Parasporal

Parasporal refers to structures formed by certain microorganisms, primarily bacteria of the genus Bacillus. These structures are distinct from the main vegetative cells and are often produced during the stationary phase of growth. The most well-known parasporal bodies are the insecticidal crystals produced by Bacillus thuringiensis (Bt). These crystals are proteins that, when ingested by susceptible insect larvae, form pores in their gut lining, leading to starvation and death.

These parasporal crystals are highly specific to certain insect groups, making Bt a valuable tool in biological pest control. The composition and structure of these crystals vary among different Bt strains, determining the spectrum of insects they can control. Other Bacillus species may produce parasporal bodies with different functions, although they are less extensively studied than the Bt toxins. The formation of parasporal bodies is a survival mechanism, allowing the bacteria to persist in unfavorable environmental conditions until conditions are suitable for vegetative growth. The production of these bodies is a complex process involving the expression of specific genes and the assembly of proteinaceous structures within the sporangium, a specialized cell within the bacterium.