Query: NC_007426:205390 Natronomonas pharaonis DSM 2160, complete genome
Lineage: Natronomonas pharaonis; Natronomonas; Halobacteriaceae; Halobacteriales; Euryarchaeota; Archaea
General Information: Isolated from Lake Gabara in Egypt. Extreme haloalkaliphilic archeon. Natronomonas pharaonis is able to survive at high salt and pH conditions which results in limited nitrogen availability through ammonium. In order to compensate for this, Natronomonas pharaonis has developed three systems to promote nitrogen assimilation: direct uptake of ammonia, uptake of nitrate, and uptake of urea. Another problem with high pH environments is the use of a proton gradient for the generation of ATP, which other alkaliphiles have adapted to by substitution of sodium ions for protons. However, this organism utilizes protons for ATP generation as determined by experimental data.
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.