FIG 5.

The effect of ferredoxin-like proteins, FDH, and hydrogenases on uric acid degradation. (A) The effect of hydN and ygfS genes encoding a ferredoxin on uric acid degradation activity. (B) The amount of uric acid in the medium after a 24-h incubation. The ΔFDHs mutant strain lacks all (three) FDHs, and the ΔHYDs mutant strain lacks all (four) hydrogenases. (C and D) Urate levels in the spent medium (C) and cell growth (D) of the wild type, FDH single mutants, and fdhD mutant during a 24-h incubation. (E and F) Urate levels in the spent medium (E) and cell growth (F) of the wild type and FDH double- and triple-deletion mutants during a 24-h incubation. (G and H) The introduction of plasmid-borne fdhF restores the uric acid degradation activity (G) and cell growth (H), with uric acid as the sole nitrogen source.