ARCUS | Arctic Research Consortium of the United States

6th Annual ARCUS Award for Arctic Research Excellence

Honorable Mention Life Science
Submitted by   Robin Brinkmeyer
Authors   Robin Brinkmeyer
Category   Life Science
Title   Oxidation and Utilization of Dimethylsulfide and Dibromomethane by Bacteria in Arctic Sea-ice
Affiliation   Biological Oceanography, University of Bremen, Bremerhaven, Germany

Abstract

Algal-rich sea ice collected in the Arctic Ocean during the F.S. Polarstern ARKXVI/2 expedition was incubated with 14C labeled- dimethylsulfide and dibromomethane, respectively, over several days. Oxidation of these compounds by bacteria was measurable. The same sample was enriched with unlabeled dimethylsulfide, dibromomethane and methane as the sole carbon sources. Clone sequences from these enrichment cultures revealed diverse consortia including bacteria closely related to an obligate methylotroph, Methylophaga sp. Application of MICRO-FISH indicates that only certain members of the gamma subclass of Proteobacteria incorporate dimethylsulfide as cell material.