{"id":625627,"date":"2026-09-15T19:42:10","date_gmt":"2026-09-15T19:42:10","guid":{"rendered":"https:\/\/www.newsbeep.com\/ie\/625627\/"},"modified":"2026-09-15T19:42:10","modified_gmt":"2026-09-15T19:42:10","slug":"molecular-insight-into-biological-nitrogen-fixation-close-to-the-boiling-point","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ie\/625627\/","title":{"rendered":"Molecular insight into biological nitrogen fixation close to the boiling point"},"content":{"rendered":"

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\"Look<\/p>\n

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image:\u00a0<\/p>\n

Illustration of the core of the heat-stable nitrogenase from a deep-sea microorganism, showing the metallocofactor which breaks nitrogen gas into ammonia.\u00a0<\/p>\n

view more\u00a0<\/a><\/p>\n

Credit: Illustration by Benjamin Large, Sc\u00b7EYE\u00b7nce \/ Max Planck Institute for Marine Microbiology,<\/p>\n

To the point<\/p>\n

\tA remarkable nitrogenase:\u00a0Scientists have purified a nitrogen-fixing enzyme from a deep-sea microorganism that shows extreme heat-stability and is possibly of ancient origin.
\n\tA new state:\u00a0The molybdenum-containing enzyme has been captured in a \u201cturnover\u201d state, highlighting a universal mechanistic principle among nitrogenases.
\n\tA promising outlook:\u00a0A better understanding of the nitrogen-fixation reaction holds great potential to tackle the climate crisis and environmental problems.\u00a0\u00a0\u00a0<\/p>\n

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Breaking one of nature’s toughest chemical bonds<\/p>\n

Microorganisms can do remarkable things \u2013 for example nitrogen fixation, the conversion of nitrogen gas (N\u2082) into a form that organisms can use. Although nitrogen gas makes up around 78 per cent of Earth’s atmosphere, plants and animals can not directly use it. The two nitrogen atoms are held together by superglue: a chemical triple bond. But some microorganisms have a superpower: They can fix the nitrogen by breaking these bonds and converting N\u2082 into ammonia, which can then be used to build biological molecules. One such superhero is the deep-sea archaeon\u00a0Methanocaldococcus infernus. This microorganism lives in marine volcanic areas, where temperatures of vent fluids can exceed the boiling point of water.\u00a0<\/p>\n

That sparked curiosity of the scientists from Tristan Wagner\u2019s laboratory at the Max Planck Institute for Marine Microbiology in Bremen. They \u201ctamed\u201d this microorganism, forcing it to fix N2\u00a0even at temperatures above 90 \u00b0C. \u201cHow do they do it, in such heat? And how can the enzyme splitting the N2\u00a0triple bond work under these conditions?\u201d Wagner asked himself.\u00a0<\/p>\n

The enzyme that provides the superpower of fixing N2\u00a0is called nitrogenase, an enzyme which contains the most complicated metallocofactor known in biology. Metallocofactors are metallic helper molecules, bound to an enzyme and essential for its function. The best-studied and most performant nitrogenases have a metallocofactor containing molybdenum, but they also exist in vanadium- and iron-only forms. How these different forms are related to one another and exactly how their metal centres enable them to break the N\u2082 triple bond remains an active area of research.<\/p>\n

A remarkable nitrogenase built for extreme conditions<\/p>\n

\u201cThe nitrogenase found in\u00a0Methanocaldococcus infernus\u00a0is remarkable because it seems to share traits of the molybdenum, vanadium and iron forms. This type of nitrogenase could be similar to a common nitrogenase-ancestor, the ancient system all of them evolved from. Thus, it could deliver common principles in the nitrogenase reaction,\u201d says Wagner.\u00a0<\/p>\n

The researchers were able to isolate the nitrogenase directly from the microbe. This enzyme proved exceptionally stable at high temperatures, as the protein starts to fall apart only at 90 \u00b0C, and some of it even survived at 98 \u00b0C.\u00a0<\/p>\n

