FIGURE 2.
Phenotypic characterization of different Azotobacter vinelandii strains containing deletions in anfO and/or vnfEN genes. (a) Strains expressing FeFe nitrogenase were cultured on Burk’s medium agar plates containing a fixed nitrogen source (+NH3) (plate 1) or under different diazotrophic growth conditions (–NH3) (plates 2–5). V and W were added to the growth media as indicated for each condition. Strains were cultured on agar plates for 5 days. (b) Relevant genes inactivated for each strain. Refer to Table S1 for a complete genotypic description of the strains indicated. The key observations are the reversal of the incapacity for diazotrophic growth observed for DJ2290 when W is added to the media (plate 3) or when vnfEN are inactivated in combination with a deletion in anfO (DJ2411 and DJ2480, plates 2, 4 and 5)