Yellowstone Times

Montana State University researchers have published a study in Nature Communications that provides new insights into how ancient microorganisms adapted from low-oxygen prehistoric environments to those of today. The research builds on over 20 years of scientific investigation in Yellowstone National Park by MSU professor Bill Inskeep.

The article, titled “Respiratory Processes of Early-evolved Hyperthermophiles in Sulfidic and Low-oxygen Geothermal Microbial Communities,” was released on January 2. Authors Inskeep, a professor in the Department of Land Resources and Environmental Sciences, and Mensur Dlakic, an associate professor in the Department of Microbiology and Cell Biology, compared heat-loving organisms found in two Yellowstone thermal features: Conch Spring and Octopus Spring.

Inskeep and Dlakic chose these locations due to their geochemical similarities, with Conch Spring having higher levels of sulfide and oxygen than Octopus Spring. This allowed them to examine two contrasting thermal environments with varying oxygen levels.

Three types of thermophilic microbes were identified in both springs, which maintain temperatures around 190 degrees Fahrenheit. The study suggests that these microbes' lifestyles can provide insights into how life evolved before and during the Great Oxidation Event about 2.4 billion years ago when Earth's atmosphere shifted from almost no oxygen to nearly 20% oxygen content.

“When oxygen started to increase in the environment, these thermophiles were likely important in the origin of microbial life,” said Inskeep. “There was an evolution of organisms that utilized oxygen.”

The microorganisms studied by Inskeep and Dlakic reside within "streamers" that live in rapid stream currents. These streamers attach to rocks within the spring and grow filaments that move with the current.

Despite visual similarities, streamers at Conch and Octopus Springs hosted different collections of microbes. While three species were common to both springs, Octopus Spring's higher oxygen levels supported greater diversity. This diversity offers insight into how these organisms evolved to thrive as atmospheric oxygen increased.

The authors examined respiratory genes found in microbes from both springs. Genes adapted to low oxygen were more active at Conch Spring, while those adapted to higher oxygen levels were expressed more at Octopus Spring as atmospheric oxygen increased during the Great Oxidation Event.

In his extensive research tenure at MSU, Inskeep has gathered substantial data from Yellowstone but believes there is still much more to discover. In 2020, he and Dlakic received a grant from the National Science Foundation’s Opportunities for Promoting Understanding through Synthesis program for their ongoing study on Yellowstone’s thermophiles.

MSU's location within the Greater Yellowstone Ecosystem makes it well-suited for this type of research, according to Inskeep. “It would be very difficult to reproduce this kind of an experiment in the laboratory," he said.

While studying hot spring-dwelling organisms may seem unrelated to human life, they enhance our understanding of how various life forms adapt for survival. “It may seem counterintuitive to understand complex life by studying something that's simple," said Dlakic.