<p>Sporulation of <i>B</i>. <i>subtilis</i> strains was induced by the exhaustion method, and spores were collected in DSM after 48h. Spores were labeled with OmpC antiserum followed by Cy3-labeled goat anti-chicken IgG. Spores were visualized by phase-contrast (PC) and immunofluorescence (IF) microscopy.</p