This document describes different types of culture media used to grow microorganisms. It discusses media categorized by consistency (solid, liquid, semi-solid), constituents (simple, complex, synthetic), purpose (enriched, enrichment, selective, indicator, differential, sugar, transport), and oxygen requirement (aerobic, anaerobic). Liquid media like broths are used to grow bacteria uniformly, while solid media containing agar are used for isolating colonies. Selective and enrichment media inhibit unwanted bacteria to isolate specific microorganisms. Indicator and differential media detect microbial properties through color changes.

1. TYPES OF CULTURE MEDIA
I . Based on consistency
a)solid media
b)liquid media
c)semi solid media
II . Based on constituents
a) simple media
b)complex media
c)synthetic media

2. III . Special media
a)enriched media
b)Enrichment media
c)selective media
d)indicator media
e)differential media
f)sugar media
g)transport media
IV . Based on oxygen requirement
a) Aerobic media
b) Anerobic media

3.  Physical state :
• Liquid media
• Solid media
• semi solid media
 LIQUID MEDIA : Ex : nutrient broth
Generally it is carried in tubes , bottles, flask
In liquid media , bacteria grow uniformly produces turbidity
No agar added
Inoculum are prepared
 SOLID MEDIA : Ex: nutrient agar
Agar plate is a petri dish contain 2% of agar
Agar is solidifying agent
 SEMI SOLID MEDIA
Useful for demonstrating bacteria motility
Ex : hugh & lefison’s oxidation fermentation

5. Based upon nutrient components :
 SIMPLE MEDIA :
• also known as BASAL MEDIA
• It supports mostly non fastidious bacteria
• Ex: nutrient broth , nutrient agar – peptone , yeast extract & Nacl when 2% of agar is added to
nutrient broth and nutrient agar
 COMPLEX MEDIA :
• other than basal media are called complwx media
• Special ingredients are required for growth of bacteria
• Ex : yeast and casein
 SYNTHETIC MEDIA :
• It is used for research purpose
• Composition of every is well known
• It is generally prepared from pure chemical substances
• Ex : peptone water

6. Based upon functional group
 ENRICHED MEDIA :
• This media is for fastidious microorganisms
• It includes like blood , serum , egg to basal media
Ex : blood agar ( streptococcus ) chocolate agar ( nessiaria)

7.  ENRICHMENT MEDIA :
• In this media nutrients are adjusted in such away that it
inhibits the growth of unwanted bacteria
• But permits required bacteria to grow
• It is liquid media
Ex : tetrathionate broth – for the isolation of salmonella
selenite broth – to inhibit coliforms
alkaline peptone water – for vibrio cholera

9.  SELECTIVE MEDIA :
• It is same as enrichment media but it exists in solid
form
• In this media nutrients are adjusted in such away that
it inhibits the growth of unwanted bacteria in the form
of colonies
• Here physical conditions are included such as
temperature , pH , gaseous requirements are adjusted
and made selective for growth of specific micro
organisms
Ex : Mac Conkey’s media – gram negative bacteria

11.  INDICATOR MEDIA :
• In this media contains indicator which changes color when bacterial
species grow in them
Ex : Wilson and blair medium :- Salmonella typhi reduces sulphite to
sulphate in the presence of glucose ( black metallic shine colonies )

12.  DIFFERENTIAL MEDIA :
• It distinguish between different types of bacteria based on some
characteristic reaction towards medium like hemolysis or
biochemical reactions
• So, that bacteria utilizes them appear as differently colored
colonies which can be distinguished from each other
Ex : Mac Conkey’s media
It is designed to grow gram negative bacteria and differentiate them
for lactose fermentation .
1. Lactose fermenters – pink colonies
2. Non lactose fermenters – colorless colonies

14.  SUGAR MEDIA :
• In this we use 1% sugar + peptone water with suitable
indicator
• In this DURHAM’S tube is used it is kept inverted in
the tube containing medium to detech gas production
• Fermentation is carried out which is important for
identification of micro organisms

16.  TRANSPORT MEDIA :
• Media derived specially for transport of delicate micro
organisms
• Ex : Nessieria gonorrhoeae ( this may not survive the
time takes it may overgrow non pathogen e.coli and
pathogens like salmonella sp & shigella
• Ex : stuart’s transport medium , amines transport
media

18. IV . Based on oxygen requirement :
AERBOIC MEDIA : used for growing aerobic
organisms
Ex : Mac conkeys broth
ANEROBIC MEDIA :
Use for growing anaerobic organisms
ex : thioglycolate broth