The document discusses various terms used to describe the control of microorganisms, including sterilization, disinfection, decontamination, and the agents used for each such as disinfectants, antiseptics, and sanitizers. It also outlines the main methods used for microbial control, which are physical methods like heat and radiation, and chemical methods using selective and non-selective antimicrobial agents.

1. Dr. V. RAMESH
Assistant Professor & Head In-Charge,
Department of Botany,
Vivekananda College,
Tiruvedakam West – 625 234
Madurai.
CONTROL OF MICROBES

2. Basic terminology used in discussing the control of
microorganisms include:
1. Sterilization: Sterilization is the process of destroying
all living organisms and viruses. A sterile object is one free
of all life forms, including bacterial endospores, as well as
viruses.
2. Disinfection: Disinfection is the elimination of
microorganisms, but not necessarily endospores, from
inanimate objects or surfaces.
3. Decontamination: Decontamination is the treatment of
an object or inanimate surface to make it safe to handle.
4. Disinfectant: A disinfectant is an agents used to
disinfect inanimate objects but generally to toxic to use
on human tissues.

3. 5. Antiseptic:An antiseptic is an agent that kills or
inhibits growth of microbes but is safe to use on
human tissue.
6. Sanitizer: A sanitizer is an agent that reduces
microbial numbers to a safe level.
7. Antibiotic: An antibiotic is a metabolic product
produced by one microorganism that inhibits or kills
other microorganisms.
8. Chemotherapeutic synthetic drugs: Synthetic
chemicals that can be used therapeutically.
9. Cidal: An agent that is cidal in action will kill
microorganisms and viruses.
10. Static: An agent that is static in action will inhibit
the growth of microorganisms.

4. Surfaces.

7. METHODS OF MICROBIAL CONTROL
Physical methods Chemical methods
Heat Cold
Drying or Desiccation Filtration Radiation
Dry Heat
1. Flaming
2. Hot air Oven
3. Incineration
Moist Heat
1. Pasteurization
2. Boiling
3. Autoclaving
Ionizing
1. X rays
2. Gamma rays
UV
Microwaves
Non-selective Selective
Killing
Efficacy
DrugsChemotherapeutic agents or Antimicrobial agents
1. Phenols, 2. Alcohols,3. Surface active Agents, 4. Halogens, 5. Heavy Metals
6. Gases, 7. Chlorhexidine, 8. Alkyl Agents