FIG. 2.

TEM of P. aeruginosa strains. Magnification, ×18,090. (A) FRD875 (AlgT⁺mucA22 algD::xylE aacC1); (B) FRD440 (mucA22 algT::Tn501). TEM was performed by scraping individual colonies from plates cultured overnight and resuspending the samples in 15 μl of LB containing alpha lactalbumin carrier protein (500 μg/ml). Glow-discharged, Formvar-coated copper mesh grids were floated on this suspension for 2 min. The excess suspension was wicked off, and the grid was floated on a drop of 2% phosphotungstic acid for 1 min and wicked dry. TEM was performed on a Philips TEM 400 operated at 80 kV.