Geoglobus

Abstract

Ge.o.glo'bus. Gr. n. Ge the Earth; L. masc. n globus ball; N.L. masc. n. Geoglobus a ball from the Earth. Euryarchaeota / Archaeoglobi / Archaeoglobales / Archaeoglobaceae The genus Geoglobus is a member of the Domain Archaea , Phylum Euryarchaeota , Class Archaeoglobi , Order Archaeoglobales , and family Archaeoglobaceae . Two species have been isolated from this genus; Geoglobus ahangari and Geoglobus acetivorans . The type strain is G. ahangari strain 234 T . Both species were isolated from hydrothermal vent systems and are strict hyperthermophilic anaerobes that can grow heterotrophically or autotrophically by coupling the oxidation of organic compounds or molecular hydrogen with iron reduction. Their cells are nonsporulating cocci, 0.3–0.5 µm in diameter, usually arranged as single cells or in pairs, and rely on archaella for locomotion and numerous extracellular pili‐like structures for attachment. The pH, temperature, and salinity optima for G. ahangari and G. acetivorans are 7.0 and 6.8, 88 and 81 °C, and 1.9% and 2.5%, respectively. The mol% G + C content of the genomes of G. ahangari and G. acetivorans is 53.1 and 46.8. The closest phylogenetic relative outside of their genus is Archaeoglobus fulgidus and their 16S rRNA gene sequences are 97% identical to each other. The mol% G + C of the DNA is : 46.8–53.1. Type species : Geoglobus ahangari .