Athens, Ga. – Last year, a team of researchers from the University of Georgia led by marine microbial ecologist Mary Ann Moran discovered a bacterial “switch gene” in two groups of plankton that helps determine whether marine bacterioplankton form sulfur compounds that rise into the atmosphere and affect the earth’s temperature or remain climatically inactive in the seas.
That new gene offers a powerful tool to study the question of how bacterioplankton are involved with ocean-atmosphere sulfur exchange and gives scientists better ways to understand how plankton are involved with everything from the health of the water to global warming.
Now, the National Science Foundation has awarded a new grant of $864,782 to a team lead by Moran, UGA microbiologist Barny Whitman, and Ronald Kiene, a professor in the department of marine sciences at the University of South Alabama, to extend the work reported last year.
“The project is important because it will help us understand how bacteria mediate a crucial regulatory point in the Earth’s sulfur cycle,” said Moran. “If bacteria degrade organic sulfur compounds to DMS [dimethyl sulfide], this ‘anti-greenhouse’ gas can be released from the ocean to the atmosphere, where it encourages cloud formation and decreases solar penetration to the Earth’s surface. We need to understand why bacteria choose this pathway over alternate routes for degradation, since it has such important implications for global temperature regulation.”
Also, the new project will use environmental functional genomics methods to get at this question, an approach in which gene expression patterns are used to address ecological questions.
“We will study gene expression in complex marine bacterial communities consisting of thousands of species that have never been cultured,” said Moran.
The broad impacts of these processes are dramatic. Marine bacterioplankton play a key role in regulating sulfur in the atmosphere, a process of great importance for global climate regulation and marine productivity.
In addition to the researchers’ work, graduate and undergraduate students and two post-doctoral associates will be trained during the course of the grant, and high school biology students in Athens will learn first-hand about marine microbiology. This will include research in bacterial diversity and discovery studies on the Georgia coast, follow-up training in molecular tools and bioinformatics in their own classroom, and summer internships at UGA and at the Dauphin Island Sea Lab, located on a barrier island in Mobile Bay.
