Isolation of microbes , its all types, handling, advantages and dis advantages with video consoling

1. CONTENTS OF THIS Topic

2. Presented to: Mam Samia Tahir
Isolation of Microbes

3. 1- AREEBA IRFAN
(0103)
2- HAFSA HAMAYOUN
(0030)
5- SAMI ULLAH
(0110)
3. ZAKIA AKRAM
(0115)
4. WAJEEHA BATOOL
(0089)

4. WHAT ARE MICROBES?
A microorganism, or microbe, is a organism,
which may exist in its single-celled form or a
colony of cells.
 The study of microorganisms is called
microbiology
 a subject that began
with the discovery of microorganisms
in 1674 by Antonie van Leeuwenhoek ,
using a microscope of his own design

5. MICROBES ARE IMPORTANT
 INDUSTRIALLY- used in beverages,
Enzymes, Antibiotics.
 ENVIRONMENTALLY- They recycle
primary elements and maintain
sustainability of environment
 ECONOMICALLY- used to make cheese,
yogurt and is important in compost and
fertilizer production
 COMMERCIALLY- Production of Insulin
and a Growth Hormone Somatotrophin

6. ISOLATION OF MICROBES
Isolation is having mainly two strategies
1- From the environment by collecting the samples of free
living microorganisms from natural habitats
2- By sampling of microbes with desired characteristics
from specific sites such as found among the natural micro
flora
The site for isolation of microbes is decided by the type of
microbe one is interested in.

7. ISOLATION OF MICROBES
In microbiology, the term isolation refers to
the separation of a strain from a natural,
mixed population of living microbes, as
present in the environment, for example in
water or soil flora, or from living beings
with skin flora, oral flora or gut flora, in
order to identify the microbes of interest.

8. • Streak Plate Method
• Spread Plate Method
• Pour Plate Method or
Serial dilution method
• Laser Tweezers'
Plating techniques
(Classical Method)
Microscopic tool technology
(New Method)
METHODS FOR ISOLATION OF MICROBES

9. • Streaking is the process of spreading the microbial culture with an
inoculating needle on the surface of the media.
• Sterilize the inoculating needle by flame to make red hot and
allow it to cool for 30 seconds.
• The sample is streaked in such a way to provide series of dilution.
• purpose-thin out inoculum to get separate colonies.
• sub culturing can be done by streaking well isolated colonies from
streak plate to new plate.
STREAK PLATE METHOD

11. STREAK PLATE METHOD
• It is rapid and ideally a simple process of isolation dilution.
• The technique is done by diluting a comparatively large
concentration of bacteria to a smaller concentration.
• The decrease of bacteria should show that colonies are
sufficiently spread apart to effect the separation of the
different types of microbes.
• A sterile tool, such as a cotton swab or commonly an
inoculation loop is used.
• Aseptic techniques are used to maintain microbiological
cultures and to prevent contamination of the growth medium.

13. • The bacterial culture and liquid agar medium are mixed together.
• After mixing the medium, the medium containing the culture poured into sterilized
petri dishes ( petri plates), allowed solidifying and then incubated.
• After incubation colonies appear on the surface.
Pour plate method

14. • The number of microorganisms present in
the particular test sample is determined
using the formula:
1. CFU/mL= CFU * dilution factor * 1/aliquot
POUR PLATE METHOD
Uses:
The pour plate technique can be used to determine the number of
microbes/mL in a specimen. It has the advantage of not requiring
previously prepared plates, and is often used to assay bacterial
contamination of food stuffs.

15. Microorganism are trapped beneath the surface of medium
hence surface as well as subsurface
Colonies are developed which makes the difficulties in
counting the bacterial colony.
Tedious and time consuming method, microbes are
subjected to heat shock because of liquid
Medium maintained at 45℃.
Unsuitable- Psychrophile
Disadvantages of Pour Plate Method

17. Spread plate method
This is the best method to isolate the pure colonies.
• In this technique, the culture is not mixed with the agar medium. Instead it is mixed with
normal saline and serially diluted.
• 0.1 ml of sample taken from diluted mixture, which is placed on the surface of the agar plate
and spread evenly over the surface by using L-shaped glass rod called spreader.
• Incubate the plates
• After incubation, colonies are observed on the agar surface.

19. 1-It is a simple method.
2. In this method only surface colonies are formed.
3. Micro-organisms are not exposed to higher
temperature
ADVANTAGES

20.  laser tweezers offer a non-contact method for selecting single cells and
trans locating them from one microenvironment to another.
 Optical tweezers have been used to move single E. coli cells into individual
chambers in a micro-chamber array.
 Single yeast cells have been optically manipulated in a nutrient gradient,
created within a microfluidic device
 The isolation of single cells using optical tweezers in combination with three
different cell isolation devices
- a hollow glass micro needle channel
- a PDMS-based device
- a device inscribed in fused silica
LASER TWEEZERS

21. Useful for isolating slow
growing bacteria &
organisms present in less
number.
Cell is isolated from
microscopic field & moved
away from mixture of cells.
Consists of an inverted
light microscope equipped
with infrared laser &
micromanipulation device.
THE LASER TWEEZERS

22. Mixed
Sample in
Capillary tube
Focus laser
beam
Traps a
single cell &
drags down
the optically
trapped cell.
Cell moves
away from
contaminants
Capillary is
severed
Cell is
flushed into a
sterile
medium

23. It is mandatory that aseptic techniques be followed when experimenting with
microorganisms. Compared to spread plate and pour plate techniques, streak plate is
found to be the most efficient and also the easiest way to isolate bacterial colonies. Pure
cultures of three types of bacteria that were obtained included Staphylococcus aureus
(rod-shaped and Gram positive), Bacillus cereus (cocci-shaped and Gram positive) and
Escherichia coli (rod-shaped and Gram negative).
CONCLUSION

24. THANKS FOR LISTENING US
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