Normal 0 false false false MicrosoftInternetExplorer4 Some bacteria from MonoLake in California do photosynthesis the old-fashioned way — really old-fashioned: They use arsenic instead of oxygen.
Arsenic photosynthesis may be an ancient form of metabolism, dating from the earliest days of life on Earth before oxygen filled the atmosphere, says Ronald Oremland, a microbiologist and geochemist with the United States Geological Survey in Menlo Park, Calif. Oremland and his colleagues describe the two types of newly discovered bacteria in the Aug. 15 Science.