Question

Which bacteria is used as biopesticide first on the commercial scale in the world
A. Bacillus thuringiensis
B. E. coli
C. Pseudomonas aeruginosa
D. Agrobacterium tumefaciens

Answer 1

As we all know that Biopesticides are a certain type of pesticides which are derived from plants, animals, bacteria and various minerals. These microorganisms are genetically modified and used to control the pests or insects harming plants.

Complete answer:
As we all know that Biopesticides are a certain type of pesticides which are derived from plants, animals, bacteria and various minerals. These are basically divided into three major classes which are biochemical pesticides, microbial pesticides and plant incorporated protectants.
We will talk about Microbial biopesticides here, these pesticides consist of microorganisms like bacterium, fungus, virus and protozoans as the active ingredient. The most widely used microbial biopesticide is the Bacillus thuringiensis (Bt), it has been produced to provide resistance to the insects.
It is a genetically modified organism and each strain of this bacterium produces a different mix of protein which are in inactive forms and exist as inactive protoxin. Once the insect digest this protein, it is converted into an active form of toxin and due to the alkaline pH of the gut of the insect it gets solubilised into crystals.
The activated toxin binds to the surface of midgut epithelial cells of the insect thereby creating pores that causes swelling and lysis of the cell which eventually leads to death of the insect.
B. thuringiensis was used as a pesticide for the first time on commercial basis and was used to produce Bt cotton which was a cotton bollworm resistant variety of cotton.

Hence the correct answer is (A).

Note: Some advantages of biopesticides:
The biopesticides control the pests growth as well as it produce a very little amount of toxic residue which are of minimal risk to human health.
It is cheaper than other chemical pesticides. It is also biodegradable and generally is effective in small quantities hence avoiding environmental pollution problems.