Bacillus thuringiensis is a Gram-positive, soil dwelling bacterium of the genus Bacillus. Additionally, B. thuringiensis also occurs naturally in the caterpillars of some moths and butterflies, as well as on the surface of plants.^[1] Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... Classes Bacilli Clostridia Mollicutes The Firmicutes are a division of bacteria, most of which have Gram-positive stains. ... Orders Bacillales Lactobacillales The term bacilli (singular bacillus) is used to refer to any rod-shaped bacteria. ... Families Alicyclobacillaceae Bacillaceae Caryophanaceae Listeriaceae Paenibacillaceae Planococcaceae Sporolactobacillaceae Thermoactinomycetaceae The Bacillales are an order of Gram-positive bacteria, placed within the Firmicutes. ... Wikipedia does not have an article with this exact name. ... Species Bacillus anthracis Bacillus cereus Bacillus coagulans Bacillus natto Bacillus subtilis Bacillus thuringiensis etc. ... In biology, binomial nomenclature is the formal method of naming species. ... Gram-positive bacteria are those that are stained dark blue or violet by gram staining, in contrast to gram-negative bacteria, which are not affected by the stain. ... Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... In biology, a genus (plural genera) is a taxonomic grouping. ... Species Bacillus anthracis Bacillus cereus Bacillus coagulans Bacillus natto Bacillus subtilis Bacillus thuringiensis etc. ... The striking caterpillar of the Emperor Gum Moth This article is about insect larva. ... A moth is an insect closely related to the butterfly. ... Families Superfamily Hesperioidea: Hesperiidae Superfamily Papilionoidea: Papilionidae Pieridae Nymphalidae Lycaenidae Riodinidae A butterfly is an insect of the Order Lepidoptera, and belongs to one of the superfamilies Hesperioidea (the skippers) or Papilionoidea (all other butterflies). ...

B. thuringiensis was discovered 1901 in Japan and 1911 in Germany by Ernst Berliner, who discovered a disease called Schlafsucht in flour moth caterpillars. B. thuringiensis is closely related to B. cereus, a soil bacterium, and B. anthracis, the cause of anthrax: the three organisms only differ in their plasmids. Like other members of the genus, all three are aerobes capable of producing endospores.^[1] 1901 (MCMI) was a common year starting on Tuesday (see link for calendar) of the Gregorian calendar (or a common year starting on Wednesday of the 13-day-slower Julian calendar). ... 1911 (MCMXI) was a common year starting on Sunday (click on link for calendar). ... Binomial name Bacillus cereus Frankland & Frankland, 1887 Bacillus cereus is a gram-positive bacterium that causes foodborne illness, and is particularly noted for doing so in rice. ... Binomial name Bacillus anthracis Cohn 1872 Bacillus anthracis is a Gram-positive, facultatively anaerobic, rod-shaped bacterium of the genus Bacillus. ... Figure 1: Schematic drawing of a bacterium with plasmids enclosed. ... An aerobic organism or aerobe is an organism that has an oxygen based metabolism. ... Endospore forms An endospore is any spore that is produced within an organism (usually a bacterium). ...

Use in pest control

Spores of B. thuringiensis, as well as proteins created by the organism are used as Lepidopteran-specific insecticides under trade names such as Dipel and Thuricide. Because of their specificity, these pesticides are regarded as Environmentally friendly, with little or no effect on humans, wildlife, pollinators, and most other beneficial insects. A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Super Families Butterflies Hesperioidea Papilionoidea Moths Micropterigoidea Heterobathmioidea Eriocranioidea Acanthopteroctetoidea Lophocoronoidea Neopseustoidea Mnesarchaeoidea Hepialoidea Nepticuloidea Incurvarioidea Palaephatoidea Tischeriodea Simaethistoidea Tineoidea Gracillarioidea Yponomeutoidea Gelechioidea Zygaenoidea Sesioidea Cossoidea Tortricoidea Choreutoida Urodoidea Galacticoidea Schreckensteinioidea Epermenioidea Pterophoroidea Aluctoidea Immoidea Axioidea Hyblaeoidea Thyridoidea Whalleyanoidea Pyraloidea Mimallonoidea Lasiocampoidea Geometroidea Drepanoidea Bombycoidea Calliduloidae Hedyloidea Noctuoidea Families About... An insecticide is a pesticide used against insects in all developmental forms. ... A cropduster spreading pesticide. ... The phrase environmentally friendly is used to refer to goods or services considered to inflict little harm on the environment. ... Trinomial name Homo sapiens sapiens Linnaeus, 1758 Humans, or human beings, are bipedal primates belonging to the mammalian species Homo sapiens (Latin for wise man or knowing man) under the family Hominidae (known as the great apes). ... Various species of deer are commonly seen wildlife across the Americas and Eurasia. ... A pollinator is the agent that moves pollen from the male anthers of a flower to the female stigma of a flower to accomplish fertilization or syngamy of the female gamete in the ovule of the flower by the male gamete from the pollen grain. ... For most people, when they think of insects, they think of pests such as mosquitoes or tomato worms. ...

