Biotechnological uses of Azotobacter vinelandii: Current state, limits and prospects

Azotobacter vinelandii is a bacterium obligate aerobe able to fix nitrogen and grow under microaerophilic conditions. This microorganism has remarkable cellular machinery with the ability to biosynthesize three molecules of important biotechnological and biomedical applications: the extracellular polysaccharide alginate, the intracellular polyester poly-beta-hydroxybutyrate (PHB) and siderophores compounds. Alginate and PHB have been produced in shake flasks and bioreactors (at laboratory scale) under different environmental and nutritional conditions. This mini-review gives a current overview on the application of wild-type and mutant's strains of A. vinelandii in bioprocesses to produce alginate or PHB. Scales of production implemented and fermentation strategies used as well as the potential limitations of the use of A. vinelandii cells are analyzed. Based on an approach that integrates molecular and bioengineering techniques, new experimental strategies to enhance the productivity of alginate and PHB from A. vinelandii are proposed.