\u201cThis proves that this enzyme is designed to function under conditions in which most proteins would rapidly decay, like egg white cooked in hot water\u201d, says first author Nevena Masla\u0107 from the Max Planck Institute for Marine Microbiology. \u201cIt is not active at room temperature. Rather, we show that it only produces ammonia at high temperatures. Its extreme stability allowed us to study states of the nitrogenase that are usually difficult to capture.\u201d<\/p>\n

State-of-the-art methods for a molecular dissection\u00a0<\/p>\n

Getting a detailed picture of this nitrogenase did not require the researchers to travel to the deep sea, but it did require a tour de force combining microbial physiology, native enzyme purification, biochemistry and structural biology\u2014all under strictly oxygen-free conditions to avoid irreversible damage to its metallocofactors.\u00a0<\/p>\n

For this, the researchers obtained the enzyme in a crystal form and studied it at the Institut de Biologie Structurale in Grenoble, France. Here, they used the on-site synchrotron\u2014a circular particle accelerator producing powerful X-rays. First, the scientists unveiled the molecular structure of the nitrogenase. They achieved a near-atomic-resolution view of the simplest nitrogenase known to date. It combines structural features of all three known nitrogenase families\u2014molybdenum-, vanadium- and iron-only nitrogenases. This supports the idea that ancestral nitrogenases may have been more similar to this archaeal enzyme than to their bacterial counterparts. Next, the researchers wanted to ensure that the nitrogenase contained the molybdenum metallocofactor. \u201cOur search for the molybdenum was technically extremely challenging and required the experts at the synchrotron to push their instrument to its absolute limits\u201d, says Wagner.\u00a0<\/p>\n

In the end, the measurement not only delivered the typical molybdenum signal but held another surprise: \u201cWe were stunned to look at a so far unobserved state in a molybdenum-containing nitrogenase!\u201d\u00a0Until now, the so-called \u201cturnover\u201d state, potentially showing an intermediate step in the reaction, has been captured solely in the vanadium and iron-only forms. Observing\u00a0this state also in a molybdenum enzyme suggests that nitrogenase universally follows the same pattern to break down N2.\u00a0<\/p>\n

From deep-sea chemistry to future biotechnology<\/p>\n

A better understanding of nitrogen fixation is important for much more than just the deep sea. Nitrogen-fixing microorganisms such as\u00a0M. infernus\u00a0not only make nitrogen available in the form of ammonia, but they are also major players in Earth’s carbon cycle by generating half of the methane we find in the atmosphere. In the future, such organisms could potentially be explored as biological platforms for converting gases into useful products, including methane and ammonia, using green hydrogen as an energy source.<\/p>\n

\u201cAnd what if crops could one day obtain nitrogen directly from atmospheric N\u2082?\u201d Wagner speculates. That could make agriculture less dependent on industrial fertilisers. Today, fertiliser production through the Haber\u2013Bosch process requires substantial energy and is associated with greenhouse gas emissions, while excessive fertiliser use contributes to eutrophication and other environmental problems. \u201cFor now, the study provides something more fundamental: an updated molecular view of one of biology’s most remarkable chemical reactions.\u201d<\/p>\n

Journal<\/p>\n

Nature Communications<\/p>\n

Article Title<\/p>\n

Molecular basis of N\u2082 fixation in a hyperthermophilic archaeon<\/p>\n

Article Publication Date<\/p>\n

8-Sep-2026<\/p>\n

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.<\/p>\n","protected":false},"excerpt":{"rendered":"image:\u00a0 Illustration of the core of the heat-stable nitrogenase from a deep-sea microorganism, showing the metallocofactor which breaks…\n","protected":false},"author":2,"featured_media":625628,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[61,60,82],"class_list":["post-625627","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-ie","tag-ireland","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/625627","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/comments?post=625627"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/625627\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media\/625628"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media?parent=625627"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/categories?post=625627"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/tags?post=625627"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}