YmdB inhibits biofilm formation. (A) Inhibition of biofilm formation by YmdB overexpression. E. coli cells containing either pCA24N (−gfp) or ASKA-ymdB (−) were grown at 37°C for 24 h in LB medium containing 0 to 10-1 mM IPTG. Biofilm formation was analyzed, and mean values calculated (n = 10, p = 0.05). (B) Western blot analysis of YmdB expression levels. Total cellular proteins from the cells described in (A) were reacted with antibodies against YmdB or S1. Changes in YmdB protein levels from ASKA-ymdB induced by IPTG were determined relative to the levels of chromosomally-encoded YmdB protein derived from pCA24N (-gfp) vector-containing cells (indicated below).