Production of Biopesticides

Biopesticides use microbes like the bacterium Bacillus thuringiensis, or Bt, to control pests.

During sporulation, Bt produces insecticidal proteins known as Cry proteins, which crystallize alongside the spores.

These crystal proteins act as the primary active ingredient in Bt biopesticides.

Upon insect ingestion, these crystals dissolve in the gut, releasing toxins that kill the insect.

One method for Bt biopesticide production involves solid-state fermentation, where the bacterium is cultivated on nutrient-rich solids like rice bran.

At the start of this process, the substrate is moistened, inoculated with Bt spores, and then loaded into a packed-bed bioreactor.

Controlled temperature and aerobic conditions support the growth of Bt.

As nutrients become limited, the bacteria undergo stress-induced sporulation, during which crystal proteins are produced.

The crystals are purified into powders or granules for environmentally friendly field application.