Query: NC_014100:172452 Caulobacter segnis ATCC 21756 chromosome, complete genome
Lineage: Caulobacter segnis; Caulobacter; Caulobacteraceae; Caulobacterales; Proteobacteria; Bacteria
General Information: Isolation: Soil; Temp: Mesophile; Habitat: Fresh water. Caulobacter segnis strain ATCC 21756 is a prostheca-less bacterium belonging to the genus Caulobacter; it was isolated from soil although its habitat is considered to be fresh-water. The absence of a stalk in this genus makes this an interesting bacterium to study.
Subject: NC_012560:4311906 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.