Weird Light-harvesting Species Found in Yellowstone
Yellowstone National Park is famous for its wide variety of animals, strange rock formations, geysers and colorful hot springs. It now has a new distinction of hosting a novel heat-loving bacterium that transforms light into chemical energy. Cab. thermophilum grows near the surface where there is light and oxygen, at a temperature of about 50 to 66 degrees Celsius (122 to 151 degrees Fahrenheit).
A research team found the new bacterium living in the same hot springs as the most-famous Yellowstone microbe, Thermus aquaticus, which helped spark a revolutionary new laboratory technique known as polymerase chain reaction (PCR) with its ability to withstand high temperatures. PCR is now widely used in research laboratories and doctor's offices for recombinant DNA sequencing, genetic fingerprinting and paternity testing, among other uses.
Hot springs of Yellowstone are a scientific reservoir housing what is believed to be the world's largest diversity of thermophilic bacteria. Scientists have searched these habitats for decades hoping to find new organisms that may have important applications in biotechnology.
"Finding a previously unknown, chlorophyll-producing microbe is the discovery of a lifetime for someone who has studied bacterial photosynthesis for as long as I have (35 years)," said researcher Don Bryant. "I wouldn't have been as excited if I had reached into that mat and pulled out a gold nugget the size of my fist!"
Remarkably, the new genus and species of bacterium known as Cab. thermophilum also belongs to a new phylum, Acidobacteria. This discovery marks only the third time in the past 100 years that a new bacterial phylum has been added to the list of those with chlorophyll-producing members. Although chlorophyll-producing bacteria are so abundant that they perform half the photosynthesis on Earth, 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," explained Bryant. "Microbiologists are intrigued by Octopus and Mushroom 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."
Unexpectedly, the new bacterium has special light-harvesting antennae known as chlorosomes, which contain about 250,000 chlorophylls each. No member of this phylum, nor any aerobic microbe has ever been known to make chlorosomes before this discovery. Scientists are hopeful that this discovery may lead to novel applications in the field of biotechnology.
Posted by Rebecca Sato.
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