Cell aggregation and adhesion by E. coli C PNPase-defective strain. A. Growth curves of E. coli C-1a (pnp+; solid symbols) and E. coli C-5691 (Δpnp-751; open symbols) in different media (M9Glu/sup, diamonds; M9Glu, triangles) (left panel). Cell clumping by the C-5691 (Δpnp) strain led to deposition of ring-like aggregates on the flask walls (indicated by the arrow; right panel). The picture was taken in the late exponential phase (OD600 = 5–6). B. Cultures of strains carrying pBAD24 derivatives grown up to OD600 = 0.6-0.8 in M9Glu/sup at 37°C with aeration were harvested by centrifugation, resuspended in 0.04 vol M9 and diluted 25 fold in pre-warmed M9/sup with either 0.4% glucose (solid symbols) or 1% arabinose (empty symbols). Incubation at 37°C was resumed and growth monitored spectrophotometrically. Left panel: PNPase complementation. Right panel: suppression by RNase II.
Carzaniga et al. BMC Microbiology 2012 12:270 doi:10.1186/1471-2180-12-270