FIG 5.

Growth of M. acetivorans strains in the presence of 0.2 mM sodium sulfide and amino acid supplements. Cultures of the OASS-OAHS-MA1715 triple-knockout (left) and OASS-OAHS double-knockout (right) strains were supplemented with 0.75 mM homocysteine (+Hcy), 2 mM cysteine (+Cys), 1 mM cystathionine (+cysth), or 2 mM methionine (+Met). Unsupplemented cultures (no supp.) are also shown. All the data points represent averages of the results of at least four independent experiments. The error bars reflect standard deviations. Prior to each experiment, the strains were grown for at least 12 generations under the reported assay conditions. The data for both unsupplemented growth experiments were replotted from Fig. 3.