Azospirillum Medium w/ 0.17% Agar (Twin Pack) is recommended for cultivation of Azospirillum species. Azospirillum species grows luxuriantlly in presence of Malic acid. Dipotassium phosphate provides buffering effect and other inorganic salt ingredients provide necessary growth nutrients. Agar at 0.17% concentrations provides microaerophillic conditions necessary for nitrogen fixation by Azospirillum species.