FIG 3.
Polyphosphate accumulation alters expression of peptidoglycan biosynthesis genes and reduces biofilm formation. (A, B) The ppx1::Tn mutant (A) and the ppk2::Tn mutant (B) were incubated in Sauton's medium lacking detergent for 5 weeks, and biofilms were assessed by crystal violet staining (*, P < 0.05 relative to the wild type; n = 3). OD600, OD at 600 nm. (C) RT-PCR of M. tuberculosis genes related to peptidoglycan biosynthesis during mid-log phase of growth. The CT of each gene was normalized to that of the housekeeping gene sigA in each strain, and this value was subtracted from the similarly normalized CT of each gene in the wild-type strain to yield the change in CT (ΔCT). Open bars, ppk2::Tn mutant; gray bars, ppx1::Tn mutant; error bars, SDs. *, P < 0.05 relative to the wild type; n = 3.