Figure 2.

Nitrogenase activity in Nostoc 7120 upon the addition of BMAA and various nitrogen sources. (a) Accumulated ethylene production (nmol C₂H₄) after the addition of 20 µM BMAA, DAB, Cys, or Glu, or 5 mM NH₄⁺. The graph displays mean values from one of the two experiments ± SE; n = 3. (b) Ethylene production (nmol C₂H₄ µg chl a⁻¹ h⁻¹) after addition of BMAA or NH₄⁺ at various concentrations to the BG11₀-grown Nostoc 7120 cells (20-h treatment). The bars denote mean values of three independent experiments ± SE; n = 3.