FIG 1.
Urea analysis of key A. vinelandii strains. Shown above are the results of urea analysis of the A. vinelandii wild-type strain and the ΔureABC::Strr strain A. vinelandii AZBB030. (A) Results of an experiment where both strains were provided ∼1.2 mM urea at the time of inoculation, illustrating that A. vinelandii AZBB030 does not metabolize urea to an appreciable amount, while the wild-type strain depletes the urea from the culture during the first 24 h of growth. (B) The urea levels in A. vinelandii AZBB030 increase over time versus the wild-type strain, reaching levels in excess of 100 μM. All results and statistics are calculated based on triplicate samples.