CONCLUSIONS
The key contribution of this study was the analysis of the response of
spores to sodium hypochlorite at the single-cell level. Using
single-cell techniques, our results revealed that sodium hypochlorite
inactivates spores by degrading the spore shell, damaging germination
proteins, breaking the permeability barrier, and damaging DNA. Upon
contact with spores, sodium hypochlorite reacted with the shell protein
layer, gradually dissolving the shell until it was completely degraded
and the attached budding proteins were destroyed. Subsequently, it
damaged the cortex, endosperm, and other structures of the spores,
destroying the permeability barrier and causing the spores to release
CaDPA. Sodium hypochlorite entered the interior of the spores, causing
damage to DNA and other substances and ultimately leading to spore
inactivation. In addition, with the prolongation of sodium hypochlorite
treatment, the inhibitory effects on germination and growth increased,
and damage to the structure of spores was more serious. Long-term sodium
hypochlorite treatment will continue to degrade other structures of the
spores and even the entire spore. The volume of the spores may decrease
dramatically after degradation, making the acquisition of single-cell
Raman spectra difficult; therefore, we controlled the treatment time to
less than 20 min. The effects of increasing the treatment time on spores
need to be investigated in the further.