Fig. 5.

Nanomolar concentrations of CoCl₂and micromolar concentrations of AdoCbl affect cbtJexpression in S. meliloti. Cells were grown in M9-succinate medium, washed with 0.85% NaCl, and then inoculated into M9-succinate with 0 to 50 nM CoCl₂(A) or M9-succinate with 0 to 100 μM AdoCbl and no CoCl₂(B). After growth for 36 h, LacZ (β-galactosidase) activity was determined. The fusion strains were RmP110 (wild type), RmP831 (cbtJp::gfp-lacZfusion), and RmP833 (cbtJKLmutant with cbtJ::gfp-lacZfusion).