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efficacy and persistence of bacillus sphaericus, bacillus thuringiensis var. israelensis, and methoprene against culiseta incidens (diptera: culicidae) in tires.the efficacy and persistence of bacillus sphaericus (2362) was compared at three dosage rates in tires that continually contained cadavers of culiseta incidens (thomson) versus tires with all dead larvae removed. at treatment rates of 3.75 and 7.5 ppm, the continual presence of cadavers in the tire water resulted in higher mortality rates. at the 15 ppm treatment rate, mortality rates were similar in tires with or without cadavers. mortality rates increased in all tires 4-6 wk after treatment, s ...19901976658
effects of bacillus thuringiensis delta-endotoxin on the permeability of brush border membrane vesicles from tobacco hornworm (manduca sexta) midgut.1. the effect of two recombinant bacillus thuringiensis delta-endotoxins on brush border membrane vesicles of manduca sexta midgut was investigated using an in vitro assay system, based on ion-amino acid cotransport. 2. a cryia(b)-toxin provoked an increase in the permeability of the vesicles. 3. a cryib-toxin, not toxic to m. sexta larvae in vivo, had no effect in our assay. 4. in contrast to earlier reports, the increase in permeability was found to be neither selective for k+ nor specifically ...19901977553
the effect of bacillus thuringiensis israelensis [h-14] on emergence of mansonia mosquitos from natural breeding habitat.the measurement of the ultimate effects of the microbial insecticides on mosquito density is best obtained by assessment of adult populations. the main aims of this study are: (1) to assess the effect of bacillus thuringiensis israelensis (bti) fc skeetal and bactimos briquettes on the emergence rate of mansonia bonneae developed from the introduced first-instar stage larvae and (2) to measure the effect of these two formulations of insecticides on mansonia adult populations emerging from the na ...19901981631
larvicidal activity of chimeric bacillus thuringiensis protoxins.bacillus thuringiensis subspecies kurstaki (btk) and subspecies berliner (btb) both produce lepidopteran-specific larvicidal protoxins with different activities against the same insect species. toxic activity resides in the amino-terminal half of both protoxins, whereas the carboxy-terminal half of the molecules is not required for toxicity. the protoxins are 90% homologous, with a major cluster of differences in the amino-terminal half, and a 26 consecutive amino-acid insertion within the carbo ...19902082153
activation of a cryptic crystal protein gene of bacillus thuringiensis subspecies kurstaki by gene fusion and determination of the crystal protein insecticidal specificity.dna hybridization with the insecticidal crystal protein gene crylla (formerly crybl) of bacillus thuringiensis supspecies kurstaki has shown that subspecies kurstaki contains a crylla-related sequence in addition to the crylla gene (donovan et al., 1988a). we have cloned the crylla-related sequence and have determined that the sequence, which has been designated cryllb, is 89% identical to the crylla gene. recombinant b. thuringiensis cells harbouring the cloned cryllb gene produced very little ...19902089222
molecular characterization of immune inhibitor a, a secreted virulence protease from bacillus thuringiensis.the gene for the secreted neutral metalloprotease, immune inhibitor a (ina), from bacillus thuringiensis var. alesti has been cloned and sequenced. the deduced amino acid sequence has been confirmed by partial amino acid sequencing. the central part of the amino acid sequence showed similarity to the active site in thermolysin. southern and western blots show that ina-related sequences are common among other b. thuringiensis subspecies. in western blots, 17 out of 25 tested species gave a positi ...19902089225
[the choice of the optimal aeration conditions for the stab cultivation of bacillus thuringiensis h14 266/2-1].optimal conditions of aeration with depth regime of cultivation of bacillus thuringiensis h14 266/2-1, their effect on the output of biomass, endotoxin and activity of bacteria have been studied. the aeration conditions are optimized using the mathematical method of experiment planning. it is established that the air supply favours an increase of the bacillary biomass and insecticide activity for the whole cultivation period. in the first day of fermentation it is inexpedient to increase to rate ...19902097498
