Module 4 pt. 1

Question 1

increase in the number of cells or microbial
population rather than in the size of
individual cells

To increase the population of
microorganisms, their nutritional and
physical requirements must be provided.

Answer 1

Microbial Growth

Question 2

Factors affecting microbial growth

Answer 2

biochemical
factors (nutrition)

generation time

physical factors

Question 3

biochemical
factors (nutrition) (3)

Answer 3

– macronutrients
– micronutrients
– vitamins

Question 4

physical factors (7)

Answer 4

• pH
  – temperature
  – oxygen concentration
  – moisture
  – hydrostatic pressure
  – osmotic pressure
  – radiation

Question 5

supplying cells with chemical tools (nutrients) they need to make monomers of macromolecules that mainly comprise microbial cells

Answer 5

Microbial Nutrition

Question 6

extracellular substances that provide the microbial cell with materials to
➢ build protoplasm
➢ generate energy

Answer 6

Nutrients

Question 7

nutrients required in relatively larger amounts
nutrients required in lesser quantities

Answer 7

macronutrients

micronutrients

Question 8

any nutrient material prepared/used for the growth and cultivation of microorganisms in the laboratory

Answer 8

Culture Medium

Question 9

What are Culture Media for? (3)

Answer 9

1. for the growth and maintenance of microbial cultures
2. to favor the production of particular compounds
3. to study microbial action on some constituents of the medium

Question 10

Types of Culture Media
(based on physical state or consistency)

Answer 10

liquid

semi-solid

solid

Question 11

no solidifying agent

Inoculum preparation;
fermentation test

Nutrient Broth;
Lactose Broth

Answer 11

liquid

Question 12

with 0.1- 0.5% solidifying agent

Motility test

Sulfur Indole Motility (SIM) Medium

Answer 12

semi-solid

Question 13

with 1.5-2.0% solidifying agent

Colony morphology observation; hemolysis and pigmentation characterization

Nutrient
Agar; Blood Agar

Answer 13

Solid

Question 14

solid culture medium types (3)

Answer 14

plate
slant
deep

Question 15

complex polysaccharide (usually derived from
red algae)

• used as solidifying agent for culture media in
  Petri plates, slants, and deeps
• no nutritive value;
• not affected by growth of bacteria
• Liquefies at 100°C
• Solidifies at ~40°C

Answer 15

Agar

Question 16

Types of Culture Media
(based on chemical composition) (2)

Answer 16

Synthetic Medium (DEFINED)
ex. Glucose Inorganic Salt Phosphate

Complex Medium (NOT DEFINED)
ex. Nutrient Agar, yeast extract

Question 17

Types of Culture Media
(based on principal purpose, function, or application) (5)

Answer 17

general purpose

differential

selective

enrichment

assay

Question 18

• allows the growth of a specific type of
  microorganisms only and suppresses the growth of
  others
• contains selective agents/additives/toxic chemicals
  (salts, dyes, antibiotics, and other inhibitors)

extreme pH value or unusual carbon source to favor
growth of a particular organism

Thayer-Martin agar (Neisseria gonorrhoeae); NA
with penicillin (Gram-negative bacteria);

Answer 18

Selective Medium

Question 19

• can distinguish or differentiate visually one type
  of bacterium from another
• identifies microorganisms by the appearance of
  their colonies and exploits the ability of a particular microorganism to change the appearance
  of the medium
• with special reagents like pH indicators and dyes
• i.e. blood agar (Streptococcus species); MacConkey agar (E. coli and lactose fermenters)

Answer 19

Differential Medium

Question 20

contains general nutrients and 5% sheep blood.
It is useful for cultivating fastidious organisms and for determining the hemolytic capabilities of an organism.

Some bacteria produce exoenzymes that lyse red blood cells and degrade hemoglobin; these are called ___.

Answer 20

Blood agar

hemolysins

Question 21

Types of hemolysin (3)

Answer 21

β-hemolysis (beta hemolysis) -complete

Alpha-hemolysin - partial, has biliverdin

γ-hemolysis (gamma hemolysis) - none

Question 22

used to increase the number of microorganisms with unusual physiological characteristics

contains special nutrient(s) for the microbe of interest (i.e. cellulose, petroleum, blood) and inhibitory substances to suppress unwanted microorganisms

Blood agar, Cellulose Agar

Answer 22

Enrichment Medium

Question 23

used for the assay of vitamins, amino acids,
antibiotics, etc.; used for qualitative or
quantitative production of such a compound by
a microorganis

of prescribed composition

fermentation media, Triple Sugar Iron
Agar

Answer 23

Assay Medium

Question 24

• medium contains an indicator which
  changes its color when a bacterium
  grows in them
• i.e. Blood agar (also a differential
  media); Mac Conkey’s medium

Answer 24

Indicator Medium

Question 25

• medium containing any fermentable substances (i.e.
  glucose, arabinose, lactose, starch)
• consists of 1% of the sugar in peptone water

Answer 25

Sugar Medium

Question 26

• medium used for transporting
  samples (prevent microbial
  proliferation; maintain viability
  of microorganisms)

Stuart’s medium

Answer 26

Transport Medium

Question 27

medium used to provide additional information for
the identification of the bacterium

Answer 27

Biochemical Reaction Medium

Question 28

• These media are used to grow
  anaerobic organisms.
• e.g: Robertson’s cooked meat
  medium,

Answer 28

Anaerobic media

Question 29

• These media are used to grow
  aerobic organisms.
• e.g: Mannitol salt agar

Answer 29

Aerobic media