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_002950:115917 Porphyromonas gingivalis W83, complete genome
Lineage: Porphyromonas gingivalis; Porphyromonas; Porphyromonadaceae; Bacteroidales; Bacteroidetes; Bacteria
General Information: This strain (also known as HG66) is virulent in a mouse model and has been extensively studied. It was originally isolated by H. Werner in the 1950s in Bonn, Germany, from an unknown human infection. Associated with severe and chronic periodontal disease. This organism is associated with severe and chronic periodontal (tissues surrounding and supporting the tooth) diseases. Progression of the disease is caused by colonization by this organism in an anaerobic environment in host tissues and severe progression results in loss of the tissues supporting the tooth and eventually loss of the tooth itself. The black pigmentation characteristic of this bacterium comes from iron acquisition that does not use the typical siderophore system of other bacteria but accumulates hemin.Peptides appear to be the predominant carbon and energy source of this organism, perhaps in keeping with its ability to destroy host tissue. Oxygen tolerance systems play a part in establishment of the organism in the oral cavity, including a superoxide dismutase. Pathogenic factors include extracellular adhesins that mediate interactions with other bacteria as well as the extracellular matrix, and a host of degradative enzymes that are responsible for tissue degradation and spread of the organism including the gingipains, which are trypsin-like cysteine proteases.