Query: NC_016930:943000 Rickettsia philipii str. 364D chromosome, complete genome
Lineage: Rickettsia philipii; Rickettsia; Rickettsiaceae; Rickettsiales; Proteobacteria; Bacteria
General Information: Rickettsiae are obligate intracellular Gram-negative bacteria mostly found in arthropods, some of which cause mild to severe diseases in humans. Spotted fever group rickettsiae (SFGR) cause disease in humans. R .philippi strain 364D, an SFGR, was isolated in 1966 from Dermacentor occidentalis ticks collected in Ventura county, California, and since then 364D has been detected in up to 11% of D. occidentalis from 8 California counties. It has now been recognized as causing eschar-associated illness.
Subject: NC_018870:427357 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.