Query: NC_006177:280234 Symbiobacterium thermophilum IAM 14863, complete genome
Lineage: Symbiobacterium thermophilum; Symbiobacterium; Shewanellaceae; Clostridiales; Firmicutes; Bacteria
General Information: This symbiotic and thermophilic bacterium was discovered by screening for thermostable tryptanophases in Japanese compost. Cultured growth of this organism requires the presence of another bacterial species, such as a Bacillus or Escherichia coli, which provides diffusable metabolites required for its growth. Pure cultures can be obtained by growing Symbiobacterium thermophilum in a bioreactor, separated from its symbiotic counterpart by a dialysis membrane. Because of its symbiotic nature, it cannot be cultured with conventional methods. Despite a negative reaction for gram stain, this species is placed with the gram-positive bacteria based on 16s phylogenetic analysis.
Subject: NC_000917:1778173 Archaeoglobus fulgidus DSM 4304, complete genome
Lineage: Archaeoglobus fulgidus; Archaeoglobus; Archaeoglobaceae; Archaeoglobales; Euryarchaeota; Archaea
General Information: This is the type strain (DSM 4304) of the Archaeoglobales, and was isolated from a geothermally heated sea floor at Vulcano Island, Italy. Doubling time is four hours under optimal conditions. The organism is an autotrophic or organotrophic sulfate/sulfite respirer. An additional distinguishing characteristic is blue-green fluorescence at 420 nm. This bacterium is the first sulfur-metabolizing organism to have its genome sequence determined. Growth by sulfate reduction is restricted to relatively few groups of prokaryotes; all but one of these are Eubacteria, the exception being the archaeal sulfate reducers in the Archaeoglobales. These organisms are unique in that they are only distantly related to other bacterial sulfate reducers, and because they can grow at extremely high temperatures. The known Archaeoglobales are strict anaerobes, most of which are hyperthermophilic marine sulfate reducers found in hydrothermal environments. High-temperature sulfate reduction by Archaeoglobus species contributes to deep subsurface oil-well 'souring' by iron sulfide, which causes corrosion of iron and steel in oil-and gas-processing systems.