Query: NC_012560:603447 Azotobacter vinelandii DJ, complete genome
Lineage: Azotobacter vinelandii; Azotobacter; Pseudomonadaceae; Pseudomonadales; Proteobacteria; Bacteria
General Information: This organism was first isolated from the soil in Vineland, New Jersey, although it is found worldwide. It is a large obligate aerobe that has one of the highest respiratory rates of any organism. Azotobacter vinelandii also produces a number of unusual nitrogenases which allow it to fix atmospheric nitrogen to ammonia, a compound it can then use as a nitrogen source. It protects the oxygen-sensitive nitrogenase enzymes through its high respiratory rate, which sequesters the nitrogenase complexes in an anoxic environment. This organism has a number of unusual characteristics. Under extreme environmental conditions, the cell will produce a cyst that is resistant to dessication and is surrounded by two capsular polysaccharide layers. This organism produces two industrially important polysaccharides, poly-beta-hydroxybutyrate (PHB) and alginate. PHB is a thermoplastic biopolymer, and alginate is used in the food industry. Alginate is also used by the pathogen Pseudomonas aeruginosa to infect the lungs of cystic fibrosis patients.
Subject: NC_010161:1598000 Bartonella tribocorum CIP 105476, complete genome
Lineage: Bartonella tribocorum; Bartonella; Bartonellaceae; Rhizobiales; Proteobacteria; Bacteria
General Information: This organism was isolated from the blood of wild rats and from fleas obtained from wild rats. Transmission of these organisms is often through an insect vector. Once in a host, this intracellular pathogen is internalized by an actin-dependent mechanism, and primarily targets endothelial cells, although other cells can be infected. The proliferation of the vascular endothelium (bacillary angiomatosis) is characterisitic of Bartonella infection and results in multiplication of the bacterium's host cells. Infected macrophages are stimulated to release vascular endothelial growth factor (VEGF) and interleukin 1 beta, both of which promote angiogenesis. Endothelial cells are also stimulated to grow and divide by direct contact with bacterial cells. In addition, programmed cell death (apoptosis) of endothelial cells is inhibited, combatting a common mechanism eukaryotic cells use to deal with bacterial infection. Other pathogenicity factors include pili and outer membrane adhesins for attachment to host cells. This organism is genetically related to Bartonella elizabethae which was isolated from a case of endocarditis in a human.