integrated use of planaria (dugesia dorotocephala) and bacillus thuringiensis var. israelensis against aedes taeniorhynchus: a laboratory bioassay.the effectiveness of integrating bacillus thuringiensis var. israelensis (b.t.i.) and the predatory planaria, dugesia dorotocephala against aedes taeniorhynchus was determined under controlled laboratory conditions. there was no significant effect (p greater than 0.05) of b.t.i. on d. dorotocephala either by direct association or through ingestion of b.t.i. dosed larvae. planaria, alone, and b.t.i. combined with planaria, both provided significant (p less than 0.05) reduction of ae. taeniorhynch ...19902098475
chemical management of forest pest epidemics: a case study.the management of insect epidemics in large tracts of forest is difficult given the climatic conditions encountered, the topography of the forested land, the nature of the forest, the types of chemical and/or biological insecticides registered for use, and the technologies available for insecticide application. since 1952, the province of new brunswick, canada, has been heavily involved in attempting to control an epidemic of the eastern spruce budworm (choristoneura fumiferana. clemens) that ha ...19902099793
effect of phospholipase c from bacillus cereus on the release of membrane-bound choline-o-acetyltransferase from rat hippocampal tissue.some of the enzyme choline-o-acetyltransferase (chat) associated with central cholinergic nerve terminals appears to be non-ionically associated with membranes. in the present study, we tested the possibility that some membrane-bound chat might be anchored to membranes by a phosphatidylinositol linkage by incubating rat hippocampal tissue with phospholipase c (plc) from bacillus cereus. the plc selectively augmented the release of chat; also, the glycosylphosphatidylinositol-plc inhibitor, zinc, ...19902106007
isolation and propagation of phages naturally associated with the aizawai variety of bacillus thuringiensis.this study describes the isolation of a phage, using mitomycin c and u.v. light, from each of four strains (hd67, hd130, hd228 and hd248) of bacillus thuringiensis h-serotype 7 (var. aizawai). it also describes the isolation of two indicator strains (12.13 and hd102) for these phages (phi hd67, phi hd130, phi hd228 and phi hd248) and the ideal conditions, using these indicator strains, for maximum phage production.19902107162
response of nuclear polyhedrosis virus-resistant spodoptera frugiperda larvae to other pathogens and to chemical insecticides.selection in the laboratory for spodoptera frugiperda (sf) resistant to nuclear polyhedrosis virus (npv) affected the susceptibility of the insect to certain other mortality agents, including a chemical insecticide. median lethal concentrations (lc50s) and associated statistics were compared for several mortality agents between colonies of npv-resistant and -susceptible (control) insects. compared to the susceptible insects, the npv-resistant insects were cross-resistant to the s. frugiperda gra ...19902108223
characterization of the cysteine residues and disulphide linkages in the protein crystal of bacillus thuringiensis.bacillus thuringiensis produces a 130-140 kda insecticidal protein in the form of a bipyramidal crystal. the protein in the crystals from the subspecies kurstaki hd-1 and entomocidus was found to contain 16-18 cysteine residues per molecule, present primarily in the disulphide form as cystine. evidence that all the cysteine residues form symmetrical interchain disulphide linkages in the protein crystal was obtained from the following results: (i) the disulphide diagonal procedure [brown & hartle ...19902110449
bacitracin-induced proteins in bacillus subtilis and bacillus thuringiensis and their relationship with resistance.bacitracin induced one protein (bacitracin-induced protein [bip]) in bacillus thuringiensis and two proteins (bip1 and bip2) in bacillus subtilis that were localized in the membrane. divalent cations acted as cofactors for induction in all three cases. growth was initially inhibited by the antibiotic, but following induction of proteins growth resumed. b. subtilis cells possessing bips were able to duplicate at a normal rate in the presence of bacitracin. the amount of b. subtilis bips diminishe ...19902113795
