Figure 2.

Nitrogenase activity of azotobacters. Nitrogenase activity of transgenic and wild‐type azotobacters was evaluated by acetylene reduction assay. Azotobacter strains were grown in Burk's nitrogen‐free medium for 48 h. The cells were pelleted, transferred to fresh Burk's nitrogen‐free medium tubes with rubber stopper, flushed with argon and replaced with acetylene. Reduction of acetylene to ethylene was estimated after 24 h. The values represent the mean of the triplicates in three independent experiments. The vertical bars on the histogram indicate standard error.