Microbes in Human Welfare
Microbes in industry
Name microbes and their industrial products.
In industry, microbes are grown on a large scale in huge vessels called fermentors to make useful products.
Drinks. Brewer's yeast (Saccharomyces cerevisiae) ferments malted cereals and fruit juices to produce ethanol. Different raw materials and processing give different drinks. Wine and beer are made without distillation; whisky, brandy and rum are made by distilling the fermented broth, which makes them much stronger.
Antibiotics are chemicals made by some microbes that kill or stop the growth of disease-causing microbes. The first, penicillin, was discovered by Alexander Fleming. Working with Staphylococcus bacteria, he noticed that a mould growing on one of his culture plates had stopped the bacteria growing around it. The mould was Penicillium notatum. Later, Ernest Chain and Howard Florey showed its full value as a medicine. All three shared the Nobel Prize in 1945. Penicillin was used widely to treat wounded soldiers in World War II. Antibiotics have since greatly reduced deaths from diseases such as plague, whooping cough, diphtheria and leprosy.
Chemicals, enzymes and other bioactive molecules. Learn them in pairs, microbe and product:
| Product | Microbe | Use |
|---|---|---|
| Citric acid | Fungus Aspergillus niger | Food and drinks |
| Acetic acid (vinegar) | Bacterium Acetobacter aceti | Food |
| Butyric acid | Bacterium Clostridium butylicum | Industry |
| Lactic acid | Bacterium Lactobacillus | Food |
| Lipases | Microbes | Detergents: remove oily stains from laundry |
| Pectinases and proteases | Microbes | Clarify bottled fruit juices |
| Streptokinase | Bacterium Streptococcus, modified genetically | A 'clot buster': dissolves clots in the blood vessels of heart-attack patients |
| Cyclosporin A | Fungus Trichoderma polysporum | Suppresses the immune system in organ-transplant patients |
| Statins | Yeast Monascus purpureus | Lower blood cholesterol, by blocking the enzyme that makes it |
This is why bottled fruit juices are clearer than home-made ones: enzymes have broken down the material that makes juice cloudy.
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