Scientists classify organisms under one of three categories: eukaryotes, which include plants, animals and fungi, bacteria and archaea. Some researchers think archaea may be descended from some of the earlier life forms on the plant, and that they haven’t changed very much over time. By studying them, researchers hope to learn more about the origins of life. Archaea may represent as much as 20 percent of the Earth’s total biomass but are tiny organisms approximately 1 micron in size. To get an idea of just how small that is, consider that there are over 25,000 microns in an inch.
Photo: W.B. Hamilton
Archaea can tolerate extreme temperatures and acidity and can be found in very hot, very cold or very salty environments such as acidic hot springs or salt lakes. Because they are used to extreme environments — some species consider oxygen a toxin and need to be grown in airtight environments if removed for study — they are difficult to cultivate and study in the laboratory. Despite these challenges, archaeal studies have produced a number of commercial applications: some laundry detergents make use heat resistant enzymes first found in archaeal species, for example. Archaeal species also produce hydrogen, methane and ethanol, which make them interesting from a bioenergy perspective. Researchers also hope to learn how archaea could be used to clean contaminated sites.
Principal Investigators: Todd Lowe (University of California, Santa Cruz)
Program: CSP 2009