Acidilobus

A Microbial Biorealm entry on the genus Acidilobus

NCBI: Taxonomy

File:Acidilobus.png

Electron micrographs of Acidilobus aceticus. Image from Prokofeva, M. I., et al. "Acidilobus aceticus gen. nov., sp. nov., a novel anaerobic thermoacidophilic archaeon from continental hot vents in Kamchatka." Int'l J. of Sys. and Evol. Microbiol. (2000) Volume 50, p. 2003.

Classification

Higher order taxa

Archaea; Crenarchaeota; Thermoprotei; Desulfurococcales; Desulfurococcaceae

Species

Acidilobus aceticus

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.

Genome structure

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.

Ecology

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.

References

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.