Bacterial Culture media,1st Sem MSc

1. BACTERIAL
CULTURE
MEDIA

2. INTRODUCTION
CULTURE MEDIA:-
 Robert Koch - Father of Culture media (Bacillus anthrax)
 Louis Pasteur – Liquid culture media
 Any liquid or solid preparation made specifically for the growth , storage , transport of micro organism or
other types of cells are known as culture media.
 Provides Artificial environment
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3.  Basic requirements –
1. Energy source
2. Carbon Source
3. Nitrogen Source
4. Salts like S, P, Cl , Na, K, Mg , Fe, Ca, trace elements like Cu.
5. PH 7.2 to 7.6
6. Growth Factors
7. Adequate oxidation and reduction potential.
 Importance – Determine type of organism, its origin, modification, transformation, cause of infectious disease ,its
diagnosis and cure.
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4. MEDIA USED FOR BACTERIAL CULTURE
Simple Media
Complex Media
Special Media
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5. SIMPLE MEDIA
 Basal media
 Used for cultivation for all types of bacteria
 Contains nutrient broth and nutrient agar
 Nutrient broth:-
1. Peptone
2. beef extract
3. NaCl
4. PH – 7
 Nutrient Agar:-2% of Agar
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6. COMPLEX MEDIA
 Media that contains some ingredients of unknown
chemical composition are complex media.
 Mainly used for growth of micro organism.
 Added ingredients – properties or providing special
nutrients – required for growth.
 Nutrients-casein hydrolysate/yeast extracts.
 Contains undefined components – peptone, yeast
extract and meat extract.
 Example- Tryptic soy broth, blood agar ,nutrient
broth/agar
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7. SPECIAL MEDIA
1. ENRICHED MEDIA
2. SELECTIVE MEDIA
3. DIFFERENTIAL MEDIA
4. TRANSPORT MEDIA
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8. ENRICHED MEDIA
 EXTRA NUTRIENTS- blood, serum, egg yolk in basal
media.
 Promotes growth of wanted bacteria and inhibits
unwanted bacteria.
 EXAMPLES :
 BLOOD AGAR : specially used for the growth of
Streptococci to demonstrate on Hemolysis.
 CHOCOLATE AGAR : used for culture of
Neisseria and H-Influenza.
 Selenite F Broth : isolation of Salmonella.
 Alkaline peptone broth : Inhibits vibrio cholera.
 Tetrathionate : inhibits coliform.
Blood agar
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9. SELECTIVE MEDIA
 Growth of particular bacteria.
 Media contains Antibiotics , Dyes and Chemicals.
 EXAMPLES :
 Thayer Martin Media: culturing Neisseria
bacteria.
 EMB AGAR : Promotes the growth of gram
_bacteria .
 Methylene Blue: promotes gram + bacteria.
EMB METHYLENE BLUE
THAYER MARTINA
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10. DIFFERENTIAL MEDIA
 Indicator Media
 Distinguish one organism from another growing
in same media.
 Presence of certain Dyes and Chemicals in media,
the organism will produce characteristic changes
or growth patterns that are used for
differentiation.
 EXAMPLES:
 Macconkey media : used to differentiate
lactose fermentation.
 Blood agar
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11. TRANSPORT MEDIA
 Essential solution buffers - carbohydrates, peptone,
nutrients (excluding growth factors).
 It preserves the viability of bacteria during transport
without allowing their multiplications.
 Aim: maintains specimen at its original state.
 EXAMPLES:
 STUARTS MEDIA: commonly used for
transporting specimens suspected of
having Gonococci.
 Amies media without charcoal: isolation of
Mycoplasma and Urea plasma.
Stuarts media
Amies transport
media
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12. CONCLUSION
BACTERIAL CULTURE MEDIA
SIMPLE COMPLEX SPECIAL
• Used for every
type
• Nutrient broth
&nutrient Agar
Eg:
Staphylococcus
Enterobacteriacea
e
• Growth of micro
organisms
• Nutrient
requirements
are unknown
• Eg: Blood agar ,
Tryptic soy
broth/Agar
Enriched media
Selective media
Differential media
Transport media
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