A parasporal body is a specific structure found in certain bacteria, notably within some Bacillus species. It's characterized as a bipyramidal crystal that is formed by one or more proteins. These proteins typically have a size of approximately 135 kDa and are known for their toxicity to the larvae of lepidopterans (moths and butterflies).
Key Characteristics of Parasporal Bodies
| Feature | Description |
|---|---|
| Structure | Bipyramidal crystal |
| Composition | One or more similar proteins |
| Protein Size | Approximately 135 kDa |
| Function | Toxic to lepidopterous larvae |
| Occurrence | Found in some Bacillus species |
How Parasporal Bodies Work
- Toxicity: The proteins within the parasporal body are toxic when ingested by susceptible lepidopteran larvae.
- Mode of Action: These proteins, once consumed, typically disrupt the digestive system of the insect leading to paralysis and eventually death.
- Specificity: They exhibit a degree of specificity, generally being toxic to certain groups of insects.
Practical Implications
Parasporal bodies are utilized in the production of Bacillus thuringiensis (Bt) based insecticides. Bt is a biological pesticide which utilizes these proteins for control of specific insect pests.
- Environmentally Friendly: Bt insecticides are generally considered more environmentally friendly than many synthetic pesticides due to their specificity and natural origin.
- Crop Protection: They can be highly effective at controlling pests on crops, reducing the need for other more harmful types of insecticides.
Examples
- Bacillus thuringiensis is a prime example of a bacterium that produces parasporal bodies which are commercially exploited in biological pest control.
In summary, parasporal bodies are crystal-like structures made up of proteins that are toxic to insects, playing a key role in natural pest control strategies.
