Culture‐dependent and independent methods were used to evaluate the microbial communities in cores collected at depths up to 200 m in oil‐bearing and oil‐free strata near the Sagara oil reservoir near Shizuoka, Japan. Direct microbial counts revealed much higher numbers (2.2 × 10 4 −7.9 × 10 6 /g) of microbes in the oil‐bearing strata than in the oil‐free zones, where counts were uniform at approximately 1.0 × 10 4 /g. Molecul...

Summary Within a phylum Crenarchaeota , only some members of the hyperthermophilic class Thermoprotei , have been cultivated and characterized. In this study, we have constructed a metagenomic library from a microbial mat formation in a subsurface hot water stream of the Hishikari gold mine, Japan, and sequenced genome fragments of two different phylogroups of uncultivated thermophilic Crenarchaeota : (i) hot water crenarchaeo...