Episode #29, The Microbes that Lurk Miles Beneath

Get In My Garden Podcast

Here on earth, the soil food web is of great interest for farmers and gardeners, and so much research has happened over the last several decades to better understand microbes and their subterainean ecosystems. In fact, the underground biosphere is basically twice as big as Earth’s oceans and contains some 23 billion tons of organisms. The Deep Carbon Observatory calls it the subterranean Galapagos. The DCO is a collaboration of around 1,000 scientists studying “deep Earth” ecosystems. According to researchers, knowing how organisms survive in the extreme conditions below Earth’s surface will help us understand the origins and evolution of life on our planet—and perhaps our closest neighbor Mars. Deep earth microbes that can live miles beneath land and seafloor habitats are called intraterrestrials, and about 70% of all the bacteria and archaea on Earth live in this subsurface environment. We know very little about them because they are so hard to access. The deep carbon observatory has sampled hundreds of deep Earth habitats, sometimes drilling boreholes three miles deep to reach them and also investigating existing mines. Millions of microbe species are estimated to occupy this biosphere, and some are able to survive boiling temperatures or pressures 400 times those at sea level.