Table 1.

Role of various factors in resistance of spores ofBacillus species to different treatmentsa

TreatmentEffect on resistance
α/β-Type SASPCore waterCore mineralsRepairSpore coatsSporulation conditions
Desiccation++?+/−b??
Dry heat+++/−+??
Wet heat+++++/−+
γ-Radiation(++)c?++??
UV radiation++d?++e
Alkylating agentsf++??++?
Formaldehydef++??++?
Glutaraldehydef??+++/−
Iodinef??+++/−
Peroxidesf, g++++?+?
  • a Assignment of the importance of resistance factors is largely based on work with B. subtilis, but there are also data on the importance of core water and minerals for spores of other species. Symbols: ++, major importance; +, some importance but not a major factor; +/−, minor importance but has some effect; −, no effect; ?, no data available. See references 10, 12, 15, 26, 38, 39, 42, 45, 52, 56, 93, 98, 99, 102, 113, 124, 125, 133, 135, 153, 165, 168, 169, 175, 176, 179, 180, 181, 182, 183, 185, 190, 191, 209a, and230.

  • b DNA repair is likely important in resistance to killing at very high vacuum.

  • c This is likely important in γ-radiation resistance, but this has not been shown by experiment.

  • d A low core water content may be important in ensuring that DNA is saturated with α/β-type SASP.

  • e Spore coats may play a minor role in resistance to UV-B and UV-A wavelengths (165).

  • f The relative impermeability of the spore core undoubtedly plays a role in resistance to all chemicals.

  • g Enzymes that detoxify peroxides are not important in spore peroxide resistance (21).