In the hot springs of Yellowstone National Park, a team of researchers partially funded by the National Science Foundation (NSF) discovered a new bacterium that transforms light into chemical energy. The discovery of the chlorophyll-producing bacterium, Candidatus chloracidobacterium (Cab.) thermophilum, is described in the July 27, 2007, issue of Science in a paper led by Don Bryant of Penn State University and David M. Ward of Montana State University.
Yellowstone National Park is a tourist's wonderland because of its wildlife, mountains, geysers and hot springs. But the park is also a scientific reservoir that harbors what may be the world's largest diversity of thermophilic (heat-loving) microorganisms.
Discovered in microbial mats in three of Yellowstone's hot springs, Cab. thermophilum belongs to a new genus and species. It also belongs to the Acidobacteria phylum, a poorly characterized phylum that was not previously known to include bacteria capable of photosynthesis.
"Cab. thermophilum is the first photosynthesizing bacterium discovered in the Acidobacteria phylum," said Ronald Weiner, program director in NSF's Division of Molecular and Cellular Biosciences.
Chlorophyll-producing bacteria are so abundant that they perform half the photosynthesis on Earth. But only five of the 25 major groups, or phyla, of bacteria previously were known to contain members with this ability.
"The microbial mats give the hot springs in Yellowstone their remarkable yellow, orange, red, brown and green colors," says Bryant. Microbiologists are intrigued by Yellowstone's hot springs "because their unusual habitats house a diversity of microorganisms, but many are difficult or impossible to grow in the lab. Metagenomics has given us a powerful new tool for finding these hidden organisms and exploring their physiology, metabolism, and ecology."