Quantitative oligonucleotide hybridization experiments indicated that the relative abundance of archaeal 16S r RNA in deep-sea sediments (1500 m deep) ranged from about 2.5 to 8% of the total prokaryotic r RNA.
Clone libraries of PCR-amplified archaeal r RNA genes (r DNA) were constructed from 10 depth intervals obtained from sediment cores collected at depths of 1,500, 2,600, and 4,500 m.
Phylogenetic analyses of archaeal r DNA sequences were used in combination with r RNA-targeted probe hybridization to nucleic acid extracts and denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified r DNA fragments.
We report here a high diversity of novel crenarchaeal and euryarchaeal phylotypes associated with deep-sea sediments, whose relative abundance ranged from about 2.5 to 8% of the total prokaryotic r RNA.
Detailed studies on the distribution of the planktonic in oxic and anoxic marine sediments and in the water column has been obtained by using either lipids as biological markers for the detection of these microorganisms (11, 25, 27).