Topic 6- Microorganisms And Their Application

Question 1

What is an aseptic technique?

Answer 1

Prevents microbes from air contamination or vice versa

Question 2

State the method of investigating the presence of bacteria in milk using agar plates

Answer 2

1- sterilise petri dishes and agar
2- use an inoculating loop to transfer a sample of milk to the petri dish. The loop should be sterilised.
3- wipe to surface of the agar with the inoculating loop and secure the lid of the petri dish.
4- incubate the plates at 25 degrees. After 48 hours examine the plates and count number of colonies.
5- record and repeat experiment with different milk samples
6- sterilise the plates again

Question 3

What is penicillin made from and who discovered it?

Answer 3

The fungus penicillium by Alexander Fleming

Question 4

State the process of fermenting penicillium to make penicilin

Answer 4

1- starter culture of penicillium is added to a culture medium containing nutrients in a fermenter.
2-The fermenter allows fine control of the air supply, temperature and pH to ensure optimal growth by the fungus
3-The fungus grows and secretes the antibiotic into the culture medium
4-when the information comes to an end the culture medium is filtered and the penicillin is extracted from the filtrate

Question 5

What are three uses of using microbes in food production?

Answer 5

Bread
Cheese
Yoghurt

Question 6

What are the advantages of using microbes for food production?

Answer 6

Rapid and contained growth
A predictable product is made under controlled conditions
Waste materials and other processes may be used as a food source for the Microorganisms

Question 7

What other environmental uses of microbes?

Answer 7

Digest and all the foliage drop by trees in woods
Break down some plastics
Cleaning up pollution (oil)
Production of biofuels