Algae play key roles in the global carbon cycle, helping sequester significant amounts of carbon. Some algal species can bloom, or become so numerous, that they discolor coastal waters and reduce the amount of light and oxygen available in the ecosystem. Previously known as "red tide," the term "harmful algal blooms" (HABs) was introduced two decades ago to note accumulation of algal biomass can sometimes also turn the ocean waters brown or green and disrupt an ecosystem, or that red-colored waters can sometimes be harmless.
Published online the week of February 21 in the Proceedings of the National Academy of Sciences, a team of researchers including U. S. Department of Energy (DOE) Joint Genome Institute (JGI) scientists led by Igor Grigoriev, reported the first complete and annotated genome sequence of a HAB species: Aureococcus anophagefferens.
At first glance the marine phytoplankton, so tiny that 50 of them side by side span the width of a single human hair, seems innocuous. "It's a photosynthetic organism that plays a big role in carbon cycling, particularly in coastal ecosystems, and can degrade organic carbon," noted first author Christopher Gobler of Stony Brook University. "When one of these blooms occurs and you get a billion cells per liter, it represents milligrams of carbon per liter, which is much higher than you typically see in coastal ecosystems." By sequencing its genome, or biological source code, scientists can examine its "parts list" for clues to Aureococcus' ability to capture CO2, survive in varying marine environments, exploit selenium in its proteins, and outgrow many of its competitors.
The 56-million base pair genome of Aureococcus was sequenced by the DOE JGI from a culture isolated sample collected from the shores of Long Island, NY, one of the areas most affected by the microalga when it first appeared 25 years ago on the east coast of the United States.
|Contact: David Gilbert|
DOE/Joint Genome Institute