Fig 1.

Impaired use of alternative carbon sources by UTI89ΔcyaA and UTI89Δcrp. (A) MacConkey agar plate streaked with UTI89, UTI89ΔcyaA, and UTI89Δcrp. Growth of UTI89, UTI89ΔcyaA, UTI89Δcrp, and complemented mutants in modified M9 medium (B) and modified M9 medium lacking glucose (C). Mutant strains were complemented by uninduced expression of cyaA or crp from a Ptac promoter. Strains transformed with the empty vector pRR48 served as controls. Each curve reflects the means of results from a single experiment and is representative of at least three independent experiments performed in quadruplicate.