Photo taken by Richard Pau

Azotobacter vinelandii is a gamma-proteobacterium belonging to the family Pseudomonadaceae. Over the years, A. vinelandii has served as a model for biochemical analyses due to the extraordinary yield and quality of enzymes that can be isolated from this organism. Most recently these studies have been focused on the ability of A. vinelandii to fix diatmospheric nitrogen using three distinct nitrogenase systems under free-living conditions, a process that occurs in the presence of oxygen levels that typically inactivate the nitrogenase enzyme. A. vinelandii is also unusual in that, for reasons that are not clear, it increases the copy number of its chromosome up to 50-100 times during late log phase. In addition, it provides an ideal system in which to investigate the processes of cyst formation and xenobiotic degradation. Studies on these and other aspects of Azotobacter biology will be significantly enhanced by the provision of a finished and well-annotated genome sequence. Within the Pseudomonadaceae family only one of the three main genera has fully sequenced representatives (Pseudomonas). Provision of the complete A. vinelandii genome therefore also serves as one of the essential gold-standard phylogenetic anchor points for comparative genomics.