Microorganisms & Biotechnology
This lesson covers:
- What biotechnology is
- Examples of industrial processes involving microorganisms
- The advantages and disadvantages of using microorganisms in biotechnology
What is biotechnology?
Biotechnology uses living organisms or their components, such as enzymes, to synthesise, breakdown, or transform materials for human use.
Microorganisms (microbes), including bacteria, yeasts, moulds, and algae, are often used in these processes, with enzymes as essential biological catalysts.
Major applications of microbes in biotechnology:
- Brewing - Yeasts, particularly Saccharomyces cerevisiae, ferment sugars anaerobically to produce ethanol and carbon dioxide to make alcoholic drinks like wine and beer.
- Baking - The carbon dioxide produced by yeast during sugar fermentation makes bread dough rise.
- Cheese making - Chymosin, an enzyme from genetically modified yeast, coagulates milk into curds, while bacteria and moulds contribute to acidification, thickening, and flavour.
- Yoghurt - Certain bacteria ferment lactose, a sugar in milk, into lactic acid, which sours and solidifies milk into yoghurt.
- Medicines - Bioengineered fungi and bacteria produce drugs, like the antibiotic penicillin and insulin for diabetes treatment.
- Bioremediation - Microbes can speed up the degradation of pollutants like oil spills.
Making penicillin
Penicillium chrysogenum is a fungus that synthesises penicillin as a growth by-product.
It requires the following conditions:
- Small fermenters with constant stirring to ensure high oxygen levels.
- A nutrient-rich medium for optimal growth.
- A buffer to keep the pH stable at around 6.5.
- A constant temperature of about 25–27°C for ideal fungal activity.
Penicillin can then be extracted and purified for medical use.
Bioremediation
Bioremediation uses microbes to decompose pollutants and contaminants in soil or water, making it a critical environmental restoration technique.
There are two main approaches to bioremediation:
- Use natural organisms - This uses microbes' natural ability to digest organic materials, such as in sewage or oil spills, along with the addition of certain nutrients.
- Develop genetically modified organisms for specific contaminants - This uses bacteria to break down or accumulate specific pollutants like mercury.
Advantages and disadvantages of using microorganisms in biotechnology
The use of microorganisms in biotechnology offers several benefits and drawbacks.
| Advantages | Disadvantages |
|---|---|
| Cost-effective cultivation and mass production lead to lower consumer prices. | Sterile conditions are necessary, which can increase operational costs. |
| No ethical issues related to animal welfare. | Risk of contamination by unwanted microbes. |
| Rapid reproduction rates enable fast, large-scale production. | Potential toxin production by some microbes necessitates removal processes. |
| Simple and versatile nutrient requirements, including the ability to use waste materials, which can lower costs. | Separation of microorganisms from the nutrient broth is required for food production. |
| High protein and low fat content make them an efficient food source, offering a sustainable alternative to meat. | Differences in texture and taste from traditional food sources may require the addition of flavour enhancers. |
| Genetic modification can enhance nutrient profiles or optimise production. | Social concerns about genetically modified foods or microbes grown on waste products. |
| Independent of weather or breeding cycles, allowing for year-round production regardless of climate. |