Figure 4. Growth of methionine auxotrophic mutants with deletions in msrB and msrC on methionine and free Met-R-SO.

Bacteria were grown overnight in LB, harvested, washed and cultivated in M9 minimal medium supplemented with 13 µg ml⁻¹methionine (Met) or methionine-R-sulfoxide (Met-R-SO) (MOLISA), respectively, started at an optical density (OD₆₀₀) of 0.05. Growth of ΔmetCΔmsrB, ΔmetCΔmsrC and ΔmetCΔmsrBΔmsrC was observed by measurement of OD₆₀₀ every hour for nine hours of cultivation. Experiments were done in triplicates. Means are shown ± standard deviation.