Query: NC_015474:644552 Pyrococcus sp. NA2 chromosome, complete genome
Lineage: Pyrococcus; Pyrococcus; Thermococcaceae; Thermococcales; Euryarchaeota; Archaea
General Information: Pyrococcus has similar characteristics of other thermoautotrophican archaea such as Archaeoglobus, and Methanococcus in the respect that they are all thermophilic and anaerobic. Pyrococcus differs, however, because its optimal growth temperature is nearly 100 °C and dwells at a greater sea depth than the other archaea. Studying Pyrococcus helps give insight to possible mechanisms used to endure extreme environmental conditions like high temperatures and high pressure.
Subject: NC_018870:1417851 Thermacetogenium phaeum DSM 12270 chromosome, complete genome
Lineage: Thermacetogenium phaeum; Thermacetogenium; Thermoanaerobacteraceae; Thermoanaerobacterales; Firmicutes; Bacteria
General Information: Nitrogen fixation. Thermophilic strictly anaerobic bacterium oxidizing acetate to CO2 in syntrophic association with a methanogenic partner. Capable of growing with various substrates such as alcohols and methylated nitrogen compounds, and to reduce sulfate in the presence of acetate. Isolated from sludge of an anaerobic digester run at 58 degrees C. Thermacetogenium phaeum is a strictly anaerobic, homoacetogenic bacterium. It is exceptional because it can use the homoacetogenic Wood-Ljungdahl (CO- dehydrogenase) pathway both for acetate formation and acetate oxidation. Acetate oxidation is possible only in syntrophic cooperation with a methanogenic partner which maintains a low hydrogen and/or formate concentration in the coculture. With this, the bacterium operates close to the thermodynamic equilibrium of substrate conversion, similar to other syntrophically fermenting bacteria such as Syntrophomonas wolfei the genomes of which have been sequenced as well in the recent past.