<i>bcpAIOB</i> allele-dependent competitive exclusion from an established community.

<p><b>A</b>) Biofilms were inoculated with the “established strain,” <i>Bt</i>-<i>Bp</i>1106a-1::<i>bcpI_Bt</i>_E264, constitutively expressing <i>rfp</i>, incubated for 24 hours, washed, and then re-inoculated with the “invading strain,” I. <i>Bt</i>E264 or II. <i>Bt</i>E264::<i>bcpI_Bp</i>_1106a-1, constitutively expressing <i>gfp</i>, re-incubated for 48 hours, washed, and then imaged by confocal microscopy. Images shown are of fluorescent and DIC channels merged, taken in a plane of focus approximately half way between the top and bottom of the biofilms. Scale bar = 32 µm. <b>B</b>) CLSM of representative RPF⁺ pillar structures. Images are from the same experiment as in A). Z stack image cross-sections were taken at 10 µm above the substratum. Scale bar = 10 µm. <b>C</b>) Single strain biofilms formed by <i>Bt</i>E264 and <i>Bt</i>E264::<i>bcpI_Bp</i>_1106a-1, constitutively expressing <i>gfp</i>, 24 hours post inoculation. Images shown are of fluorescent and DIC channels merged, taken in a plane of focus approximately half way between the top and bottom of the biofilms. Scale bar = 32 µm.