Back to: MICROBIOLOGY 400 LEVEL
Welcome to class!
Hello my genius learner! It’s such a delight to have you in class today. You’ve been learning so well, and today’s topic will feel like home—literally. We’re talking about Microbial Roles in Bread, Yoghurt, Cheese, and Alcohol. These are foods and drinks you probably enjoy or see around often, right? Well, did you know that tiny living organisms—microbes—are behind their production? Let’s uncover how these microbes work their magic and make our food tastier, healthier, and more valuable!
Microbial Roles In Bread, Yogurt, Cheese, Alcohol
Bread
When you think of fresh, soft, fluffy bread, think of yeast, especially Saccharomyces cerevisiae.
How it works: Yeast feeds on the sugar in the flour dough and releases carbon dioxide (CO₂). This gas forms bubbles, which make the dough rise and become fluffy.
Why it matters: Without yeast, bread would be flat and hard. This process is called fermentation.
Nigerian example: Most Agege bread bakers rely on active yeast to achieve that soft, stretchy texture we all love.
Yoghurt
Yoghurt is made from milk fermented by bacteria—mainly Lactobacillus bulgaricus and Streptococcus thermophilus.
How it works: These bacteria convert milk sugar (lactose) into lactic acid. This acid thickens the milk and gives yoghurt its sour taste.
Benefits: It helps in digestion and improves gut health.
Local touch: Nigerian yoghurt brands in supermarkets use this method to produce thick, creamy yoghurt in flavours like vanilla and strawberry.
Cheese
Cheese also begins with milk, but it involves more detailed bacterial action and sometimes moulds.
Microbes involved: Lactic acid bacteria like Lactococcus lactis start the fermentation, then other organisms like Penicillium (a fungus) may help in flavouring (especially in blue cheeses).
How it works: The bacteria ferment the milk sugar into lactic acid. An enzyme called rennet helps to curdle the milk, separating it into solid curds (cheese) and liquid whey.
Nigerian reality: While not as common as yoghurt, local cheesemakers, especially in northern Nigeria, use similar principles to make wara (soft local cheese).
Alcohol
The production of alcoholic drinks such as palm wine, beer, or wine depends heavily on yeasts, especially Saccharomyces cerevisiae.
How it works: Yeast ferments sugars from fruits or grains into alcohol and carbon dioxide.
Local examples:
Palm wine is naturally fermented using wild yeasts found in the sap.
Burukutu and Pito, traditional drinks in northern and middle-belt Nigeria, are also made through microbial fermentation using sorghum or millet.
Why Is This Important?
Microbes help preserve food, add nutrients, improve taste, and reduce waste. Instead of throwing away excess milk, for example, it can be turned into yoghurt or cheese. Also, fermentation improves the shelf life of food products, which is very important in Nigeria’s hot climate.
Summary
- Yeasts help bread rise by producing carbon dioxide from sugar.
- Bacteria like Lactobacillus and Streptococcus convert milk into yoghurt through lactic acid fermentation.
- Cheese is made using bacteria and enzymes that curdle milk, sometimes with moulds for flavour.
- Alcoholic beverages are made by yeasts fermenting sugars into alcohol.
- These microbes play vital roles in preserving food, enhancing flavour, and supporting local industries.
Evaluation
- Name the microbe responsible for making bread rise.
- Which two bacteria are used in yoghurt production?
- Explain briefly how cheese is made from milk using microbes.
- Give two local Nigerian examples of fermented alcoholic drinks and their raw materials.
You’re not just learning about microbes—you’re learning how science touches your everyday life and culture. Keep shining, because Afrilearn is walking with you on this beautiful journey of discovery and greatness. On to the next class, champ!