PHMP LAB 3

Question 1

Liquid or gel with nutrients that support microbial or cell growth.

Answer 1

Culture medium (growth medium)

Question 2

Based on physical state, distribution, composition, and function

Answer 2

Classification of culture media

Question 3

Medium without solidifying agent (e.g., Nutrient Broth, Mueller-Hinton Broth, Brain Heart Infusion Broth).

Answer 3

Liquid/Broth

Question 4

Contains 0.5–1% agar; used in motility/biochemical tests (e.g., SIM).

Answer 4

Semi-solid

Question 5

Contains 2–3% agar; provides surface for isolation (e.g., Blood Agar Plate, MacConkey Plate).

Answer 5

Solid

Question 6

Medium in tubes (butt, slant, liquid).

Answer 6

Tubed

Question 7

Agar solidified at an angle in test tubes.

Answer 7

Slant

Question 8

Tube containing both deep butt and slanted surface.

Answer 8

Butt and Slant

Question 9

Solid medium in Petri dishes.

Answer 9

Plated

Question 10

Exact, pure chemical composition is known.

Answer 10

Chemically-defined (synthetic)

Question 11

Contains natural extracts like yeast, meat, or peptones; composition varies per batch.

Answer 11

Complex (non-synthetic, natural)

Question 12

Support general bacterial growth; non-selective (e.g., Nutrient Agar, Plate Count Agar, Trypticase Soy Agar).

Answer 12

Nutrient Media

Question 13

Standard medium for total viable bacterial count.

Answer 13

Plate Count Agar (PCA)

Question 14

General-purpose medium for non-fastidious organisms.

Answer 14

Nutrient Agar (NA)

Question 15

Versatile medium for culture storage, isolation, and enumeration.

Answer 15

Trypticase Soy Agar (TSA)

Question 16

Promote growth of desired microbes while inhibiting others.

Answer 16

Selective Media

Question 17

Selective for coliforms; E. coli shows metallic green sheen.

Answer 17

Eosin Methylene Blue (EMB)

Question 18

Low pH medium for fungi and acid-tolerant microbes.

Answer 18

Yeast and Mold (YM)

Question 19

Selective for Gram-negative bacilli; differentiates lactose fermenters.

Answer 19

MacConkey Agar

Question 20

Selective for Staphylococci (high NaCl); differentiates mannitol fermenters.

Answer 20

Mannitol Salt Agar (MSA)

Question 21

Distinguish microbes by visible biochemical changes.

Answer 21

Differential Media

Question 22

Differentiates lactose fermenters.

Answer 22

EMB

Question 23

Differentiates Gram-negative lactose fermenters.

Answer 23

MacConkey Agar

Question 24

Differentiates mannitol-fermenting staphylococci.

Answer 24

MSA

Question 25

Detects hemolysis (α, β, γ).

Answer 25

Blood Agar Plate (BAP)

Question 26

Tests sugar fermentation and H₂S production.

Answer 26

Triple Sugar Iron (TSI) Slant

Question 27

Contain extra nutrients for fastidious organisms.

Answer 27

Enriched Media

Question 28

Nutrient agar enriched with blood.

Answer 28

Blood Agar Plate (BAP)

Question 29

Heat-treated blood medium (brown color).

Answer 29

Chocolate Agar

Question 30

Support growth of particular organisms.

Answer 30

Specific Media

Question 31

For Mycobacterium tuberculosis.

Answer 31

Lowenstein Jensen

Question 32

For Neisseria gonorrhoeae; contains antibiotics (vancomycin, polymyxin/colistin, nystatin).

Answer 32

Modified Thayer-Martin (VPN/VCN)

Question 33

Remove oxygen to allow growth of obligate anaerobes.

Answer 33

Reducing Media (Anaerobic Media)

Question 34

Common reducing medium.

Answer 34

Thioglycollate broth

Question 35

Example of Nutrient Media

Answer 35

Plate Count Agar Nutrient Agar Trypticase Soy Agar

Question 36

Composition of Nutrient Agar (m/v)

Answer 36

0.5% Peptone 0.3% Beef Extract 1.5% Agar 0.5% NaCl pH adjusted to neutral (6.8) at 25ºC

Question 37

Composition of PCA

Answer 37

0.5% Peptone 0.25% Yeast Extract 0.1% Glucose 1.5% Agar pH adjusted to neutral at 25ºC

Question 38

Composition of TSA

Answer 38

1.5% Tryptone 0.5% Soytone – enzymatic digest of soybean 0.5% Sodium Chloride 1.5% Agar

Question 39

Example of Selective Media

Answer 39

Eosin Methylene Blue (EMB) Sabouraud’s dextrose agar: Yeast and Molds (YM) MacConkey Agar Mannitol Salt Agar (MSA)

Question 40

Composition of EMB

Answer 40

Lactose Dipotassium Phosphate Eosin Y (Dye) Methylene Blue (Dye) Bile salt Agar

Question 41

Composition of YM

Answer 41

Malt Extract Yeast Extract Peptone Agar

Question 42

COmposition of MacConkey AGar

Answer 42

1.7% Peptone 1.3% Agar 1% Lactose 0.3% Proteose peptone 0.15% Bile salt 0.5% Sodium chloride Neutral red Crystal Violet- dye, inh. Also g(+) Water ; adjust pH to 7.1

Question 43

Inhibit g(+) bacteria

Answer 43

Bile Salt

Question 44

stains lactose fermenter microbes

Answer 44

Neutral Red

Question 45

dye, inh. Also g(+) The crystal violet inhibits growth of gram-positive organisms which allows for the isolation of gram-negative bacteria.

Answer 45

Crystal Violet

Question 46

Composition of MSA

Answer 46

0.5% Enzymatic digest of casein 0.5% Enzymatic digest of animal tissue 0.1% Beef Extract 1% D-mannitol 7.5% NaCl Phenol Red 1.5% Agar

Question 47

Example of Differential Media

Answer 47

Eosin Methylene Blue (EMB): MacConkey Agar Mannitol Salt Agar (MSA) Blood Agar Plate (BAP)