Flightless birds, blind cave shrimp, and other oddities suggest a "use it or lose it" tendency in evolution. In the microbial world, an unusual marine microorganism appears to have ditched several major metabolic pathways, leaving it with a remarkably reduced set of genes.
This metabolic minimalist is a specialist uniquely suited to performing one very important function: taking nitrogen gas from the atmosphere and "fixing" it into a form that makes this essential nutrient available to other organisms. Nitrogen fixation fertilizes the oceans, controlling overall biological productivity and thereby affecting how much carbon dioxide the oceans absorb from the atmosphere.
Jonathan Zehr, the marine microbiologist who discovered the microbe, said it has stubbornly resisted efforts to grow it in the laboratory. But that hasn't stopped his team from determining the complete DNA sequence of its genome. Genome analysis enabled the researchers to reconstruct the organism's unusual metabolic lifestyle. They published their findings in Nature in a paper available online February 21.
This metabolic minimalist is a specialist uniquely suited to performing one very important function: taking nitrogen gas from the atmosphere and "fixing" it into a form that makes this essential nutrient available to other organisms. Nitrogen fixation fertilizes the oceans, controlling overall biological productivity and thereby affecting how much carbon dioxide the oceans absorb from the atmosphere.
Jonathan Zehr, the marine microbiologist who discovered the microbe, said it has stubbornly resisted efforts to grow it in the laboratory. But that hasn't stopped his team from determining the complete DNA sequence of its genome. Genome analysis enabled the researchers to reconstruct the organism's unusual metabolic lifestyle. They published their findings in Nature in a paper available online February 21.
