Fig. 4

Nitrate respiration in TFA. Genetic organization of TFA nar genes (a). Anaerobic growth of TFA, measured by OD increase (b), in rich medium plus nitrate 20 mM (open squares), or in minimal medium in the presence of nitrate 40 mM (squares), 20 mM (triangles) or nitrate 20 mM plus nitrite 6 mM (circles). No growth was detected when nitrate was omitted from the growth medium (open circles). Nitrate consumption and nitrite production (c, solid and dotted lines, respectively) in the presence of nitrate 40 mM (squares), nitrate 20 mM (triangles) or nitrate 20 mM plus nitrite 6 mM (circles)