increased food production, it also introduces substantial environmental challenges. Excessive use of nitrogen fertilizers can lead to significant nitrogen losses into the environment through leaching and runoff, which can cause eutrophication—the excessive growth of algae—in waterways. These algal blooms deplete oxygen, creating 'dead zones' that threaten aquatic life. Additionally, agricultural practices can release the potent greenhouse gas, nitrous oxide ($N_2O$), contributing to climate change. Therefore, implementing sustainable practices and improving nitrogen use efficiency in agriculture are critical for protecting our environment while still meeting global food demands.(https://www.cimmyt.org/news/nitrogen-in-agriculture/)

Conclusion

From the microscopic bacteria in soil to the advanced manufacturing facilities of the electronics and food industries, the need for nitrogen is profound and widespread. This colorless, odorless element forms the very fabric of life, serving as the essential building block for DNA and proteins. Simultaneously, its unreactive and cryogenic properties make it a workhorse for modern technology, ensuring safety, quality, and efficiency in a myriad of applications. Understanding the complex ways in which we use and manage nitrogen—both biologically and industrially—is crucial for sustaining life on Earth and responsibly navigating the environmental consequences of its use.

Frequently Asked Questions

Atmospheric nitrogen gas ($N_2$) is held together by a very strong triple bond that most organisms cannot break down. It must first be converted, or 'fixed,' into more reactive compounds like nitrates or ammonium to be used biologically.

Plants absorb nitrogen compounds from the soil through their roots. These compounds are made available primarily by specialized nitrogen-fixing bacteria, which convert atmospheric nitrogen into nitrates and ammonium.

The nitrogen cycle is the natural process by which nitrogen is circulated through the atmosphere, soil, water, and living organisms. It involves stages like nitrogen fixation, nitrification, assimilation, ammonification, and denitrification.

Unlike plants and some bacteria, humans and animals cannot fix nitrogen. They obtain it by consuming plants or other animals, ingesting the organic compounds that have already incorporated nitrogen.

Nitrogen gas is used to replace oxygen in food packaging in a process called Modified Atmospheric Packaging (MAP). This prevents oxidation and inhibits the growth of bacteria and other spoilage organisms, extending the product's shelf life.

Liquid nitrogen is primarily used as a cryogenic coolant due to its extremely low temperature. Applications include freezing foods, cryosurgery, and the cryopreservation of biological samples.

Overuse of nitrogen fertilizers in agriculture is a major source of environmental pollution. Excess nitrogen can run off into waterways, causing eutrophication and creating 'dead zones' where aquatic life cannot survive.

Yes. While plants need nitrogen, too much can be toxic. Excessive nitrogen can lead to overgrowth of leafy biomass at the expense of proper root development, and in extreme cases, can poison animals that eat the plants.