6.4.7: Microorganism cultures

Question 1

What does a growth medium need to provide for a microorganism to grow?

Answer 1

• Carbon compounds for respiration.

- Source of nitrogen for protein synthesis.

Question 2

What are the two types pf growth medium used in labs?

Answer 2

• Broth (liquid)

- Agar (set, jelly-like)

Question 3

What does agar contain?

Answer 3

• Salt and water
• yeast extract
• Peptones
• Glucose or blood

Question 4

Why are aseptic techniques used?

Answer 4

-To prevent the likelihood of contamination of the growth medium with unwanted bacteria or fungi.

Question 5

What are some aseptic techniques?

Answer 5

• Wash hands
• Disinfect area
• Bunsen burner (creates an area around it of sterile air)
• Flame bottle.
• Open petri dish only slightly.
• Glassware passed through flame.

Question 6

What are the three steps for growing microorganisms on agar plates?

Answer 6

1. Sterilisation
2. inoculation
3. Incubation

Question 7

1. sterilisation

Answer 7

Nutrient agar and equipment heated in autoclave for 15 mins.

Question 8

2. Inoculation

Answer 8

Introducing microorganism to sterile medium
-Streaking
-Seeding
spreading

Question 9

3 .Incubation

Answer 9

• Labelled and taped
• placed in a warm environment (incubator)
• Upside down, prevents drops of condensation on agar.
• examine after 24-36 hours