FIG 2.

Salvaged cobamides are readily provisioned. (A) Illustration of cobamide archetypes. (B) Exponential growth rates of salvagers (Sal, blue) and dependents (Dep, gray) in glycerol minimal medium with various additions (10 nM each). The strains were cultured alone (mono) or together (co, initial ratio: 1:1). Global means are shown as open circles, and biological replicates are shown as dots. The technical precision of growth rate estimates was approximately ±0.025 h⁻¹ (see Materials and Methods for details) (N = 3). (C) Proliferation of cocultured salvagers (blue) and dependents (gray). The initial ratio was 1:1 (N = 3). Abbreviations: Cbi, incomplete, nonfunctional cobamide precursor cobinamide; LL, lower ligand, a required component of a cobamide; Cob, complete, functional cobamide; B12, vitamin B₁₂; DMB, 5,6-dimethylbenzimidazole, the lower ligand of B₁₂; b.u., bacterial units (see Materials and Methods for details).