Comparative studies of four types of cyanobacteria "photosynthetic" microbes that derive energy from sunlight, just like plants were published today on the websites of the journals Nature and Proceedings of the National Academy of Sciences (PNAS). Three of the microbes two strains of Prochlorococcus and one of Synechococcus were among the first organisms to have their DNA sequenced at JGI in the late 1990s, and are the first ocean bacteria to be sequenced.

Cyanobacteria are important in part because of their ability to turn sunlight and carbon into organic material. As the smallest yet most abundant photosynthetic organisms in the oceans, cyanobacteria play a critical role in regulating atmospheric carbon dioxide, a chief contributor to global climate change. Scientists estimate that Prochlorococcus and Synechococcus remove about 10 billion tons of carbon from the air each year as much as two-thirds of the total carbon fixation that occurs in the oceans.

Patrick Chain, a biologist at Lawrence Livermore National Laboratory (LLNL) and co-author of the two Nature papers, said the three cyanobacteria sequenced by JGI were "hand-picked" to help scientists "begin to understand the physiological and genetic controls of photosynthesis, nitrogen fixation and carbon cycling." The sequencing was funded by the DOE Office of Science's Office of Biological and Environmental Research as part of its mission to study climate change and carbon management.

"While many questions remain," said Dr. Raymond L. Orbach, director of DOE's Office of Science, "it's clear that Prochlorococcus and Synechococcus play an immensely significant role in photosynthetic ocean carbon sequestration. Having the completed
'"/>

Contact: Charles Osolin
osolin1@llnl.gov
925-296-5643
DOE/Joint Genome Institute
13-Aug-2003