Active nitrogen-fixing heterotrophic bacteria at and below the chemocline of the central Baltic Sea. 2013

Hanna Farnelid, and Mikkel Bentzon-Tilia, and Anders F Andersson, and Stefan Bertilsson, and Günter Jost, and Matthias Labrenz, and Klaus Jürgens, and Lasse Riemann
Department of Natural Sciences, Linnaeus University, Kalmar, Sweden.

The Baltic Sea receives large nitrogen inputs by diazotrophic (N2-fixing) heterocystous cyanobacteria but the significance of heterotrophic N2 fixation has not been studied. Here, the diversity, abundance and transcription of the nifH fragment of the nitrogenase enzyme in two basins of the Baltic Sea proper was examined. N2 fixation was measured at the surface (5 m) and in anoxic water (200 m). Vertical sampling profiles of >10 and <10 μm size fractions were collected in 2007, 2008 and 2011 at the Gotland Deep and in 2011 in the Bornholm Basin. Both of these stations are characterized by permanently anoxic bottom water. The 454-pyrosequencing nifH analysis revealed a diverse assemblage of nifH genes related to alpha-, beta- and gammaproteobacteria (nifH cluster I) and anaerobic bacteria (nifH cluster III) at and below the chemocline. Abundances of genes and transcripts of seven diazotrophic phylotypes were investigated using quantitative polymerase chain reaction revealing abundances of heterotrophic nifH phylotypes of up to 2.1 × 10(7) nifH copies l(-1). Abundant nifH transcripts (up to 3.2 × 10(4) transcripts l(-1)) within nifH cluster III and co-occurring N2 fixation (0.44±0.26 nmol l(-1) day(-1)) in deep water suggests that heterotrophic diazotrophs are fixing N2 in anoxic ammonium-rich waters. Our results reveal that N2 fixation in the Baltic Sea is not limited to illuminated N-deplete surface waters and suggest that N2 fixation could also be of importance in other suboxic regions of the world's oceans.

UI MeSH Term Description Entries
D009586 Nitrogen Fixation The process in certain BACTERIA; FUNGI; and CYANOBACTERIA converting free atmospheric NITROGEN to biologically usable forms of nitrogen, such as AMMONIA; NITRATES; and amino compounds. Diazotrophy,Diazotrophic Activity,Dinitrogen Fixation,N2 Fixation,Activities, Diazotrophic,Activity, Diazotrophic,Diazotrophic Activities,Fixation, Dinitrogen,Fixation, N2,Fixation, Nitrogen
D009792 Oceans and Seas A great expanse of continuous bodies of salt water which together cover more than 70 percent of the earth's surface. Seas may be partially or entirely enclosed by land, and are smaller than the five oceans (Atlantic, Pacific, Indian, Arctic, and Antarctic). Seas,Oceans,Seas and Oceans
D010088 Oxidoreductases The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9) Dehydrogenases,Oxidases,Oxidoreductase,Reductases,Dehydrogenase,Oxidase,Reductase
D010802 Phylogeny The relationships of groups of organisms as reflected by their genetic makeup. Community Phylogenetics,Molecular Phylogenetics,Phylogenetic Analyses,Phylogenetic Analysis,Phylogenetic Clustering,Phylogenetic Comparative Analysis,Phylogenetic Comparative Methods,Phylogenetic Distance,Phylogenetic Generalized Least Squares,Phylogenetic Groups,Phylogenetic Incongruence,Phylogenetic Inference,Phylogenetic Networks,Phylogenetic Reconstruction,Phylogenetic Relatedness,Phylogenetic Relationships,Phylogenetic Signal,Phylogenetic Structure,Phylogenetic Tree,Phylogenetic Trees,Phylogenomics,Analyse, Phylogenetic,Analysis, Phylogenetic,Analysis, Phylogenetic Comparative,Clustering, Phylogenetic,Community Phylogenetic,Comparative Analysis, Phylogenetic,Comparative Method, Phylogenetic,Distance, Phylogenetic,Group, Phylogenetic,Incongruence, Phylogenetic,Inference, Phylogenetic,Method, Phylogenetic Comparative,Molecular Phylogenetic,Network, Phylogenetic,Phylogenetic Analyse,Phylogenetic Clusterings,Phylogenetic Comparative Analyses,Phylogenetic Comparative Method,Phylogenetic Distances,Phylogenetic Group,Phylogenetic Incongruences,Phylogenetic Inferences,Phylogenetic Network,Phylogenetic Reconstructions,Phylogenetic Relatednesses,Phylogenetic Relationship,Phylogenetic Signals,Phylogenetic Structures,Phylogenetic, Community,Phylogenetic, Molecular,Phylogenies,Phylogenomic,Reconstruction, Phylogenetic,Relatedness, Phylogenetic,Relationship, Phylogenetic,Signal, Phylogenetic,Structure, Phylogenetic,Tree, Phylogenetic
D000458 Cyanobacteria A phylum of oxygenic photosynthetic bacteria comprised of unicellular to multicellular bacteria possessing CHLOROPHYLL a and carrying out oxygenic PHOTOSYNTHESIS. Cyanobacteria are the only known organisms capable of fixing both CARBON DIOXIDE (in the presence of light) and NITROGEN. Cell morphology can include nitrogen-fixing heterocysts and/or resting cells called akinetes. Formerly called blue-green algae, cyanobacteria were traditionally treated as ALGAE. Algae, Blue-Green,Blue-Green Bacteria,Cyanophyceae,Algae, Blue Green,Bacteria, Blue Green,Bacteria, Blue-Green,Blue Green Algae,Blue Green Bacteria,Blue-Green Algae
D001419 Bacteria One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive. Eubacteria
D012623 Seawater The salinated water of OCEANS AND SEAS that provides habitat for marine organisms. Sea Water,Sea Waters,Seawaters,Water, Sea,Waters, Sea
D044822 Biodiversity The variety of all native living organisms and their various forms and interrelationships. Biological Diversity,Diversity, Biological

