Distribution of Complex and Core Lipids within New Hyperthermophilic Members of the Archaea Domain

Core and complex lipids of several new hyperthermophilic archaeal isolates were analyzed. The organisms belong to the Sulfolobales,Archaeoglobus, Pyrobaculum, and Methanococcus. A detailed structural investigation of complex lipids of Pyrobaculum species is reported. The different lipid structures are of help for a rapid and simple phylogenetic classification of the new isolates. They are in agreement with the classification based on other features

Sulfolobus metallicus, sp. nov., a Novel Strictly Chemolithoautotrophic Thermophilic Archaeal Species of Metal-Mobilizers

Five new isolates of archaeal coccoid thermoacidophiles were obtained from Icelandic solfataric fields. They are strict chemolithoautotrophs gaining energy by oxidation of S° and sulfidic ores. The new strains grow between 50 and 75 °C and p H 1 and 4.5 and tolerate N a C l concentrations of up to 3.0%. The G C - content of their D N A is 38 m o l % . The new isolates resemble members of Sulfolobus in their morphology, their ability to oxidize reduced sulfur compounds and their GC-content. They are different in their strictly chemolithoautotrophic mode of life, their ore-leaching capacity, D N A / D N A hybridization and incomplete serological cross-reaction of R N A polymerase. Therefore, we describe here a new species, Sulfolobus metallicus. Type strain is Sulfolobus metallicus (Kra 2 3 ; D S M 6482)

Growth by Aerobic Oxidation of Molecular Hydrogen in Archaea - a Metabolic Property so far Unknown for this Domain

Members of the genera Sulfolobus, Acidianus and Metallosphaera were found to be able to grow chemo-lithoautotrophically on H 2 / 0 2. Under these conditions, the strains grew between about 0.2 and 10 % 0 2 per vol. (opt: —1 % 0 2). The oxidation of H 2 by 0 2 was confirmed by the addition of D 2 as a tracer. To our knowledge, this is the first demonstration of H 2 oxidation by 0 2 among the Archaea