New Possibilities for Undiscovered Life in Oceans Across the Solar System

UNITED STATES- In the dark and unfamiliar world that resides on the ocean floor, underwater fissures called hydrothermal vents exist to accommodate complex communities of life. These vents expel scorching hot fluids into frigid seawater, creating the chemical forces necessary for small organisms to thrive in this extreme environment. 

 

Biogeoscientists Jeffrey Dick and Everett Shock have determined that specific hydrothermal seafloor environments provide a unique habitat where certain organisms can flourish. 

This was determined in an Oct. 30, study titled, The Release of Energy During Protein Synthesis at Ultramafic-Hosted Submarine Hydrothermal Ecosystems, published in the Journal of Geophysical Research Biogeosciences by Dick and Shock; in so doing, they opened up new possibilities for life in the dark at the bottom of oceans on Earth and throughout the solar system.

 

 “To grow and reproduce, organisms must synthesize biomass,” explained Dick and Shock in the journal. “In oxygenated conditions near Earth’s surface, this is an energy-consuming process. Vastly different conditions prevail at submarine hydrothermal vents, where the mixing of oxygenated seawater with reduced fluids provides chemical disequilibria that sustain thermophilic microbial communities. Thermodynamic calculations for each protein in the genome of a model archaeal organism demonstrate the release of energy for protein synthesis from inorganic precursors over a wide temperature range in the mixing zone for fluids from an ultramafic vent but not a basalt-hosted one. These considerations point to particular submarine hydrothermal systems as hot spots of microbial proliferation for the fundamental reason that biomass synthesis is inherently favored, which is the opposite of the more familiar energetic situation in surface environments.”

 

On land, when organisms get energy out of the food they eat, they do so through cellular respiration, a process where there is an intake of oxygen and the release of carbon dioxide. However, for organisms living on the seafloor, the conditions for life are dramatically different.

“In other words, where there is life, there is water, but water needs to be driven out of the system for polymerization to become favorable,” said lead author Dick.

The discovery of life among these hydrothermal vents provides a new perspective for biochemistry and ecology. These new findings suggest that specific groups of organisms are inherently more favored in certain hydrothermal environments.

“As we explore, we’re reminded time and again that we should never equate where we live as what is habitable to life,” Shock said.