Light drives photosynthesis, the mechanism used by many microbes to create energy from the Sun. But what if you live beneath a glacier where light is scarce? Microbes in such environments create energy by interacting with and breaking down local bedrock.
While it’s known how the microbes affect the rock, a new study in Geology from astrobiologists at Montana State University show how the rock affects the microbes. They’ve identified pyrite as a key mineral in determining microbial community structure and composition. Given how common pyrite is, it may be the dominant control on microbial communities in many subglacial systems. Mineral-based energy may therefore play a fundamental role in sustaining subglacial microbial populations and enabling their persistence over glacial time scales.