To confirm the effect of sodium hypochlorite on the surface topography and morphology of spores, groups of spores treated with sodium hypochlorite for different times were characterized separately using AFM. Most of the untreated spores had a relatively rough outer surface (Figure 4 (a) ), with some individuals showing shallow ridges on the surface. After sodium hypochlorite treatment, the external surface of the spore was obviously changed; the surface of the spore individual was uneven and had protrusions consistent with shell protein retention after 5 min. The surface of the spore individual treated for 10 min was extremely smooth, with a few attachments. After treatment for 15 min, obvious ridges appeared on the spore surface, holes of different sizes were detected, and there were many crystal-like attachments around the spore. After 20 min, it became smoother, the individual spores became significantly smaller, and some spores had gaps on the surface (Figure 4(b)–(e) ). Sodium hypochlorite treatment caused obvious damage to the surface morphology and morphological
Figure 4 AFM images of individual spores treated with sodium hypochlorite for different times. (a) 0 min; (b) 5 min; (c) 10 min; (d) and (e) 15 min; (f) 20 min. (Picture size of individual spores: 2.5 μm, scale bar: 500 nm; picture size of local details of spores: 500 nm, scale bar: 100 nm)