Growth of cyclopropanecarboxylate-utilizing R. rhodochrous in minimal media containing various carbon sources. (A) Growth on 0.1% cyclopropanecarboxylate (•), 0.4% crotonate (○), 0.1% dl-3-hydroxybutyrate (□), or 0.1% dl-2-hydroxybutyrate (▪). (B) Growth on 0.1% cyclopropanecarboxylate (•), 0.1% citrate (○), or 0.1% glucose (□). OD580, optical density at 580 nm.