Ferroglobus placidus gen. nov., sp. nov., A novel hyperthermophilic archaeum that oxidizes Fe2+ at neutral pH under anoxic conditions.

A novel coccoid, anaerobic, Fe2+-oxidizing archaeum was isolated from a shallow submarine hydrothermal system at Vulcano, Italy. In addition to ferrous iron, H2 and sulfide served as electron donors. NO3- was used as electron acceptor.

Formation of ammonium from nitrate during chemolithoautotrophic growth of the extremely thermophilic bacterium ammonifex degensii gen. nov. sp. nov.

A novel, extremely thermophilic bacterium has been isolated from a neutral volcanic hot spring. The gram-negative, rod-shaped cells were motile and exhibited a complex cell wall composed of murein and a surface protein layer covered by a surface coat. The core lipids consisted of non-phytanyl mono- and diethers and of fatty acid esters.

Isolation of a hyperthermophilic archaeum predicted by in situ RNA analysis.

A variety of hyperthermophilic bacteria and archaea have been isolated from high-temperature environments by plating and serial dilutions. However, these techniques allow only the small percentage of organisms able to form colonies, or those that are predominant within environmental samples, to be obtained in pure culture. Recently, in situ 16S ribosomal RNA analyses of samples from the Obsidian hot pool at Yellowstone National Park, Wyoming, revealed a variety of archaeal sequences, which were all different from those of previously isolated species.