<I>nirS</I>-containing denitrifier communities in the water column and sediment of the Baltic Sea
The aim of this study was to compare structural differences in the <I>nirS</I>-type denitrifying microbial communities along the environmental gradients observed in the water column and coastal sediments of the Baltic Sea. To link community structure and environmental gradients, denitrif...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2007-05-01
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| Series: | Biogeosciences |
| Online Access: | http://www.biogeosciences.net/4/255/2007/bg-4-255-2007.pdf |
| Summary: | The aim of this study was to compare structural differences in the
<I>nirS</I>-type denitrifying microbial communities along the environmental gradients
observed in the water column and coastal sediments of the Baltic Sea. To
link community structure and environmental gradients, denitrifier
communities were analyzed by terminal restriction fragment length
polymorphism (T-RFLP) based on <I>nirS</I> as a functional marker gene for
denitrification. <I>nirS</I>-type denitrifier community composition was further evaluated
by phylogenetic analysis of <I>nirS</I> sequences from clone libraries. T-RFLP analysis
indicated some overlap but also major differences between communities from
the water column and the sediment. Shifts in community composition along the
biogeochemical gradients were observed only in the water column while
denitrifier communities were rather uniform within the upper 30 mm of the
sediment. Specific terminal restriction fragments (T-RFs) indicative of the
sulfidic zone suggest the presence of nitrate-reducing and sulfide-oxidizing
microorganisms that were previously shown to be important at the
suboxic-sulfidic interface in the water column of the Baltic Sea.
Phylogenetic analysis of <I>nirS</I> genes from the Baltic Sea and of sequences from
marine habitats all over the world indicated distinct denitrifier
communities that grouped mostly according to their habitats. We suggest that
these subgroups of denitrifiers had developed after selection through
several factors, i.e. their habitats (water column or sediment), impact by
prevalent environmental conditions and isolation by large geographic
distances between habitats. |
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| ISSN: | 1726-4170 1726-4189 |