DEC 29, 2018 1:41 PM PST

A Microbe's Membrane Protects It From Extreme Environments

WRITTEN BY: Carmen Leitch

There are microscopic organisms called archaea living in some of Earth’s most intense environments, like hydrothermal vents deep in the ocean, boiling hot springs or volcanic craters. So how are they able to not only survive, but thrive there? Researchers at Stanford University have discovered a protein that helps tough archaea to form a protective membrane that shields them from acidic environments. Their findings have been reported in the Proceedings of the National Academy of Sciences (PNAS). Learn more about microbes that love extreme environments and the researchers that study them from the video.

It’s known that archaea, which occupy their own branch on the tree of life, have a unique membrane surrounding them, which is different from the ones found in plants, bacteria, or animals. Now this team has provided direct evidence of a protein that helps generate a lipid-linked structure in a species called Sulfolobus acidocaldarius.

"Our model is that this organism evolved the ability to make these membranes because it lives in an environment where the acidity changes," explained study co-author Paula Welander, an assistant professor of Earth system science at Stanford's School of Earth, Energy & Environmental Sciences (Stanford Earth). "This is the first time we've actually linked some part of a lipid to an environmental condition in archaea."

Researchers can look to the fossil record to learn more about biological membranes from long ago. This work will help researchers identify molecular features of other fossils, and provide insight into the evolution of Earth’s organisms.

This particular microbe is found in hot springs that can reach over 200 degrees, and have varying levels of acidity, as well as other hot and cold environments. It has unusual chemistry, which drew the attention of Welander. Archaea don’t have outer walls of cellulose like plants and fungi, nor do they have the same chemicals as bacteria, and her research group wanted to know more.

"I think we forget that some things just haven't been done yet - I've been finding that a lot ever since I stepped into the geobiology world," Welander said. "There are so many questions out there that we just need the basic knowledge of, such as, 'What is the protein that's doing this? Does this membrane structure really do what we're saying it does?'"

The team began by identifying genes in  S. acidocaldarius that were likely to be involved in the production of a molecule called calditol. Previous work had indicated it was a part of archaea’s membrane. One at a time, they inactivated genes, until the lack of one gene produced S. acidocaldarius without calditol. The mutant could survive high temperatures, but could not tolerate acidity. That suggested that calditol is critical to their unique membrane, which protects from acidity.

"There are certain things about archaea that are different, like the lipids," Welander said. "Archaea are a big area of research now because they are this different domain that we want to study, and understand - and they're really cool."

Learn more about archaea from the video.

Sources: AAAS/Eurekalert! via Stanford's School of Earth, Energy & Environmental Sciences, PNAS

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
MAY 02, 2021
Microbiology
Fasting Alters Gut Microbiota, Lowering Blood Pressure
MAY 02, 2021
Fasting Alters Gut Microbiota, Lowering Blood Pressure
Increasingly, microbes in the gut are being linked to human health and disease. New research has suggested that disrupti ...
MAY 04, 2021
Cell & Molecular Biology
A Potential Weakness in SARS-CoV-2 is Caught on Video
MAY 04, 2021
A Potential Weakness in SARS-CoV-2 is Caught on Video
You can see the spike protein of the virus in action in this video.
MAY 14, 2021
Earth & The Environment
New species of cyanobacteria discovered
MAY 14, 2021
New species of cyanobacteria discovered
A new study published in Current Biology details the finding of a previously unidentified species of cyanobacteria. The ...
MAY 25, 2021
Microbiology
Concern Grows About Emerging H5N8 Flu Virus
MAY 25, 2021
Concern Grows About Emerging H5N8 Flu Virus
Though suspected outbreaks have been documented since 1878, the first confirmed outbreak of bird flu, a highly pathogeni ...
MAY 26, 2021
Coronavirus
Why Did the COVID-19 Lab Leak Theory Suddenly Gain Traction?
MAY 26, 2021
Why Did the COVID-19 Lab Leak Theory Suddenly Gain Traction?
Since the onset of the COVID-19 pandemic, there has been little doubt that the virus emerged somewhere in or around Wuha ...
MAY 30, 2021
Microbiology
The Mechanics of a Gliding Microbe, Revealed
MAY 30, 2021
The Mechanics of a Gliding Microbe, Revealed
Humans have been able to use machines to master movement, but there are many organisms that can get around just fine on ...
Loading Comments...