FIG. 1.

Effect of 2,3-dihydroxybenzoic acid (DHB) on different E. coli strains. Colored precipitate formation in E. coli by CueO, CuCl₂ and 2,3-dihydroxybenzoic acid in strains GR1 (ΔcueO::cat) and wild-type (Wt) W3110. Overnight cultures grown in Luria-Bertani medium were diluted 1:500 into minimal medium, and grown overnight, diluted 1:500 into fresh minimal medium with 500 μM CuCl₂ added to all cultures, 2,3-dihydroxybenzoic acid was added where indicated, and growth at 37°C was continued for 16 h.