Hydrogen energy at the root of life

Related Articles

Related Articles

Since the discovery of submarine hydrothermal vents around 40 years ago, these natural chemical reactors have been a focus for evolutionary researchers searching for the origin of life.

The vents emit hot water containing minerals, including simple but reactive chemical substances such as hydrogen gas (H2) and carbon dioxide (CO2). Conditions like these could have resulted in the very first biochemical reactions, and thus in the emergence of the first free living cells.

The starting point of such primitive metabolism of the first microbes is carbon dioxide and hydrogen gas. Microbes that live from these substances first convert the two gases into formic acid (formate), acetate and pyruvate (salts of acetic acid and pyruvic acid). They then use these to make all of their organic material through a dense roadmap of complicated reactions. What chemist Dr. Martina Preiner from the Institute of Molecular Evolution of Heinrich Heine University Düsseldorf (HHU) and an international team now show is that precisely these basic building blocks of life emerge all by themselves in a lab environment when H2 and CO2 are left to react in the presence of simple minerals in hydrothermal conditions.

For the last 20 years, Prof. Dr. William Martin, Head of the Institute of Molecular Evolution, has been cataloguing the many parallels between metal-catalysed reactions in metabolism and chemical reactions at hydrothermal vents. Prof. Martin says: “These reactions based on H2 and CO2 that reflect the origins of the first biochemical processes can now be simulated in a lab in Düsseldorf, allowing us to mimic the earliest development phases of life.”

Together with researchers from the Max Planck Institute for Coal Research in Mülheim/Ruhr, the University of Strasbourg and the National Institute of Advanced Industrial Science and Technology in Japan, Dr. Preiner has simulated these very simple reactions in a lab environment. They have been able to demonstrate that H2 and CO2 organize into formate, acetate and pyruvate overnight at temperatures of 100 degrees Celsius as long as a few simple mineral catalysts are present – catalysts that themselves are formed in hydrothermal vents. Martina Preiner emphasises the fact that no microbial metabolism is needed. “The chemical reactions are surprisingly simple. The main products created are exactly those used by the earliest cells as a basis for their further metabolism.”

Dr. Harun Tüysüz and his team from the Max Planck Institute in Mülheim have designed nanostructured solid catalysts for the experiments: “We observe a distinct structure-activity relationship of the solid catalysts for CO2 reduction in the origins of life context.”


Subscribe to more articles like this by following our Google Discovery feed - Click the follow button on your desktop or the star button on mobile. Subscribe

Serendipity would have it that two other working groups were also studying similar processes. A team of Strasbourg-based chemists working under Prof. Dr. Joseph Moran and Dr. Kamila Muchowska were using metallic iron instead of H2. The Japanese team working with microbiologist Dr. Kensuke Igarashi was examining reactions of H2 and CO2 over iron-sulphide catalysts. All of the groups observed the same products. Prof. Moran says: “Metabolism appears to have developed in a surprisingly natural way”.

The origins of life leads to a ‘chicken or egg’ problem. In addition to the simple CO2-H2 reactions, cells have to form a large number of more complex modules in order to grow and function. Modern cells generally feature proteins as catalysts, the construction of which is encoded in the genes. But what came first, the proteins or the nucleic acids? The study now published suggests that they were preceded in evolution by reactions catalysed by metals and minerals, and that both proteins and nucleic acids emerged from those reactions. The metals found in modern proteins are relicts of these biochemical beginnings.

The study also sheds important light on the classical problem in origin of life research: What energy was available to the earliest life forms? Preiner and colleagues showed that the reactions of H2 with CO2 under the same conditions as those prevalent in hydrothermal vents also release energy. When producing simple compounds such as acetate, enough energy is created to allow primitive microbes to fuel their further metabolism.

This means that the fuel for original cells was hydrogen, which was formed in huge quantities in submarine environments when the Earth was young and continues to be formed today. Not only is hydrogen the cleanest of all energy forms – producing just water when combusted – it may also be the spark that created life itself. The decisive factors were having the right conditions and the right catalysts in place.

HEINRICH-HEINE UNIVERSITY DUESSELDORF

Header Image – Hydrothermal vent in the ‘Lost City’ Hydrothermal Field in the Atlantic. Credit : Susan Lang, U. of SC. / NSF / ROV Jason / 2018 © Woods Hole Oceanographic Institution

- Advertisement -

Download the HeritageDaily mobile application on iOS and Android

More on this topic

LATEST NEWS

Volubilis – The Ancient Berber City

Volubilis is an archaeological site and ancient Berber city that many archaeologists believe was the capital of the Kingdom of Mauretania.

Pella – Birthplace of Alexander The Great

Pella is an archaeological site and the historical capital of the ancient kingdom of Macedon.

New Argentine fossils uncover history of celebrated conifer group

Newly unearthed, surprisingly well-preserved conifer fossils from Patagonia, Argentina, show that an endangered and celebrated group of tropical West Pacific trees has roots in the ancient supercontinent that once comprised Australia, Antarctica and South America, according to an international team of researchers.

High-tech CT reveals ancient evolutionary adaptation of extinct crocodylomorphs

The tree of life is rich in examples of species that changed from living in water to a land-based existence.

Fish fossils become buried treasure

Rare metals crucial to green industries turn out to have a surprising origin. Ancient global climate change and certain kinds of undersea geology drove fish populations to specific locations.

Archaeologists Discover Viking Toilet in Denmark

Archaeologists excavating a settlement on the Stevns Peninsula in Denmark suggests they have discovered a toilet from the Viking Age.

Innovation by ancient farmers adds to biodiversity of the Amazon, study shows

Innovation by ancient farmers to improve soil fertility continues to have an impact on the biodiversity of the Amazon, a major new study shows.

Lost Shiva Temple Buried in Sand Discovered by Local Villagers

Villagers from the Perumallapadu village in the Pradesh’s Nellore district of India have unearthed the 300-year-old Temple of Nageswara Swamy on the banks of the Penna River.

Ma’rib – Capital of the Kingdom of Saba

Ma'rib is an archaeological site and former capital of the ancient kingdom of Saba in modern-day Ma'rib in Yemen

Giant Egg Discovered in Antarctica Belonged to Marine Reptile

A large fossil discovered in Antarctica by Chilean researchers in 2011 has been found to be a giant, soft-shell egg from 66 million years ago.

Popular stories