Figure 5.

TEM of B. thuringiensis spores treated with different sporicidal chemicals for 30 min, imaged at 73,000 magnification and 27,000 magnification (inset). We labeled the structural layers of the spore as follows: green arrows: exosporium; black arrows: spore coat; blue arrows: cortex; and yellow arrows: core. (A) Untreated spore in water. (B) Spores treated with chlorine dioxide appear no different than control. (C) Spores treated with sodium hypochlorite are degraded, and the core is no longer electron-dense, indicating DPA release. (D) Spores treated with peracetic acid have a fragmented spore coat.