title: Community size and metabolic rates of psychrophilic sulfate-reducing bacteria in Arctic marine sediments.
abstract: The numbers of sulfate reducers in two Arctic sediments with in situ temperatures of 2.6 and -1.7 degrees C were determined. Most-probable-number counts were higher at 10 degrees C than at 20 degrees C, indicating the predominance of a psychrophilic community. Mean specific sulfate reduction rates of 19 isolated psychrophiles were compared to corresponding rates of 9 marine, mesophilic sulfate-reducing bacteria. The results indicate that, as a physiological adaptation to the permanently cold Arctic environment, psychrophilic sulfate reducers have considerably higher specific metabolic rates than their mesophilic counterparts at similarly low temperatures.
authors.affiliation: Departments of Biogeochemistry, Max Planck Institute for Marine Microbiology, D-28359 Bremen, Germany. cknoblau@mpi-bremen.de
authors.forename: C
authors.initials: C
authors.lastname: Knoblauch
authors.forename: B B
authors.initials: BB
authors.lastname: Jørgensen
authors.forename: J
authors.initials: J
authors.lastname: Harder
mesh_terms: D001110:Arctic Regions; D003080:Cold Temperature; D015169:Colony Count, Microbial; D017753:Ecosystem; D019015:Geologic Sediments / Q000382:microbiology*; D012623:Seawater / Q000382:microbiology*; D013431:Sulfates / Q000378:metabolism*; D016999:Sulfur-Reducing Bacteria / Q000378:metabolism* / Q000502:physiology; D014871:Water Microbiology
chemical_list: D013431:Sulfates