Query: NC_008686:1960034 Paracoccus denitrificans PD1222 chromosome 1, complete sequence
Lineage: Paracoccus denitrificans; Paracoccus; Rhodobacteraceae; Rhodobacterales; Proteobacteria; Bacteria
General Information: This organism is commonly found in soil and sewage sludge. This organism is able to survive in both aerobic and anaerobic environments due to its ability to use both oxygen and nitrogenous oxides making it a popular model organism for the study of electron transfer and and energy conservation.
Subject: NC_015571:1265121 Porphyromonas gingivalis TDC60, complete genome
Lineage: Porphyromonas gingivalis; Porphyromonas; Porphyromonadaceae; Bacteroidales; Bacteroidetes; Bacteria
General Information: 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.