Figure 1. Phenotype of GlmS⁻ mutant E. coli.

(A) Growth of GlmS⁻ mutant E. coli under various media conditions. GlmS⁻ mutant E. coli (CKS1001, open circles) and GlmS⁻ mutant E. coli carrying ^E.cGlmS⁺p (closed circles) grown overnight in LB supplemented with 0.2% GlcNAc were diluted 50-fold in minimal media or media supplemented with 0.2% GlcNAc (open triangles) and grown for 24 hrs. Wild-type parental E. coli (CH1436, closed triangles) were grown in the same way in minimal media. Samples were taken at the indicated times for CFU determination on supplemented LB plates. (B) GlmS⁻ mutant (CKS1001) or parental wild-type E. coli (CH1436) carrying ϕhdeABp:lacZYA grown overnight in LB supplemented with 0.2% GlcNAc were diluted 50-fold in minimal media and grown for 5 hrs. β-galactosidase activity (A₄₂₀/min/ml) in the supernatants and lysed pellets was determined. (C) GlmS⁻ mutant bacteria (CKS1001) carrying ^E.cGlmS⁺pGFP or pGFP grown overnight in LB supplemented with 0.2% GlcNAc were diluted 50-fold in minimal media and cultured for the indicated times. Wild-type parental E. coli (CH1436) carrying pGFP was grown the same way in minimal media. Samples were taken at the indicated times, the supernatant (s) and pellet (p) fractions were isolated, and the fractions were separated by 12% SDS-PAGE for determination of GFP by Western blotting.