FIG 6.

Uptake of [¹⁴C]succinate by B. subtilis strains with various genetic backgrounds for dctB and dctA after aerobic growth of the strains on succinate. For transport measurements and growth experiments, the cells were grown in White minimal medium (24), which was enriched with 0.05% or 0.01% (wt/vol) yeast extract, respectively, and supplemented with 20 mM succinate. The transport rates and growth capabilities on succinate were determined for the B. subtilis 168 wild-type strain as a positive control, the wild-type strain plus plasmid-encoded DctA (pDctA, pMW1927) as a control for the addition of pDctA to B. subtilis cells, the DctB-deficient strain (DctB⁻), and the DctB⁻ strain supplemented with pMW1927. (A) Transport assays were performed at 37°C with 20 μM [¹⁴C]succinate. The transport rates are given in μmol × g [dry weight]⁻¹ × min⁻¹ and are the averages of at least three biological replicates. Error bars represent the standard deviations. (B) The bacterial growth is given as the final OD₆₀₀ after incubation in enriched White minimal medium at 37°C for 16 h.