1. Use of microorganisms in food production

2. Bacteria is used to make yoghurt!
Milk is heated with milk protein and sugar
Heat kills bacteria
Different bacteria added
Bacteria ingest sugar (lactose) and ferment it into lactic acid (pH 4-5)
Acid makes the milk thick and sour (it curdles)

3. Bacteria is used to make cheese!
Milk is heated
Bacteria is added and ingest sugar (lactose) and ferment it into lactic acid (pH 4-5)
Acid splits milk into curds and whey
Rennet added to help curds solidify – cheese!