One of the most versatile and widely studied diazotrophs is Azotobacter vinelandii, which has a diversity of features that are of interest to several scientific communities. In addition to having ...three distinct nitrogenases encoded by different genes, A. vinelandii is the most aerotolerant of free-living (non-plant associated) diazotrophs. Members of this species also produce alginates, siderophores, and can form dormant-stage cysts (for review, see Kennedy et al., 2005). A. vinelandii is a member of the gamma-proteobacteria and is therefore related to Escherichia coli. It is found in soils throughout the world and has been studied for >100 years with respect to its physiology, bio-chemistry, and genetics of nitrogen fixation and related aspects of metabolism (Kennedy and Bishop, 2004). In addition, the organism is easily genetically manipulated, easily mutagenized, and grows quickly in air in liquid culture or on plates, forming single well-defined colonies.
PDF
