Higher order taxa
Archaea; Crenarchaeota; Thermoprotei; Desulfurococcales; Desulfurococcaceae
Description and significance
Acidilobus (acid lobe) is an obligately anaerobic, hyperthermophilic, acidophilic archaeon that grows in the temperatures between 60-92°C (optimum = 85°C) and in the pH range of 2.0-6.0 (optimum at 3.8). It forms smooth white colonies which are approximately 1 mm in diameter.
There are currently no genome project held for this archaeon. The G+C content of its DNA, however, is found to be 53.8%.
Cell structure and metabolism
The cells of Acidilobus are regular or irregular cocci with diameter of 1-2 µm. They are non-motile and have a cell envelope consisting of one S-layer attached to the cytoplasmic membrane. The S-layer composes of a single layer of subunits covered with a thin osmophilic layer that may be naturally proteinaceous.
It ferments starch and forms acetate as the main growth product (other growth substrates are yeast extract, beef extract and soya extract). Elemental sulfur stimulates growth on yeast, soya, and beef extracts and is reduced to H2S. The organism is unable to utilize acetate, arabinose, cellulose, formate, fructose, galactose, glucose, glycine, guar gum, lichenan, malate, maltose, methanol, pectin, pyruvate, propionate, xylan, xylose, and mixture of amino acids.
The strains of Acidilobus aceticus were isolated from the acidic hot springs of the Moutnovski volcano in Kamchatka, Russia. Similar to most other thermoacidophilic isolates, the habitat of the archaeon is terrestrial acidic hot springs.
Prokofeva, M. I., Miroshnichenko, M. L., Kostrikina, N. A., Chernyh, N. A., Kuznetsov, B. B., Tourova, T. P., and Bonch-Osmolovskaya. "Acidilobus aceticus gen. nov., sp. nov., a novel anaerobic thermoacidophilic archaeon from continental hot vents in Kamchatka." International Journal of Systematic and Evolutionary Microbiology (2000) Volume 50, p. 2001-2008.