Use of reducing compounds in the cultivation of Azospirillum sp

Attempts were made to grow the micro-aerophilic N2-fixing bacterium Azospirillum sp. in complete liquid medium by incorporating some reducing agents. Ascorbic acid, glutathione and Na-thioglycollate stimulated while methylene blue inhibited the growth and N2-ase activity. In complete liquid medium, Na-thioglycollate and ascorbic acid increased the N2-ase activity with increasing concentration up to 800 micrograms/ml. With glutathione, growth of the bacterium was increased markedly but N2-ase activity was repressed below 200 micrograms/ml. The possibility of employing these compounds for the cultivation of Azospirillum in complete liquid medium seems to be indicated.