Scientists Waited Two and a Half Years to See whether Bacteria Can Eat Rock

https://blogs.scientificamerican.com/artful-amoeba/scientists-waited-two-and-a-half-years-to-see-whether-bacteria-can-eat-rock/?utm_source=Nature+Briefing&utm_campaign=a015790705-briefing-dy-20200504&utm_medium=email&utm_term=0_c9dfd39373-a015790705-44992633

Lengthy experiment reveals origins of dirt A two-and-a-half-year experiment has found evidence that bacteria make dirt. Scientists have long believed that microorganisms are involved in turning rock into soil — the mix of solid, gaseous and liquid matter, part mineral and part organic, that supports most land ecosystems. But the process tends to happen too slowly to be observed in a lab. Researchers started with an exceptionally fast-weathering rock called quartz diorite and ground it to speed things up even more. After 30 months, samples that had been kept sterile retained sharp, smooth edges, whereas those that had been exposed to bacteria looked ragged and pitted. They also contained abundant ATP, a chemical generated by feasting microbes. Scientific American blog | 5 min readReference: PNAS paper