Bacillus Thuringiensis

 

History

Page history last edited by Julia 1 yr ago

 

 

HISTORY

 

 

Bacillus thuringiensis was first discovered in 1901 in Japan by Ishiwata and in 1911 in Germany by Ernst Berliner. Many years later, it would be developed into a popular pesticide for crops.

 

Scientists at first thought that Bacillus thuringiensis was complex enough in structure and information that little to no insect resistence would appear. After several years of research, including many experiments and trials, however, it's been proven that this is not quite true. Six insects have already been thought to resist the common strands of Bacillus Thuriengsis: including the Indian meal moth, the first to successfully develop immunity to the bacterium.

 

Of course, the more B.t. is used as pesticide with crops, the faster strains are resisted by insects. In this way, of course, the bacterium is now being used beneficially, and with more care.

 

B.t. is toxic, but only in doses strong enough to harm organisms with significantly less complex systems: specifically, insects. In humans, the most ridiculously strong doeses of the endotoxin causes some irritation in the eyes and nausea. There is no significant evidence to support the theory that B.t. could be especially hazardous to the human population.

 

 

Specifics:

 

The Japanese biologist Ishiwatari was investigating the cause for sudden-collapse disease in a population of silk worms when he first isolated bacillus thuriengis as the catalyst. This was in 1901.

 

In 1911, German scientist Ernst Berliner discovered b.t. after examining a Mediterranean flour moth that died from its effects. He named it bacillus thuringiensis, after the town of Thuringia where this dead moth was found. Furthermore, in 1915, Berliner discovered that the bacterium produced crystals, but its activities weren't discovered until later.

 

Around the 1920s, b.t. began to be used as a pesticide in areas of the world. France, specifically, started some of the first commercialized b.t. pesticide products. Other b.t. products were marketed, but, at the time, there were many limitations to its uses: such as poor effects in accordance to weather, UV rays, the specific types of insects only effected, and the product's penetration into the ground. It wasn't until 1956, when researchers Hannay, Fitz-James, and Angus discovered that the protein crystals and their substances were the cause of insectal death, that b.t. as a pesticide shot off into marketing and use on farms.

 

In the US, b.t. wasn't specifically used as a pesticide until 1958. In 1961, it was registered by the EPA as an official pesticide.

 

Around 1977, only thirteen strains of b.t. were currently used and developed on plantations. During the span of the 1980's, however, new strains were being discovered, including b.t. that finally effected flies and beetles. In latter years of the decade, b.t. was a serious factor in farmlands, as most other synthetic pesticides had become fully immune to resisting insect populations. B.t. was also organic and less fussy than some of the other products developed.

 

Since now, thousands of bacillus thuringiensis strains have been produced in the world. Gradually, the idea became to engineer plants with b.t. properties. In 1995, the first genetically altered plant with the protein crystal-producing methods of b.t. was created and registered with the EPA.

 

Today, GM (genetically modified) plants with b.t. properties are being used consistently, including  potato and cotton crops.

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