BIOTECHNOLOGY NOTES
CULTURE AND IDENTIFICATION OF MICROORGANISMS
Topic : Methods of Sterilization – Physical and Chemical Methods
Introduction : Microorganisms play an important role in causing infection and
contamination. Therefore, Sterilization is an important technique in
microbiology which helps to remove or destroy microorganisms from materials
or surfaces.
Definition : Sterilization is an effective method, or a process used to kill all the
vegetative spores and disease-causing microorganisms. Sterilization
deactivates microorganisms including bacteria, spores, fungi, and unicellular
and other biological agents that are present in food products or on any certain
surface of the object.
It can be achieved by both physical, chemical, and other effective methods that
inhibit growth or are free from food products, fluids, objects, solid materials,
food packaging materials, raw materials, and other different products.
Importance of Sterilization :
It prevents the contamination of instruments and areas in the pharmaceutical industry.
, It is used in the preparation process of cultures and other microbiology experiments.
It is used in the food industries such as canning, and high-pressure methods.
Methods of Sterilization :
In order to completely eradicate microorganisms, sterilization techniques
involve classification of sterilization which include the following :
1. Physical Sterilization
It is method of sterilization to destroy the microorganism by using physical
methods like dry and wet heat, filtration and radiation. In these method wet or
moist heat considered to be the most effective method to sterilize the
glasswares.
By Using Heat
The most effective and reliable method of the sterilization process. There are
two methods by using heat-dry heat and moist heat.
Dry heat
Flaming : In this method heating instruments over the fire until they
become hot in red. Instruments that are used such as point of forceps,
Spatulas, inoculating loops, and Wires.
Incineration : It is a process that involves the combustion of organic
substances contained in waste materials. Items such as contaminated
cloth, animal carcasses, and pathological material. PVC and polythene can
be dealt with.
Hot air oven : Hot air ovens are the electrical devices used for
sterilization. The oven uses dry heat to sterilize items. Generally, they can
be set at minimum to maximum temperature from 50˚C to 300˚C. The
thermostat is present to control the temperature. This is the most widely
used method of sterilization by dry heat.
CULTURE AND IDENTIFICATION OF MICROORGANISMS
Topic : Methods of Sterilization – Physical and Chemical Methods
Introduction : Microorganisms play an important role in causing infection and
contamination. Therefore, Sterilization is an important technique in
microbiology which helps to remove or destroy microorganisms from materials
or surfaces.
Definition : Sterilization is an effective method, or a process used to kill all the
vegetative spores and disease-causing microorganisms. Sterilization
deactivates microorganisms including bacteria, spores, fungi, and unicellular
and other biological agents that are present in food products or on any certain
surface of the object.
It can be achieved by both physical, chemical, and other effective methods that
inhibit growth or are free from food products, fluids, objects, solid materials,
food packaging materials, raw materials, and other different products.
Importance of Sterilization :
It prevents the contamination of instruments and areas in the pharmaceutical industry.
, It is used in the preparation process of cultures and other microbiology experiments.
It is used in the food industries such as canning, and high-pressure methods.
Methods of Sterilization :
In order to completely eradicate microorganisms, sterilization techniques
involve classification of sterilization which include the following :
1. Physical Sterilization
It is method of sterilization to destroy the microorganism by using physical
methods like dry and wet heat, filtration and radiation. In these method wet or
moist heat considered to be the most effective method to sterilize the
glasswares.
By Using Heat
The most effective and reliable method of the sterilization process. There are
two methods by using heat-dry heat and moist heat.
Dry heat
Flaming : In this method heating instruments over the fire until they
become hot in red. Instruments that are used such as point of forceps,
Spatulas, inoculating loops, and Wires.
Incineration : It is a process that involves the combustion of organic
substances contained in waste materials. Items such as contaminated
cloth, animal carcasses, and pathological material. PVC and polythene can
be dealt with.
Hot air oven : Hot air ovens are the electrical devices used for
sterilization. The oven uses dry heat to sterilize items. Generally, they can
be set at minimum to maximum temperature from 50˚C to 300˚C. The
thermostat is present to control the temperature. This is the most widely
used method of sterilization by dry heat.