purification and characterization of bacillus thuringiensis var. tenebrionis insecticidal proteins produced in e. coli.native and single amino acid variants of the bacillus thuringiensis var. tenebrionis insecticidal proteins were expressed in escherichia coli, purified and examined for biological and biochemical properties. a novel, ph dependent, preferential precipitation method was implemented to purify escherichia coli produced bacillus thuringiensis var. tenebrionis proteins, which are active against colorado potato beetle (leptinotarsa decemlineata) larvae. cysteine residues of the native bacillus thuringi ...19902116794
plasmid-associated sensitivity of bacillus thuringiensis to uv light.spores and vegetative cells of bacillus thuringiensis were more sensitive to uv light than were spores or cells of plasmid-cured b. thuringiensis strains or of the closely related bacillus cereus. introduction of b. thuringiensis plasmids into b. cereus by cell mating increased the uv sensitivity of the cells and spores. protoxins encoded by one or more b. thuringiensis plasmids were not involved in spore sensitivity, since a b. thuringiensis strain conditional for protoxin accumulation was equa ...19902119568
evidence for a role of phosphatidylcholine-hydrolysing phospholipase c in the regulation of protein kinase c by ras and src oncogenes.the products of ras and src oncogenes are thought to be important components in pathways regulating cell proliferation and differentiation. in fibroblasts transformed by these oncogenes, increased diacylglycerol levels have been found which most probably arise from activation of the turnover of phosphatidylcholine. diacylglycerol is a key activator of protein kinase c whose role in cell growth and transformation has been proposed. we demonstrate here by using immunochemical techniques that trans ...19902123453
efficiency of transcriptional terminators in bacillus subtilis.to promote more efficient synthesis of heterologous gene products in a bacillus subtilis host, we have developed a system for rapidly testing the effect of a putative terminator on in vivo gene expression. terminator structures from the bacillus amyloliquefaciens amye gene, the bacillus licheniformis penp gene, the b. subtilis bgls gene, and the bacillus thuringiensis cry gene were subcloned and inserted into a vector in such a way as to disrupt expression of the cat-86 gene. comparisons are mad ...19902123811
mercury resistance determined by a self-transmissible plasmid in bacillus cereus 5.inducible mercuric reductase activity in bacillus cereus 5 was plasmid-encoded. plasmid analysis revealed three plasmids with molecular masses of 2.6, 5.2 and 130 mda. a mating system permitted transfer of the resistance determinant among strains of b. cereus and b. thuringiensis. transfer of mercury resistance from b. cereus 5 to b. cereus 569 and b. thuringiensis occurred during mixed culture incubation on agar surfaces. the 130-mda plasmid (pgb130) was responsible for transfer; frequencies ra ...19902127369
high temperature of development and selection of bacillus thuringiensis-supernatant-resistant females in a drosophila melanogaster oregon r strain.the supernatant of bacillus thuringiensis cultures contains a thermostable toxin: the beta exotoxin or thuringiensin, which in vivo acts as a preferential inhibitor of ribosomal rna synthesis. added to drosophila melanogaster culture medium, it induces, during the flies' development, a lethal effect that is, in our oregon r strain, greater for females than for males. the authors have previously shown that a diminution of the ribosomal dna amount increases the sensitivity to the lethal effect of ...19902128069
field evaluation of four biorational larvicide formulations against anopheles albimanus in honduras.four biorational larvicide formulations: teknar (b.t.i.), arosurf msf (monomolecular surface film), arosurf msf combined with teknar, and san-809-i ([s]-methoprene combined with b.t.i.), were evaluated against naturally occurring populations of the malaria vector mosquito anopheles albimanus wiedemann in honduras. all formulations reduced the mean number of larvae per sample area to 0 within 48 h after treatment, and gave significant (p less than 0.05) control when compared with similar untreate ...19902133006
