Microbial Control

• Microbial control involves sterilization and disinfection
• Sterilization is the complete removal or destruction of all living organisms, which can be achieved through physical and chemical methods
• Physical methods of sterilization include:

  • Applicator of heat
  • Cold temperature
  • Radiation
  • Trituration/grinding
  • Mechanical shaking/agitation
  • Use of ultrasonic
• Applicator of heat methods for sterilization:

  1. Moist Heat Method:

  • Principle: to kill microorganisms by coagulating
  • Methods: boiling, autoclave (needs 120°C under pressure for 15 minutes), Arnold Sterilizer (flowing steam or tyndallization at 100°C for 36 minutes for 3 consecutive days), inspissation (75-80°C for 2 hours for 3 consecutive days), pasteurization (used for sterilizing milk and milk products)

  2. Dry Heat Method:

  • Oven temperature: 160-170°C
  • Methods: flaming test tubes, cremation, incineration (flaming ashes at 300-400°C)
• 2 methods:

  •LTH (Low Temperature Holding) – Batch Method

  -(62°C for 30 mins)

  •HTST (High Temperature Short Time) – apply for 72°C for 15 seconds)
• 2. Dry Heat Method

  Methods:

   Oven Temperature: 160°C -170°C

  Time of Exposure: 1hr- 30 mins up until 2hrs

   Flaming – test tubes

   Cremation

   Incineration – flaming ashes 300-400°C

  Physical Methods for Removal

  •Filtration

  •Lyophilization