FIG 5.

Influence of hydrogen oxidation on the growth of Beggiatoa sp. 35Flor. Beggiatoa sp. 35Flor protein levels were measured as a substitute for filament biomass in hydrogen-supplemented (black bars) and -unsupplemented (white bars) oxygen-sulfide gradient cultures. The cultures were grown in the presence of a low sulfide flux. The top agar from triplicate cultures was sampled weekly to determine the total protein content and the density of the accompanying Pseudovibrio sp. FO-BEG1 cells. Measured total protein amounts were subsequently corrected for the contribution of Pseudovibrio sp. FO-BEG1 protein, which accounted for 20% to 50% of the measured values (see Fig. S3 in the supplemental material).