Toxins of Bacillus thuringiensis

Japanese authors were the first to establish insect disease of bacterial origin, when discovering the pathogen of the epidemic disease of the silk worm (Ishida, 1901). Berliner (1911 1915) found that the same bacterium, which he called Bacillus 

In the course of its vegetative reproduction, the bacterium produces exoenzymes, with the aid of which exogenous nutrients are made available for assimilation. Principally the effect of certain phospholipases has been studied but, although their insecticidal effect has been established, experimental results do not permit an unequivocal elucidation of the natiue of the action (Heimpel, 19SS Kushner and Heimpel, 1957 Rogoff, 1966). 

Three exotoxins were isolated from the supernatant liquid of Bacillus thuringiensis cultures. Among these, -exotoxin has been investigated most extensively. Its structure has not yet been established, but it is probably a nucleotide containing adenosine monophosphate (Heimpel, 1967 McConnel and Richards, 1959 De Barjac and Dedonder, 1965 Benz, 1966 Sebesta and Horska, 1968 Rogoff, 1966 Farkas et al 1969). 

In the course of sporulation, protein crystals are formed by the side of the spores. The toxic effect of Bacillus thuringiensis can be traced back primarily to 5-endotoxin which constitutes these para-sporal formations. Endotoxin crystals consist of silicon-containing, nucleotide-free protein, which is a protomer of molecular weight 373 000, consisting of basic units of 25 000 molecular weight (Faust and Esters, 1966 Lecadet, 1965 Angus, 1956 Spencer, 1968 Akune et al 1971). 

Of the toxic substances of various types in Bacillus thuringiensis, the effect of 

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Due to this lack of analytical methods, bioassays are often the only viable method for residue analysis. A good example are the larvicidal toxins of Bacillus thuringiensis (BT). 

Vadlamudi, R. K. Ji, T. H. Bulla Jr., L. A. A specific binding protein from Manduca sexta for the insecticidal toxin of Bacillus thuringiensis subsp. berliner. J. Biol Chem. 1993 268, 12334-12340. 

Del Rincon-Castro, M.C., J. Barajas-Huerta, and J.E. Ibarra. 1999. Antagonism between CrylAcl and CytlAl toxins of Bacillus thuringiensis. Appl. Envir. Microbiol. 65 2049-2053. 

Zhang, X., M. Candas, N. Griko, R. Taussig, and L. Bulla, Jr. 2006. A mechanism of cell death involving an adenylyl cyclase/PKA signaling pathway is induced by the CrylAb toxin of Bacillus thuringiensis. Proc. Natl. Acad. Sci. (USA) 103 9897-9902. 

Li, J., Carroll, J., and Ellar, D., 1991. Cry.stal. structure of in.secticidal 5-endo-toxin from Bacillus thuringiensis at 2.5 A resolution. Nature 353 815-821. 

Cohen, S., Cahan, R., Ben-Dov, E., Nisnevitch, M., Zaritsky, A., and Michael, A.F. (2007) Specific targeting to murine myeloma cells of CytlAa toxin from Bacillus thuringiensis subsp. Israelensis. /. Biol. Chem. 10.1074/jbc.M703567200. 

The range of poisonous chemicals produced by bacteria is also large. Again, such compounds may also be used for beneficial purposes, for example, the insecticidal properties of Bacillus thuringiensis, due to a toxin, have been utilized in agriculture for some time. 

The varieties of Bacillus thuringiensis used commercially survive when injected into mice, and at least one of the purified insecticidal toxins is toxic to mice. Infections of humans have been extremely rare (two recognized cases) and no occurrences of human toxicosis have been reported. From studies involving deliberate ingestion by human subjects, it appears possible, but not likely, that the organism can cause gastroenteritis. Bacillus thuringiensis... 

The insecticidal activity of Bacillus thuringiensis and its toxin is considerably increased when combined with lecithin (381). 

Applications of immunoassay to pesticide chemistry have been described which address some difficult problems in analysis by classical methods. These include stereospecific analysis of optically active compounds such as pyrethroids (38), analysis of protein toxins from Bacillus thuringiensis (5,37), and compounds difficult to analyze by existing methods, such as diflubenzuron (35) and maleic hydrazide (15 also Harrison, R.O. Brimfield, A.A. Hunter, K.W.,Jr. Nelson, J.O. J. Agric. Food Chem. submitted). An example of the excellent specificity possible is seen in assays for parathion (10) and its active form paraoxon (3). Some immunoassays can be used directly for analysis without extensive sample extraction or cleanup, dramatically reducing the work needed in typical residue analysis. An example of this is given in Figures 2 and 3, comparing the direct ELISA analysis of molinate in rice paddy water to the extraction required before GC analysis. 

Mazier, M., Pannetier, C., Tourneur, J., Jouanin, L. and Giband, M. (1997). The expression of Bacillus thuringiensis toxin genes in plant cells. Biotechnol. Ann. Rev. 3, 313-347. 

Williams, S., Friedrich, L., Dincher, S., Carozzi, N., Kessmann, H., Ward, E. and Ryals, J. (1993). Chemical regulation of Bacillus thuringiensis delta-endo-toxin expression in transgenic plants. Bio/Technology 7,194-200. 

Noteborn, H.P.J.M., Kuiper, H.A. and Jones, D.D. (1994). Safety assessment strategies for genetically modified plant products A case study of Bacillus thuringiensis-toxin tomato. In Proc. 3rd Int. Symp on The Biosafety Results of Field Tests of Genetically Modified Plants and Organisms (Young, A.L. and Economidis, 1., Eds). USD A, Monterey, USA, pp. 199-207. 

Malone, L.A., Burgess, E.P.J. and Stefanovic, D. (1999). Effects of a Bacillus thuringiensis toxin, two Bacillus thuringiensis biopesticide formulations, and a soybean trypsin inhibitor on honey bee (Apis mellifera L.) survival and food consumption. Apidologie 30,465 73. 

CjjHsjNjO, , Mr 701.49, [a]g +30.9° (HjO), a thermostable nucleotide toxin from cultures of Bacillus thuringiensis van gelechiae. In contrast to the Thurin-giensis endotoxins (proteins), T. are only formed and excreted by certain serotypes. The insecticidal and cytotoxic activity is based on the inhibition of DNA-de-pendent RNA polymerase. 

Ravoahangimalala, O. Charles, J.-F. In vitro binding of Bacillus thuringiensis var. israelensis individual toxins to midgut cells of Anopheles gflffib/ne larvae (Diptera Culicidae). FEBSLetl 1995 362,111-115. 

Yamagiwa, M., Kamauchi, S. Ogawa, R. Esaki, M. Otake, K. Amachi, T. Komano, T. Sakai, H. Binding properties of Bacillus thuringiensis Cry4A toxin to the apical microvilli of larval midgut of Culex pipiens. Biosci. Biotechnol. Biochem. 2001 65,2419-2427. 

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