Hawaii & Alaska
Collecting water samples from the subseafloor. PC: WHOI, UCSC, US NSF.

Unusual Microbes From Deep-Sea Hold Clues to Early Life

A new study has revealed how a group of deep-sea microbes provides clues to the evolution of life on Earth, according to a recent paper in The ISME Journal. Researchers from the University of Hawai‘i at Mānoa School of Ocean and Earth Science and Technology (SOEST) and others used cutting-edge molecular methods to study these microbes, which thrive in the hot, oxygen-free fluids that flow through Earth’s crust.

Called Hydrothermarchaeota, this group of microbes lives in such an extreme environment that they have never been cultivated in a laboratory for study. A research team from the Hawai‘i Institute of Marine Biology (HIMB) in SOEST, Bigelow Laboratory for Ocean Sciences in Maine and the U.S. Department of Energy Joint Genome Institute bypassed the problem of cultivation with novel genetic sequencing methods to detect and sequence individual cells or entire natural microbial communities.

They found that Hydrothermarchaeota might obtain energy by processing carbon monoxide and sulfate, which is an unexpected and previously overlooked metabolic strategy within Earth’s crust.

“Discovering this metabolic strategy in a group of microbes that is abundant in the crustal fluids of the Juan de Fuca Ridge flank provides clues about how life may be sustained deep within Earth’s crust, and also yields clues regarding the types of metabolic strategies that may occur on or within other planets,” said Michael Rappé, research professor at HIMB and one of the study’s senior authors.

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