The Geomicrobiology Group at UNLV studies the physiology of sulfate-reducing bacteria (SRB) in the context of biogeochemistry and astrobiology

Biogeochemistry – interactions between SRB and Fe-S minerals

Sulfate-reducing bacteria (SRB) are ubiquitous in anoxic sedimentary environments, where they drive the biogeochemical cycles of carbon and sulfur. They reduce sulfate and oxidize the majority of organic carbon deposited in sediments. Sulfide, the main product of sulfate reduction, interacts with metals, notably Fe, to precipitate as Fe-S minerals. SRB are not only the main source of sulfide that precipitate in Fe-S minerals, they also influence their physical properties: mineralogy, composition and morphology. In turn, minerals can influence the life of microorganisms. We study the impact of Fe-S minerals on the physiology, metabolic activity and longevity of SRB.

Astrobiology – can SRB live on Europa?

The next frontier for the search of life is on Ocean Worlds of the outer solar system. In a NASA-funded project, we explore the pressure limits for microbial life in conditions simulating those on Europa, the icy moon of Jupiter. We also evaluate the formation of biosignatures produced by SRB in the deep ocean of Europa to inform search of microbial life in upcoming missions.