Open AccessDistribution of candidate division JS1 and other Bacteria in tidal sediments of the German Wadden Sea using targeted 16S rRNA gene PCR‐DGGE
Author(s) -
Webster Gordon,
Yarram Laura,
Freese Elke,
Köster Jürgen,
Sass Henrik,
Parkes R. John,
Weightman Andrew J.
Publication year - 2007
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2007.00372.x
Subject(s) - temperature gradient gel electrophoresis , biology , chloroflexi (class) , sediment , 16s ribosomal rna , microbial population biology , gammaproteobacteria , ecology , environmental chemistry , bacteria , actinobacteria , paleontology , chemistry
The bacterial candidate division JS1 dominates a number of 16S rRNA gene libraries from deep subseafloor sediments, yet its distribution in shallow, subsurface sediments has still to be fully documented. Sediment cores (down to 5.5 m) from Wadden Sea tidal flats (Neuharlingersieler Nacken and Gröninger Plate) were screened for JS1 16S rRNA genes using targeted PCR‐denaturing gradient gel electrophoresis (DGGE), which also detects some other important Bacteria . Bacterial subpopulations at both sites were dominated by Gammaproteobacteria in the upper sediment layers (down to 2 m) and in deeper layers by members of the Chloroflexi . The deeper layers of Neuharlingersieler Nacken consisted of grey mud with low sulphate (0.1–10 mM), elevated total organic carbon (TOC) (∼1–2%) and JS1 sequences were abundant. In contrast, the deeper sandy layers of Gröninger Plate, despite also having reduced sulphate concentrations, had lower TOC (<0.6%) with few detectable JS1 sequences. Results indicated that JS1 prefers muddy, shallow, subsurface sediments with reduced sulphate, whereas Chloroflexi may out‐compete JS1 in shallow, sandy, subsurface sediments. Bacterial population changes at both sites (∼2 m) were confirmed by cluster analysis of DGGE profiles, which correlated with increased recalcitrance of the organic matter. This study extends the biogeographical range of JS1. The presence of JS1 and Chloroflexi in Wadden Sea sediments demonstrates that subsurface tidal flats contain similar prokaryotic populations to those found in the deeper subseafloor biosphere.