Culture Media Preperation

Question 1

medium with the exact composition and amounts of the individual amino acids, vitamins, growth factors, and other components that make it up
are not exactly known

Answer 1

complex medium

Question 2

• Specific nutritional requirements for growth are known
• specific chemical composition is known and individual components weighed out exactly to make up the medium

Answer 2

Defined Medium

Question 3

Nutritional Requirements of Bacteria

Answer 3

1. Carbon Source
2. Energy Source
3. Nitrogen
4. Minerals
5. Vitamins and Growth Factors
6. Water

Question 4

two groups based on their carbon requirements
- obtain their carbon from organic compounds
such as polysaccharides, carbohydrates, amino acids,
peptides, and protein

Answer 4

Heterotrophs

Question 5

two groups based on their carbon requirements
- derive their carbon requirements from fixing carbon dioxide

Answer 5

autotrophs

Question 6

Energy Source: Bacterial cells
- derive their energy needs from the breakdown
of organic molecules by fermentation or respiration

Answer 6

Chemoorganotrophs

Question 7

Energy Source: Bacterial cells
- oxidize inorganic ions such as nitrate or iron to obtain energy to fix carbon dioxide

Answer 7

Chemolithotrophs

Question 8

Energy Source: Bacterial cells
- contain photosynthetic
pigments such as chlorophyll or bacteriochlorophyll
that convert solar energy into chemical energy by
the process of photosynthesis

Answer 8

Photoautotrophs

Question 9

Energy Source: Bacterial cells
- derive their energy requirements from photosynthesis, but their
carbon needs come from growth on organic molecules such as succinate or glutamate

Answer 9

photoheterotrophs

Question 10

essential element in biolog-
ical molecules such as amino acids, nucleotide bases, and vitamins

Answer 10

Nitrogen

Question 11

Example of nitrogen fixing bacteria

Answer 11

Rhizobium and Azotobacter

Question 12

• essential in bacterial metabo-lism because they are cofactors in enzymatic reactions and are integral parts of molecules such as cyto-chromes, bacteriochlorophyll, and vitamins

Answer 12

Minerals

Question 13

serve as coenzymes in metabolism

Answer 13

Vitamins and Growth Factors

Question 14

medium that allows
certain bacteria to grow but will inhibit others from
growing

Answer 14

selective medium

Question 15

contains substances that
cause some bacteria to take on an appearance that
distinguishes them from other bacteria.

Answer 15

differential medium

Question 16

original media used by Louis Pasteur

Answer 16

urine or meat broth

Question 17

Liquid medium is used for what?

Answer 17

diffuse growth

Question 18

Solid medium is used for what?

Answer 18

discrete colonies

Question 19

he cooked cut potato as early solid medium

Answer 19

Robert Koch

Question 20

he discovered agar from seaweeds and algae

Answer 20

Walther Hesse

Question 21

Classification of media based on consistency

Answer 21

Solid media
Semisolid media
Liquid media

Question 22

Classification of media based on consistency
- contains 2% agar
- Colony morphology, pigmentation, hemolysis can be appreciated

Answer 22

Solid media

Question 23

Classification of media based on consistency
- no agar
- For inoculum preparation, Blood culture, for the isolation of pathogens from a mixture.

Answer 23

Liquid media

Question 24

Classification of media based on consistency
- 0.5% agar

Answer 24

Semi solid medium

Question 25

Constituents Of Media

Answer 25

• Agar or agar- agar
• Peptone - mixture of partially digested proteins
• Yeast or meat extract
• NaCl
• Melting point : 98°C
• Solidifying point : 42°C
• % of agar : Solid media (2%)

Question 26

Classification of media based on function or property
S.E.E.D. T.I.C.S

Answer 26

• Simple media
• Enriched media
• Enrichment broth
• Selective media
• Indicator media
• Differential media
• Composite media
• Transport media

Question 27

Classification of media based on function or property
- Also called Basal medium
- Most commonly used in routine labs

Answer 27

Simple Media

Question 28

Classification of media based on function or property
- Blood, serum or egg added to the basal medium.
- To grow bacteria which are more exacting in nutritional requirements

Answer 28

Enriched Media

Question 29

• enriched medium often used to grow fastidious organisms and to differentiate bacteria based on their hemolytic properties

Answer 29

Blood Agar Media

Question 30

Classification of media based on function or property
- For mixed cultures or materials containing more than one bacterium
- Contains substances which stimulates wanted bacteria & inhibits unwanted
bacteria

Answer 30

Enrichment Broth (media)

Question 31

Classification of media based on function or property
- Substances added to a solid media to favour the growth of wanted bacteria

Answer 31

Selective Media

Question 32

Classification of media based on function or property
- used to culture non-fastidious microorganisms that do not need extra growth nutrients

Answer 32

composite media

Question 33

Classification of media based on function or property
– potato dextrose agar (PDA)
- Sabouraud Dextrose Agar (SDA)
– Fungi and yeast and also filamentous bacteria

Answer 33

Fungal Media

Question 34

Classification of media based on function or property
- Change in the colour of indicator with the growth of bacteria

Answer 34

Indicator Media

Question 35

Classification of media based on function or property
- To bring out differing characteristics of bacteria

Answer 35

Differential Media

Question 36

Classification of media based on function or property
- have buffer solutions containing carbohydrates, peptones and other nutrients (excluding growth factors) designed to preserve the viability of bacteria during transport without allowing them to multiply.

Answer 36

Transport Media

Question 37

MEDIA PREPARATION
CALCULATION

Answer 37

Using the formula: M1/V1 = M2/V2
– ratio and proportion