The material is distributed, usually in a liquid spray on the leaves of affected plants, where the pesticide must be eaten to be effective. Previously it was thought that the protein crystals break down cells within the gut of the caterpillars. Recent research has disproven this theory, as the midgut bacteria in the insects are required for the insecticidal activity (http://www.pnas.org/cgi/reprint/0604865103), and the insects die sooner when intoxicated than when starved. The exact mechanism of the protein crystal toxicity is still unknown. The striking caterpillar of the Emperor Gum Moth This article is about insect larva. ...

Bacillus thuringiensis var israelensis, a strain of B. thuringiensis is widely used as a larvicide against mosquito larvae, where it is also considered an environmentally friendly technique of mosquito control. Bacillus thuringiensis subspecies israelensis, also known as Bti, is a biological control agent for larval mosquitoes. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Genera See text. ... A larva (Latin; plural larvae) is a juvenile form of animal with indirect development, undergoing metamorphosis (for example, insects or amphibians). ... Mosquito control is the issue regarding overpopulation of mosquitoes in various parts of the world. ...

Genetic engineering for pest control

Bacillus thuringiensis, or Bt, is an endospore forming, soil-dwelling bacterium. The bacteria forms protein crystal δ-endotoxins from Cry genes. These toxins have effects on Leidoptera (Caterpillars) and Coleoptera (Beetles) species. These toxins are used as biological control in organic farming and as transgenes in GM crops.

Usage

In 2000 more than 115,000 square kilometres of Bt transgenic crops were grown, constituting 19% of the worlds GM crops. There is potential for Bt GM crops to take up 33% of the insecticide market. The current use of transgenic Bt crops reduces the number of chemical insecticide treatments by more than 7.7 million acres (31,000 km²) per year.

Advantages

Transgenic Bt crops have even distribution of the toxin throughout the plant. The treatment is constant unlike chemical spraying which creates many pauses.

Safety

Transgenic crops, including Bt crops, are safe for the farmers and for consumers. The toxin is insect specific and poses no danger to humans or other vertebrates.

Problems

The expression of the Bt gene can vary. For instance, if the temperature is not ideal this stress can lower the toxin production and make the plant more susceptible. Secondary pests are not controlled by Bt transgenic crops. Due to the constant exposure to the toxin an evolutionary selective pressure is created for resistant pests. There is also a hypothetical risk that for example, transgenic maize will crossbreed with wild grass variants, and that the Bt-gen will end up in a natural environment, retaining its toxicity. Transgenic maize (corn) has been deliberately genetically modified to have agronomically desirable traits. ...

Fighting Resistance

Non-Bt-Gm crop refuges could be created to allow some non-resistant insects to survive and maintain a susceptible population. Moderate expression of the transgene would also achieve the same end. Creating a mosaic GM crop expressing many different Bt toxins would have a greater chance of eliminating the entire pest population. ^[2] Another approach is to provide "refuges" of non-Bt crops, which is often required by legislation. The aim is to encourage a large population of pests so that any genes for resistance are greatly diluted. This appears to be successful.^[3]

References

1. ^ ^a b Madigan, Michael; Martinko, John (editors) (2005). Brock Biology of Microorganisms, 11th ed., Prentice Hall. ISBN 0-13-144329-1.
2. ^ Atkinson, H. Lecture: Engineering Resistance to Insects.
3. ^ Bt Cotton Script - Australian Broadcasting Corporation's Science Show See also Controlling pests in cotton crops