FIG 7.

Growth kinetics of S. meliloti strains on M9 mineral medium containing γ-butyrobetaine as the carbon source. (A) Growth behavior of wild-type S. meliloti strains. (B) Growth behavior of wild-type and mutant strains of S. meliloti Rm2011. All cultures were successfully pregrown in M9 with 10 mM succinate as the carbon source, washed twice, and finally inoculated at an OD₆₀₀ of 0.08 in M9 medium containing 10 mM γ-butyrobetaine. OD₆₀₀ was continuously recorded by an automated growth curve analysis system (Bioscreen-C; Thermo Fisher Scientific). Values correspond to the averages from three replicates. Cultures were supplemented with 5 μM biotin.