Fig. 2: F5882 nitrogen fixation capabilities compared to wild-type N. punctiforme.

Light microscopy of N. punctiforme (a) and mutant ΔF5882 (b), showing heterocyst formation. Black arrows point out representative heterocysts. c Nitrogen fixation rates using acetylene reduction assay in wild type and mutant, expressed as extracted chlorophyll a ml−1 culture. Error bars represent one standard deviation between triplicates.