Microbial Control -Method and Dynamics of Sterilization

1. {METHOD AND DYNAMICS OF STERILIZATION}
Presented By
Pranoti Ajay Atey
MSc Biotech (Semester-2)
DEPARTMENT OF BIOTECHNOLOGY
Dr. Ambedkar College, Dikshabhoomi, Nagpur

2. • Microbial control can be defined as inhibition or prevention of growth of microorganisms.
• Primary target of microbial control are microorganisms (contaminants)capable of causing
infection or spoilage.
• The method used outside the body are designed to result four possible outcomes :-
a) STERILIZATION
b) DISINFECTION
c) ANTISEPSIS
d) DECONTAMINATION

3. • A flowchart summarizes the major application and aim of microbial control:-

4. STERILIZATION
• The process that destroys or remove all the viable microorganisms, including viruses.
• Material subjected to the process are said to be sterile.
• Generally reserved for inanimate objects.
• Method can be divided into two broad categories
a) PHYSICAL METHOD
b) CHEMICAL METHOD

5. PHYSICAL
METHOD
Sunlight Heat Radiation filtration

6. SUNLIGHT :-
• Sunlight’s heats results into evaporation of moisture
or water molecule
• Results in drying the objects
• Hence doesn’t provide suitable atmosphere for
microorganism to survive
HEAT :-
• Dry heat- Heat without any type of moisture
Ex. Incineration, Hot Air Oven
• Moist heat- moisture and water used as the aim of
sterilization
Ex. Autoclave
RADIATION:-
• Also known as cool sterilization method
• Two Type of radiations 1)Ionizing
2) Non-Ionizing
• Ionizing method is more powerful as compared to
non- ionizing method.
• Ex. Electromagnetic waves, α-rays, Gamma rays, X-
rays
FILTRATION:-
• Works on the basic principle of the size of
microorganism
• Organism with smaller pore size will pass through the
filtrate and bigger one will remain above as residue.
• Ex. Earthenware Asbestos, Filtration membrane

7. CHEMICAL METHOD :-
Chemical microbial agent should posses these desirable qualities:-
1. Rapid action even in low concentration,
2. Solubility in water or alcohol and long term stability,
3. Broad spectrum microbicidal action,
4. Penetration of inanimate surface,
5. Resistance to becoming inactivated by organic matter,
6. Non-corrosive and non-staining properties,
7. Sanitizing and deodorizing properties and
8. Affordability and ready availability.

8. ALCOHOL-
Mode of action:- Dehydration of cells, Disruption of
membrane, coagulation of protein
Ex. Ethanol, Methanol, Isopropyl alcohol
Demerit :- Flammable
ALDEHYDE-
Mode of action:- Alkylation of amino and carboxyl group,
Damaging the nucleic acid
Ex. Formaldehyde
Demerit :- unstable, limited application, Slow rate of action
PHENOLIC-
Mode of action:-Damaging the cell membrane, Precipitation
or coagulation of protein
Ex. 5% phenol, 5% Cresol, 5% Lysol
Demerit:- Poor solubility, expensive
HALOGENS-
Mode of action:-Works as oxidizing agent
Ex. Chlorine, Bleach
Demerit:- Unstable in sunlight, has residual effect
HEAVY METALS-
Mode of action-Precipitation of protein and Oxidizing agent
Ex. AgNO3
Demerit:-Discolors skin
SURFACTANTS-
Mode of action- Simple soap or detergent on Animate or
Inanimate surface results into change in surface tension
Demerit:-only limited for removal of soil, oil and debris.

9. In the near future, the main challenge is to make sterilization process
1) More Reliable
2) Reusable
3) Non-Polluting
4) Cost effective
5) Less time consuming
6) Better Availability
at hospitals, pharmaceutical companies, drug industries, food processing
plants and laboratories.

10. REFERENCE :-
• https://www.youtube.com/watch?v=stvOgtPD1hs&list=WL&index=2&t=0s
• https://www.youtube.com/watch?v=C3CJYMi9A38&list=WL&index=2
THANK YOU