antibacteriophage action on the larvicidal activity of bacillus thuringiensis h-14 and bacillus sphaericus against culex pipiens.an organically polluted mosquito breeding water was tested for the presence of bacteriophages which could inhibit the larvicidal activity of b. thuringiensis h-14 and b. sphaericus. more than one bacteriophage were isolated which could inhibit the tested bacteria. the sensitivity of the two bacterial species to 12 antibiotics was tested. two of them, showed no antibacterial action, were selected and considered as antivirus agents in the bacteriophage assays; namely, amoxycillin and co-trimoxazol ...19902133905
identification and characterization of glycosylphosphatidylinositol-linked schistosoma mansoni adult worm immunogens.metabolic radiolabeling of adult worms of schistosoma mansoni with [3h]myristic acid has revealed that the fatty acid is incorporated into more than 15 proteins. we have shown that two of these proteins, a 200-kda glycoprotein known to be exposed on the surface of the adult worm following praziquantel treatment and a 22-kda glycoprotein that shows an enhanced immune reactivity with sera of vaccinated mice, are anchored to the adult worm membrane via a glycosylphosphatidylinositol (gpi) linkage. ...19902139172
[control of simuliidae with an emulsifiable concentrate of bacillus thuringiensis].the effects of the three flowable concentrate formulations of bacillus thuringiensis var. israelensis (h-14): teknar (zoecon, sandoz inc.), vectobac (abbott labs.), and bactimos (biochem, solvay labs.) against simulium pertinax were evaluated in 24 streams in the north littoral zone of são paulo state, brazil. there was no significant difference in effective carry (80% or more mortality) among the formulations when applied at the rate of 10 mg/liter for one minute. there was a strong correlation ...19902143072
[substantiation of safe levels of biological environmental pollutants (dendrobacillin, thuringin and dietary protein) in reservoir water]. 19902144498
structural features of the lipopeptidophosphoglycan from trypanosoma cruzi common with the glycophosphatidylinositol anchors.the lipopeptidophosphoglycan (lppg) from trypanosoma cruzi, a major constituent of the plasma membrane of epimastigote forms, has been now extracted with butanol/water from delipidated cells and purified by hydrophobic chromatography. we have found that the lppg undergoes two reactions, characteristic of the glycosylphosphatidylinositol anchors: (a) cleavage of the ceramide by phosphatidylinositol-specific phospholipase c (ptdins-specific phospholipase c) from bacillus thuringiensis, (b) nitrous ...19902145155
[the infection of bacilli by mu cts phage integrated into the plasmid].the infection of bacillus thuringiensis, b. cereus, b. mesentericus and b. polymyxa strains with temperate e. coli bacteriophage mu cts62 integrated into plasmid rp4 under conditions of conjugative transfer is shown possible. the investigated strains of bacilli are not able to produce intact phage particles but they acquire the thermosensitive property determined by the phage genome. gel electrophoresis and blot hybridization of dna have confirmed the transfer of mu cts62 genome or a part of it ...19902145498
the bacillus thuringiensis delta-endotoxin. evidence for a two domain structure of the minimal toxic fragment.the conformational characteristics of the minimal toxic fragment of the delta-endotoxin from bacillus thuringiensis berliner 1715 were examined by fluorescence and circular dichroism spectroscopy. this insecticidal protein, specifically toxic to lepidopteran species, was found to consist of two structural domains. experimental evidence for this conclusion was provided by biphasic guanidine hydrochloride unfolding curves at different ph values and electrophoretic patterns of protease digests. two ...19902153130
bioconversion of leukotriene d4 by lung dipeptidase.sheep lung dipeptidase was released from a lung membrane preparation by digestion with phosphatidylinositol-specific phospholipase c from bacillus thuringiensis. the total enzyme activity released into the supernatant was 4- to 5-fold greater than that measured in the intact membrane prior to solubilization. the release of the peptidase from the membrane by this treatment is typical of proteins anchored to the lipid bilayer by a covalent attachment of phosphatidylinositol via a c-terminal glycol ...19902153408
