Pac-Man, the open-mouthed face of the most successful arcade game ever, is much more well-known than any of the one-celled organisms called protists, at least among people over 30. But the first study to characterize protists in soils from around the world — co-authored by Smithsonian scientists — found that the most common groups of soil protists behave exactly like Pac-Man: moving through the soil matrix, gobbling up bacteria. Their results are published in Science Advances .
“As part of a bigger project to understand all of the microbes in soil we are characterizing bacteria and fungi, but also a lesser-known, but equally important group called protists, “said Angela Oliverio, former STRI intern and lead author on the paper with professor Noah Fierer and post-doctoral fellow Manuel Delgado-Baquerizo at the University of Colorado , Boulder; staff scientist Ben Turner at the Smithsonian Tropical Research Institute in Panama; researcher Stefan Geisen at the Netherlands Institute of Ecology and professor Fernando Maestre at the Universidad Rey Juan Carlos and the Universidad de Alicante, Spain.
Protists reproduce quickly and are likely much more responsive to climate change than larger forms of life. Like the cartoon character Sheldon Plankton in Spongebob Squarepants, protists are not plants, animals or fungi. They are single-celled organisms but, unlike bacteria, they have a nucleus. They move through water using whip-like flagellae and tiny hairs called cilia. Some of the nastier protists cause sleeping sickness, malaria and red tide, but nearly all play important, if mysterious, roles in the energy- and nutrient-trading relationships that connect ecosystems.