Using Microbes

Question 1

How is beer produced using microbes?

Answer 1

• Yeast is used and added to glucose.
• The yeast uses a process called anaerobic respiration to ferment.
• The glucose is converted into ethanol (alcohol) and carbon dioxide.

Question 2

How is yoghurt produced using microbes?

Answer 2

• Milk is pasteurised at 85˚C-95˚C (to kill any harmful bacteria).
• Lactobaccilus is added after the milk is cooled to around 40˚C (to make sure the bacteria doesn’t die when it is added).
• The mixture is kept at 40˚C (so that the enzymes work best and as much bacteria can reproduce into lactic acid - maximise the yield).
• If fruit is added to the yoghurt, it has been sterlised beforehand (to kill ay bacteria so that it is not harmful to humans eating the yoghurt).