Related Publications

Hanna Farnelid, and Mikkel Bentzon-Tilia, and Anders F Andersson, and Stefan Bertilsson, and Günter Jost, and Matthias Labrenz, and Klaus Jürgens, and Lasse Riemann
January 2007, Environmental microbiology,
Hanna Farnelid, and Mikkel Bentzon-Tilia, and Anders F Andersson, and Stefan Bertilsson, and Günter Jost, and Matthias Labrenz, and Klaus Jürgens, and Lasse Riemann
June 2005, Amino acids,
Hanna Farnelid, and Mikkel Bentzon-Tilia, and Anders F Andersson, and Stefan Bertilsson, and Günter Jost, and Matthias Labrenz, and Klaus Jürgens, and Lasse Riemann
August 2002, Applied and environmental microbiology,
Hanna Farnelid, and Mikkel Bentzon-Tilia, and Anders F Andersson, and Stefan Bertilsson, and Günter Jost, and Matthias Labrenz, and Klaus Jürgens, and Lasse Riemann
May 1979, Applied and environmental microbiology,
Hanna Farnelid, and Mikkel Bentzon-Tilia, and Anders F Andersson, and Stefan Bertilsson, and Günter Jost, and Matthias Labrenz, and Klaus Jürgens, and Lasse Riemann
April 1996, Applied and environmental microbiology,
Hanna Farnelid, and Mikkel Bentzon-Tilia, and Anders F Andersson, and Stefan Bertilsson, and Günter Jost, and Matthias Labrenz, and Klaus Jürgens, and Lasse Riemann
March 1995, Amino acids,
Hanna Farnelid, and Mikkel Bentzon-Tilia, and Anders F Andersson, and Stefan Bertilsson, and Günter Jost, and Matthias Labrenz, and Klaus Jürgens, and Lasse Riemann
July 2015, mBio,
Hanna Farnelid, and Mikkel Bentzon-Tilia, and Anders F Andersson, and Stefan Bertilsson, and Günter Jost, and Matthias Labrenz, and Klaus Jürgens, and Lasse Riemann
January 1982, Applied and environmental microbiology,
Hanna Farnelid, and Mikkel Bentzon-Tilia, and Anders F Andersson, and Stefan Bertilsson, and Günter Jost, and Matthias Labrenz, and Klaus Jürgens, and Lasse Riemann
October 2002, Applied and environmental microbiology,
Hanna Farnelid, and Mikkel Bentzon-Tilia, and Anders F Andersson, and Stefan Bertilsson, and Günter Jost, and Matthias Labrenz, and Klaus Jürgens, and Lasse Riemann
April 2007, Ambio,
Copied contents to your clipboard!