Types of Radiation in Microbial Control

Overview

• Two Types of Radiation: Ionizing and Non-ionizing
• Purpose: Both used as physical methods for microbial control
• Key Difference: Ionizing is more powerful than non-ionizing

Ionizing Radiation

Characteristics

• Types: X-rays and Gamma rays
• Power: Very high intensity
• Effect on DNA: Damages the entire double helix
  • Leads to mutations
  • Accelerates mutation rates leading to cell death

Advantages

• Penetration:
  • Can penetrate surfaces like paper and plastic
  • Useful for sterilizing items in packages
• Applications:
  • Used in sterilizing food (e.g., spices)
  • Common in the medical industry (e.g., plastic petri dishes, disposable wire loops, certain drugs, medical equipment)

Key Term

• Electronically Pasteurized: Refers to gamma radiation used in food sterilization
• Raíidura: Symbol indicating food has been treated with gamma radiation

Non-Ionizing Radiation

Characteristics

• Type: UV Light
• Effect on DNA:
  • Creates thymine dimers
  • Leads to mutations or repair-induced mutations

Limitations

• Penetration:
  • No penetration depth
  • Effective only on surfaces

Applications

• Disinfection:
  • Used for surfaces like in surgical suites, nurseries
  • Employed in water treatment and fish tanks
  • Portable UV lamps available for camping and outdoor activities

Conclusion

• Ionizing Radiation: Powerful, deep penetration, used for sterilizing packaged goods
• Non-Ionizing Radiation: Surface-level, commonly used in disinfection

These notes provide a summary of Dr. Rowe's lecture on the types of radiation used for microbial control, highlighting key points on their characteristics, applications, and limitations.