Why microorganisms are ideal
Microorganisms are widely used in biotechnology for several biological reasons:
Rapid reproduction: Bacteria can divide by binary fission every 20-30 minutes under optimal conditions, producing large populations quickly. Yeast also reproduces rapidly by budding.
Simple nutritional needs: Most microorganisms can grow on simple, inexpensive nutrients, making large-scale production cost-effective. Many can use waste products from other industries as food sources.
Small size: Large numbers can be grown in relatively small fermenters, taking up less space than farming animals or growing crops.
Genetic modification: Bacteria can be genetically engineered to produce specific proteins (such as human insulin) by inserting genes from other organisms into their plasmids.
Types of microorganisms used
| Microorganism | Use in biotechnology |
|---|---|
| Bacteria (e.g. E. Coli, Lactobacillus) | Insulin production, yoghurt making, decomposition in sewage treatment |
| Yeast (Saccharomyces) | Bread making, beer and wine production, bioethanol |
| Fungi (Penicillium) | Antibiotic production (penicillin), cheese making |
Each microorganism has specific metabolic capabilities that make it suitable for particular biotechnological applications.
Aseptic technique
When working with microorganisms in biotechnology, aseptic technique is essential to prevent contamination. Contamination by unwanted microorganisms can compete with the desired organism, produce toxic substances, or spoil the product.
Aseptic techniques include sterilising equipment (autoclaving at 121 degrees C), using sterile media, working near a Bunsen flame to create updrafts that carry airborne microbes away, and sealing containers. In industrial fermenters, all inputs (air, nutrients) are sterilised before entering the vessel.