Uses of Microorganisms - EP - 3
3 Minutes
Uses of microorganisms in daily life for kids: learn how yeast, curd bacteria, and gut microbes help us. An English science lesson.
- How yeast ferments dough to make soft bread
- How Lactobacillus bacteria turn warm milk into curd
- How gut bacteria like E. coli aid digestion and make vitamins
What this lesson teaches
Microorganisms play vital roles in everyday life, helping to prepare common foods and keeping the human digestive system healthy. Microscopic organisms such as fungi, algae, and bacteria carry out fermentation to create staple foods like bread and curd, while gut microbes aid digestion and supply essential vitamins.
How yeast and algae are used in bread making
Making bread requires maida flour, butter, milk, sugar, and yeast powder, which is a type of fungus that is first activated by feeding on the sugar in warm milk. After the activated yeast mixture is kneaded thoroughly with the flour and butter into a firm dough, it is left undisturbed so the yeast can begin fermentation. During fermentation, the yeast breaks down the sugar molecules in the dough into smaller parts and releases carbon dioxide gas, which makes the dough rise and bake into soft bread. Along with yeast, an algae called Chlorella is often added when making bread or cake to enrich the food with extra vitamins, proteins, and essential nutrients.
How bacteria convert milk into curd
Liquid milk is turned into thick curd by simply mixing a small amount of old curd into warm milk. The old curd contains beneficial bacteria called Lactobacillus, which carry out fermentation by breaking down lactose, the sugar molecule in milk. This fermentation process converts lactose into lactic acid, which then reacts chemically with the casein protein found in milk. That reaction changes the milk protein into a fibrous texture, causing the liquid milk to set into thick curd after resting for a while.
Helpful bacteria in the digestive system
- Lactobacillus acidophilus bacteria live naturally inside the human digestive tract, where they break down consumed food into smaller parts to support healthy digestion.
- Lactobacillus acidophilus also serves a protective function in the digestive system by actively fighting off harmful microorganisms that enter the body.
- Another group of bacteria called E. coli live in the stomach, where they perform the vital job of producing nutrients required by the body.
- These resident E. coli bacteria manufacture essential vitamins that humans need every day, specifically vitamin K and vitamin B complex.