Gamma Irradiation Effectively Kills Anthrax Spores: Mechanism and Applications

Anthrax spores (Bacillus anthracis) are highly resistant to heat, chemicals, and UV radiation. However, gamma rays (high-energy ionizing radiation) penetrate the spore coat and cause lethal DNA damage.

Mechanism

• Gamma photons ionize water → hydroxyl radicals → DNA double-strand breaks, base damage, cross-links.
• Spore DNA repair mechanisms are overwhelmed; genetic integrity lost → inability to germinate/replicate.

Applications

• Sterilization of medical devices, pharmaceuticals, tissue grafts.
• Decontamination of facilities, mail, soil.
• Food irradiation (approved for spices, meats, produce).

Gamma irradiation is a validated, reliable method for anthrax spore inactivation, used in biodefense and public health preparedness.