Aquatic Sciences Meeting, Albuquerque 2001

SS14 Microbial Diversity (Disciplinary Connections)

Date: Monday, February 12, 2001, Time: 10:45:00 AM

Location: Brazos

Moran, M, A, University of Georgia, Athens, GA, USA, mmoran@arches.uga.edu

González, J, M, University of Georgia, Athens, GA, USA, gonzalez@arches.uga.edu

Kiene, R, P, University of South Alabama, Mobile, AL, USA, rkiene@disl.org

Simó, R, , Institut de Ciencias del Mar, Barcelona, Spain, rsimo@icm.csic.es

Pedrós-Alió, C, , Institut de Ciencias del Mar, Barcelona, Spain, cpedros@icm.csic.es

ORGANIC SULFUR CYCLING BY THE MARINE ROSEOBACTER LINEAGE

Although most major lineages of marine bacteria identified by 16S rDNA cloning methods have no close relatives in culture, members of the Roseobacter group can be readily isolated from seawater and maintained in the laboratory. Studies of cultured Roseobacter strains indicate a widespread ability to metabolize dimethylsulfoniopropionate (DMSP) and other organic and inorganic sulfur compounds typically found in marine environments. Some cultured Roseobacters have the ability to incorporate the reduced sulfur in DMSP into cellular protein, a novel pathway for sulfur acquisition only recently discovered in natural marine bacterioplankton communities. When Roseobacter 16S rDNA sequences were quantified in the bacterial community associated with a DMSP-rich algal bloom by three molecular approaches (16S rDNA clone libraries, T-RFLP analysis, and group-specific oligonucleotide hybridization), they were found to be positively correlated with chlorophyll a, DMSP, and total dimethylated organic sulfur concentrations. The group accounted for up to 50% of the bacterial community in some surface samples from the bloom. Numerous lines of evidence suggest that the Roseobacter lineage plays a key role in organic sulfur cycling in the sea.

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Aquatic Sciences Meeting, Albuquerque 2001

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