Micro organisms and their applications

Question 1

What is the aseptic technique?

Answer 1

prevents microbes from the air contaminating the culture or microbes from the culture contaminating the air.

Question 2

What is agar jelly?

Answer 2

a growth medium

Question 3

What is the first step in the aseptic technique?

Answer 3

Place the inoculating loop (metal) into a Bunsen burner flame

Question 4

2nd step?

Answer 4

Dip inoculating loop into sample being grown/tested

Question 5

3rd?

Answer 5

Streaking method, lightly drawing lines in the agar jelly for bacteria/fungus to grow

Question 6

4th?

Answer 6

Lid is placed on petridish and 4 pieces of tape are placed on the dish to secure lid. This is done to prevent contamination.

Question 7

5th?

Answer 7

To grow culture the bacteria is stored for 24-48hrs at 25*C

Question 8

6th?

Answer 8

Once finished agar petridishes must be sterilised.

Question 9

How can you slow bacteria growth?

Answer 9

-refrigerate (typically between 3-5*C)
-freezing stops growth but doesn’t kill bacteria

Question 10

What do antibiotics do?

Answer 10

Kill bacteria

Question 11

What is the fungus for penicillin?

Answer 11

Penicillium

Question 12

What are the three steps to test bacteria against antibiotics?

Answer 12

1. Sample taken including bacteria causing infection
2. Bacteria is grown in a lab on an agar plate for 24-48hrs and 20-25*C
3. Antibiotics applied on diff areas of plate (more bacteria=least effective, no bacteria=most effective)

Question 13

What is the process of fermentation for the production of microbes?

Answer 13

1. Starter culture of penicillium is added to a culture medium containing nutrients in the fermenter
2. Fermenter allows fine control of air supply, temperature and pH to ensure optimum growth by fungus
3. Fungus grows and secretes antibiotics into culture medium
4. When incubation comes to an end the culture medium is filtered and the penicillin is extracted from the filtrate.