n-methyl-d-aspartate and quisqualate/dl-alpha-amino-3-hydroxy-5- methylisoxazole-4-propionic acid receptors: differential regulation by phospholipase c treatment.the effect of phospholipase c (plc) treatment of rat brain membranes on the binding properties of excitatory amino acid receptors was investigated using both a phosphsphatidylcholine-hydrolyzing plc from clostridium perfringens and a phosphatidylinositol-specific plc from bacillus thuringiensis. plc from c. perfringens produced an increased affinity of the quisqualate/dl-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (ampa) receptor for its ligand, whereas kainate receptor binding was ...19902154675
toxicity of protease-resistant domains from the delta-endotoxin of bacillus thuringiensis subsp. israelensis in culex quinquefasciatus and aedes aegypti bioassays.the mosquitocidal glycoprotein endotoxin of bacillus thuringiensis subsp. israelensis was digested with chymotrypsin to yield protease-resistant domains which were then separated from smaller protease digestion products by high-performance liquid chromatography. once purified, the domains no longer bound wheat germ agglutinin, a lectin which binds n-acetylglucosamine (glcnac) and glcnac oligomers. purified protease-resistant domains were as toxic for culex quinquefasciatus larvae as intact solub ...19902155575
influence of media composition on the production of delta-endotoxin by bacillus thuringiensis var. thuringiensis.powders of edible leguminous seeds, greengram (vigna radiata) or soybean (glycine max), were used as the major protein source with different combinations of soluble starch and/or cane sugar molasses as the major carbohydrate source for the production of delta-endotoxin by bacillus thuringiensis var. thuringiensis serotype 1 in submerged fermentation. the primary product (lyophilized with 6 g of lactose) yield was 8.7 to 9.1 g/liter from media with dehusked greengram powder and 9.7 to 10.3 g/lite ...19902156939
expression of bacillus thuringiensis delta-endotoxin genes during vegetative growth.bacillus thuringiensis delta-endotoxin (crystal protein) genes are normally expressed only during sporulation. it is possible to produce crystal protein during vegetative growth by placing b. thuringiensis crystal protein genes downstream of a strong vegetative promoter. by removing a possible transcriptional terminator of the tetracycline resistance gene of pbc16 and inserting a multiple cloning site, delta-endotoxin genes can be cloned downstream from the tetracycline resistance gene promoter. ...19902160219
evidence that the inositol phospholipids are necessary for exocytosis. loss of inositol phospholipids and inhibition of secretion in permeabilized cells caused by a bacterial phospholipase c and removal of atp.we directly manipulated the levels of ptdins, ptdinsp and ptdinsp2 in digitonin-treated adrenal chromaffin cells with a bacterial phospholipase c (plc) from bacillus thuringiensis and by removal of atp. the ptdins-plc acted intracellularly to cause a large decrease in [3h]inositol- or [32p]phosphate-labelled ptdins, but did not directly hydrolyse ptdinsp or ptdinsp2. [3h]ptdinsp and [3h]ptdinsp2 levels declined markedly, probably because of the action of phosphatases in the absence of synthesis. ...19902160809
human placental carboxypeptidase m is anchored by a glycosyl-phosphatidylinositol moiety.basic carboxypeptidase activity was released from human placental membranes on treatment with phosphatidylinositol-specific phospholipase c of bacillus thuringiensis. the enzyme was successively purified to homogeneity by sds-polyacrylamide gel electrophoresis. the molecular nature and some catalytic properties of the purified enzyme revealed that it is identical with recently described basic carboxypeptidase m (r.a. skidgel et al. j. biol. chem. 264 (4) 1989 2236-2241).19902161229
the toxicity of two bacillus thuringiensis delta-endotoxins to gypsy moth larvae is inversely related to the affinity of binding sites on midgut brush border membranes for the toxins.the delta-endotoxin from bacillus thuringiensis subspecies kurstaki strain hd1-9 is almost 400 times more potent than the delta-endotoxin from strain hd-73 as a gypsy moth larvicide. the two delta-endotoxins compete for a high-affinity binding site on the brush border membrane of larval gypsy moth midguts. the affinity for the delta-endotoxin from strain hd-73 is much greater than the affinity for the delta-endotoxin from strain hd1-9.19902161350
