FIG. 4.

Effect of pH on growth on ethanolamine as the sole carbon source. Solid and open symbols represent growth of wild-type LT2 and the eutHΔ mutant, respectively. Individual curves indicate growth on different initial concentrations of added ethanolamine. Symbols: squares, 20 mM; circles, 10 mM; triangles, 8 mM; diamonds, 6 mM. Parts A and B describe the growth of wild-type and eutH mutant cells at pH 7.5. Parts C and D describe the growth of a eutH mutant at pHs 7 and 6.5. Wild-type cells show the same growth response at pHs 6.5 and 7 (not shown) as at pH 7.5 (above).