TABLE 1.

Biofilm thicknesses, active zone thicknesses, and oxygen penetration depths in P. aeruginosa colony biofilmsd

StrainBiofilm thicknessa (μm)Active zone thicknessb (μm)Oxygen penetration depthc (μm)
PAO1209 ± 37Not visible50.6 ± 1.2
AH298154 ± 2363 ± 1646.0 ± 5.3
PAO1(pMF335)NDND48.6 ± 7.3
PAO1(pAB1)298 ± 6060 ± 12ND
  • a Thickness was determined from GFP-expressing frozen cross sections as the perpendicular distance from the membrane interface to the outermost fluorescent material.

  • b The active zone dimension was measured as the width at the peak half-height of the GFP fluorescence intensity in a frozen cross section.

  • c Oxygen penetration depth was determined as the distance into the biofilm at which the first derivative of the oxygen concentration reached 5% of its maximum value.

  • d Data are means ± standard deviations. ND, not determined.