Archaeal 16S rDNA clones retrieved from paddy soil DNA were sequenced.
Among 100 clones, 88 clones were assigned to methanogens and nine clo
nes were assigned to crenarchaeota. However, three of the nine clones
were phylogenetically far from the cultured crenarchaeota and closely
related to marine planktonic archaea. The other three clones showed ex
tremely novel 16S rDNA sequences and were phylogenetically far from bo
th Crenarchaeota and Euryarchaeota. This paper reports the ubiquitous
presence of crenarchaeotal and extremely novel clones in paddy soils.