FIGURE 5.
Colony morphology and cell adhesion on solid surfaces of T. thermophilus and HB27 ΔpilQ::bleo mutants. A, cells of T. thermophilus HB27 wild type, HB27 ΔpilQ::bleo, and HB27 ΔpilQ::bleo carrying pDM12-pilQhis-Q (PilQ-Q), -pilQΔ25–34his (PilQΔ25–34), -pilQΔ25–64his (PilQΔ25–64), or -pilQΔ25–125his (PilQΔ25–125) were stab-inoculated on minimal medium plates containing 1% BSA and incubated for 3 days at 68 °C under humid conditions. Colony morphology was documented under a binocular microscope. Scale bar, 5 mm. B, for analyzing cell adhesion and twitching motility, medium was removed from the Petri dish, and adhered cells were visualized by Coomassie staining. Scale bar, 10 mm. C, electron micrographs of piliated HB27 and non-piliated HB27 mutant cells. Scale bars, 0.5 μm. D, statistical analyses of piliation of the indicated complementation mutant cells by electron microscopy.