construction of genetically engineered baculovirus insecticides containing the bacillus thuringiensis subsp. kurstaki hd-73 delta endotoxin.the delta-endotoxin gene from bacillus thuringiensis subsp. kurstaki hd-73 was inserted into autographa californica nuclear polyhedrosis virus (acmnpv) using two transfer vector systems. in the first, the delta-endotoxin gene was placed under the control of the polyhedrin gene promoter in lieu of the polyhedrin coding sequences, thus deriving a polyhedrin-negative virus. in the second, it was inserted under the control of a copy of the acmnpv p10 promoter positioned upstream of the polyhedrin ge ...19902165136
light microscope immunolocation of bacillus thuringiensis kurstaki delta-endotoxin in the midgut and malpighian tubules of the tobacco budworm, heliothis virescens.light microscope immunofluorescence was used to localize the membrane binding of bacillus thuringiensis kurstaki 63-kda delta-endotoxin in heliothis virescens midgut and malpighian tubules. staining was observed along all exposed mucosal (apical microvillar) plasma membranes. interpretation of the serosal (basal) plasma membrane staining was complicated because the basal lamina also stained. the results suggest that the toxin binds to all exposed plasma membranes without apparent specificity for ...19902165507
antibody against bacillus thuringiensis phosphatidylinositol-phospholipase c: some examples of its potential uses.we have purified the phosphatidylinositol-phospholipase c enzyme from the bacterium bacillus thuringiensis. this enzyme is able to release in soluble form molecules which are anchored to membranes via a glycan-phosphatidylinositol group. it exhibits a molecular weight of 33-35 kda. we raised polyclonal antisera against the molecule and used them in immunoblot as well as radioimmunoassays for enzyme detection. this last technique should facilitate monitoring of chromatographic steps during enzyme ...19902166707
bacillus thuringiensis insecticidal delta-endotoxin: diversity of crystal proteins and its relatedness to the toxicity spectrum.bacillus thuringiensis strains produce crystal delta-endotoxins which exhibit a diverse toxicity spectrum. in order to explore the basis of toxin specificity, a comparison of the activity of 13 strains belonging to seven serotypes was made against three insect species. the delta-endotoxin crystals were purified and their polypeptide composition analyzed by sds-page. among the strains studied, the delta-endotoxins consist of a variety of crystal proteins in the 60-144 kda size range. on the basis ...19902166785
comparative analysis of the individual protoxin components in p1 crystals of bacillus thuringiensis subsp. kurstaki isolates nrd-12 and hd-1.two commercially important strains (nrd-12 and hd-1) of the entomopathogenic bacterium bacillus thuringiensis subsp. kurstaki each contain three genes of partially identical sequence coding for three classes of 130-135 kda protoxins (termed the 4.5, 5.3 and 6.6 protoxins) that display toxicity towards various lepidopteran larvae. these gene products combine to form the intracellular bipyramidal p1 crystal. each of the genes from both strains was cloned and expressed in escherichia coli. analysis ...19902167072
the construction of bacillus thuringiensis strains expressing novel entomocidal delta-endotoxin combinations.using our recently reported method of electroporation to transform bacillus thuringiensis [bone & ellar (1989) fems microbiol. lett. 58, 171-178], cloned b. thuringiensis entomocidal delta-endotoxin genes have been introduced into several native b. thuringiensis strains. in many cases the resulting transformants expressed both their native toxins and the cloned toxin, producing strains with broader toxicity spectra. the introduction of the var. tenebrionis toxin gene into b. thuringiensis var. i ...19902168699
hyperexpression of a bacillus thuringiensis delta-endotoxin-encoding gene in escherichia coli: properties of the product.conditions for hyperexpression, in escherichia coli, of the bacillus thuringiensis var, kurstaki gene, cryia9(c)73, encoding an insecticidal crystal protein, cryia(c)73, were investigated by varying the promoter type, host cell, plasmid copy number, the second codon and number of terminators. the cryia(c)73 gene was cloned into three e. coli expression vectors, pkk223-3 (ptac promoter), pet-3a (p phi 10 promoter), and puc19 (ptac promoter). the level of cryia(c)73 expression was measured by elis ...19902172088
