Single-cell analysis reveals microbial spore responses to sodium hypochlorite

Abstract

Abstract The effect of sodium hypochlorite on the internal structure of single spore was determined at the molecular level, as well as the effect on spores’ germination, growth and morphology. Bacillus subtilis (CMCC(B)63501) was characterized using the single-cell technique after exposure to 0.5% sodium hypochlorite solution. The results of laser tweezers Raman spectroscopy showed that sodium hypochlorite resulted in Ca2+-dipicolinic acid release and nucleic acid denaturation. Atomic force microscopy images showed that the surface of treated spores changed from rough to smooth, protein shells were degraded at 10 min, and the permeability barrier was destroyed at 15 min. The spore volume decreased gradually over time. Live-cell imaging showed that the germination and growth rates decreased with increasing treatment time, indicating that sodium hypochlorite was able to inhibit spore activity effectively. These results provide new insight into the response of live spores to sodium hypochlorite and demonstrate the application of various new single-cell analysis techniques.