A chimney structure is located more than 8,800 feet below the sea's surface at the submarine boundary of the Pacific and Gorda tectonic plates. The Ocean Exploration Trust is a credit.
Complex communities of life can be found in the underwater fissures of the ocean floor. The hot fluids arelched into the cold water, creating the chemical forces necessary for the small organisms to live.
Jeffrey Dick and Everett Shock have found that certain organisms can thrive in certain areas of the ocean. They have opened up new possibilities for life in the dark at the bottom of the oceans and throughout the solar system. Their results have been published.
When organisms get energy out of the food they eat, they do so through a process called cellular respiration, where there is an intake of oxygen and the release of carbon dioxide. The instability in our food is harnessed by our cells to grow and reproduce, a process called biosynthesis.
The conditions for life are vastly different for organisms living on the ocean floor.
"On land, in the oxygen-rich atmosphere of Earth, it is familiar to many people that making the molecule of life requires energy," said co-author Shock of Arizona State University's School of Earth and Space Exploration. The hot fluids mix with the cold water to create conditions where life releases energy.
In deep-sea environments, organisms thrive near vents. The research led by Shock found that the production of basic cellular building blocks, like sugars and amino acids, is more favorable in areas with low-silica rocks.
Cells need to form larger molecule, or biomacromolecules, besides the basic building blocks. The most abundant of these molecule in cells are the genes, and the polymerization reaction requires energy in almost all conceivable environments.
Dick is a researcher in the School of Geoscience and was a graduate student at the time of this research. There are two opposing energy flows, one of which is the release of energy by the synthesis of basic building blocks.
What Dick and Shock wanted to know was what happens when you add them up, and what the results are.
They used a combination of theory and data to solve the problem.
They used a model called "group additivity" to account for the specific amino acids in the proteins. They used the entire genome of a well-studied vent organisms called Methanocaldococcus jannaschii for the data.
They were able to show that the energy in the mixing zone of the ultramafic-hosted vent is released when the overall synthesis of almost all the proteins in the genome is done. In a basalt-hosted system, the synthesis of proteins is not favorable.
Dick said that the finding provides a new perspective on the ecology of certain organisms in certain environments. Microbial ecology studies show that methanogens are more abundant in ultramafic-hosted vent systems than in basalt-hosted systems. The favorable energetics of synthesis are consistent with the distribution.
Dick and Shock are looking at ways to use these calculations across the tree of life to provide a link between the chemistry of the soil and the evolution of the genome.
"As we explore, we're reminded that we should never equate where we live to what's good in life," Shock said.
Jeffrey M. Dick and his co-authors wrote a paper about the release of energy during the process of making a molecule. The DOI is 10.1029/2021JG006436.
There are new possibilities for life at the bottom of Earth's ocean and possibly in oceans on other planets.
The document is copyrighted. Any fair dealing for the purpose of private study or research cannot be reproduced without written permission. The content is not intended to be used for anything other than information purposes.
