In a recent study published in Proceedings of the National Academy of Sciences, a group of scientists used single-cell organisms, called archaea, to better determine changes in ancient sea temperatures and conditions. Archaea are of neither the animal kingdom nor are they of a bacterial nature, but instead are tiny organisms found in ancient sediments.
While the method of studying these microscopic clues isn't necessarily a new one, scientists are now getting much closer to identifying just what proteins were present during the oceans' temperature changes. The information derived from the archaea could also detail if any other environmental factors played a role as well.
Paula Welander, Ph.D., associate professor of Earth system science at Stanford University and co-author of the study, says that a better understanding of the organisms will assist in determining "ancient global temperatures, and impact our understanding of past temperature variability and Earth system dynamics."
Archaea hold climatic clues about environmental changes in fatty membranes that undergo transformations due to stress; this also includes environmental stress. The lipids in these membranes are known to change from being loose with a double layer to a much tighter, single-layered membrane. The membranes are also subject to developing hydrocarbon rings on their bodies when exposed to certain types of proteins along with the previously mentioned stressors.
In this particular study, Dr. Welander and her team experimented with an archaea called Sulfolobus acidocaldarius to determine exactly what types of proteins cause hydrocarbon rings to form on the body of the organisms.
As a result of the experiment, the team identified two proteins that essentially led to the growth of the rings, GrsA and GrsB. After comparison with other archaea, such as Thaumarchaeota, the team confirmed that the rings formed were in fact due to oceanic temperature changes.
"People have been looking for these proteins for 40 years," Welander said in a press release regarding the study. "With that critical information now in hand, we can start to constrain some of the uncertainty about this particular archaea-based paleotemperature proxy."
Dr. Welander also explained that the team's findings in the experiments will not only help better determine ancient oceanic temperature changes, but will also be beneficial in the discovery of new drugs as well as scientific materials.
"Microbes invent all kinds of weird biochemistry to do all kinds of weird reactions," Welander said. "Anytime you can expand that chemistry of what is possible, it's really exciting from just a basic science perspective."
