New type of bacteria that harvests light into energy discovered

Penn State University researchers have discovered a new type of bacteria with light-harvesting antennae, which are capable of transforming light into chemical energy.

Washington, July 27 : Penn State University researchers have discovered a new type of bacteria with light-harvesting antennae, which are capable of transforming light into chemical energy.

Called photosynthesis, this process is usually attributed to green plants and their chlorophyll.

The bacteria, Candidatus Chloracidobacterium (Cab.) thermophilum, belong to the Acidobacteria phylum, which until now was not known to include any chlorophyll-producers. Researchers say this addition means that six of 25 bacteria phyla now contain light-harvesting members.

"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 lead study author Don Bryant of Penn State University.

Bryant and his colleagues spotted the bacteria in three hot springs in Yellowstone National Park-Mushroom Spring, Octopus Spring and Green Finger Pool-which are located not far from the Old Faithful Geyser.

Along with fellow light-harvesting microbes called cyanobacteria, these dwell near the surface of bacterial mats, where light and oxygen are plentiful. Temperatures there soar from 122 to 151 degrees Fahrenheit (50 to 66 degrees Celsius).

The scientists sequenced DNA from the cells of the bacteria, focusing on two genes, one a crucial component of the protein-making machinery and the other, a gene essential for converting light energy into chemical energy.

The scientists found that the bacteria sported light-harvesting antennae called chlorosomes, which each contained about 250,000 pigments. The bacterium made two types of chlorophyll, the scientists said.

"The closest relatives of Cab. thermophilum are found around Mammoth Hot Springs in Yellowstone and hot springs in Tibet and Thailand. As we look more closely, we may find relatives of Cab. thermophilum in the microbial mats of thermal sites worldwide," said Bryant.

The findings appear in the July 27 issue of the journal Science, reports Livescience.

ANI