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Bt crops – some background

One of the most widespread genetic modifications of crops is the addition of a Bt gene, so here’s some background on what it is and what it does.

A bacteria found in soil, Bacillus thuringiensis, produces proteins that are toxic to certain insects, and so has been used as a ‘microbial insecticide’ for well over 50 years.

More recently, crops including cotton, potato and corn have been modified to contain the gene for an inactive form of the Bt toxin. The plant itself is therefore producing the toxin which naturally occurs in bacteria. The Bt toxin becomes active in the gut of insects, which is an acidic environment with specific enzymes. Continue reading