Chapter 6 - Azospirillum

Abstract

The genus Azospirillum belongs to the α-subclass of Proteobacteria and has been considered an important genus among the plant growth-promoting bacteria. The occurrence of Azospirillum species is widespread in the environment, including tropical, subtropical, and temperate regions; most of them were described from plant roots and soil samples. Some members of the genus Azospirillum are recognized as biofertilizers owing to their plant growth-promoting activities, such as the biologic nitrogen fixation, hormones production, phosphate solubilization, and siderophore production. Also, it has biocontrol activity of phytopathogens. All these features make some species of Azospirillum attractive for using in agricultural important crops. In this chapter an updated status of the genus Azospirillum and its role in agroecology is presented, including taxonomy, isolation and identification strategies, plant growth-promoting characteristics, biofilm formation, and root colonization, as well as the use as biofertilizer, abiotic stress tolerance induction, bioremediation, biofortification, and the activity as a biocontrol agent.