[expression of delta-endotoxin gene from bacillus thuringiensis var. berliner 1715 in escherichia coli and bacillus megaterium cells].effects of the structure of plasmids carrying the cloned delta-endotoxin gene (tox) ot bacillus thuringiensis and of the culture media on the expression of the gene have been studied. the dna region located upstream from the crystal protein gene promoter inhibited the expression of the tox gene in escherichia coli cells, but enhanced the expression in bacillus megaterium cells grown in lb medium. the upstream dna region did not affect the tox gene expression when bacillus megaterium cells were g ...19902172806
structural and genetic organization of is232, a new insertion sequence of bacillus thuringiensis.in the bacillus thuringiensis strains toxic for the lepidopteran larvae, the delta-endotoxin genes cryia are frequently found within a composite transposonlike structure flanked by two inverted repeat sequences. we report that these elements are true insertion sequences and designate them is232. is232 is a 2,184-bp element and is delimited by two imperfect inverted repeats (28 of 37 bp are identical). two adjacent open reading frames, overlapping for three codons, span almost the entire sequence ...19902174857
[correlation between insecticidal and antibiotic activities of bacillus thuringiensis parasporal crystals].the work was concerned with studying the insecticide and antibiotic activities of solutions containing parasporal crystals of several bacillus thuringiensis subspecies. the correlation coefficients of these values were determined. a direct correlation was established between the insecticide and antibiotic activities of solutions of parasporal crystals from several b. thuringiensis subspecies. therefore, the quality of bacterial insecticides can be controlled by assaying the antibiotic activity o ...19902175834
[inclusion body formation and renaturation of recombinant proteins]. 19902176307
a simple haemolytic method for quantitation of the delta endotoxin of bacillus thuringiensis subsp. israelensis from crude samples.a simple haemolytic assay method for quantitative estimation of the delta endotoxin of bacillus thuringiensis subsp. israelensis from a crude preparation has been developed. the method has several advantages over mosquito-larvicidal methods of assay as it is inexpensive, highly sensitive and easier to run and can be used for performing a reasonably large number of assays rapidly with high precision and with a coefficient of variation that does not exceed 1.96%.19902177053
an in vitro system for testing bacillus thuringiensis toxins: the lawn assay.a cell assay system was developed that allows bacillus thuringiensis delta-endotoxins activated at high ph (10.5) to be tested in vitro without causing alkaline injury to target cells. the assay is carried out on a lawn of gel-suspended cells, requires only 1 microliter of sample per dose, and is quantitative, rapid, and sensitive. the threshold dose for toxicity of b. thuringiensis subsp. kurstaki hd-73 with ipri-cf-1 cells was 24 pg protein. the assay is also very useful for identifying antibo ...19902177079
subdomain organization of bacillus thuringiensis entomocidal proteins' n-terminal domains.n-terminal domain (65 kd) of delta-endotoxin produced by bacillus thuringiensis ssp. alesti, as shown by limited proteolysis, consists of two subdomains of molecular mass 30 and 33 kd that correspond, respectively, to conservative and variable regions of the delta-endotoxin primary structure. furthermore, proteolysis of these subdomains leads to their conversion into at least two fragments of molecular mass 10 kd stable to proteinase action. such a pattern of molecular organization appears to be ...19902177337
resistance to bacillus thuringiensis by the indian meal moth, plodia interpunctella: comparison of midgut proteinases from susceptible and resistant larvae.midgut homogenates from susceptible and resistant strains of the indian meal moth, plodia interpunctella, were compared for their ability to activate the entomocidal parasporal crystal protein from bacillus thuringiensis. the properties of midgut proteinases from both types of larvae were also examined. electrophoretic patterns of crystal protein from b. thuringiensis subspecies kurstaki (hd-1) and aizawai (hd-133 and hd-144) were virtually unchanged following digestion by either type of midgut ...19902181026
construction of an efficient overproducer clone of hinfi restriction endonuclease using the polymerase chain reaction.we describe the use of the polymerase chain reaction (pcr) technique to alter transcriptional and translational signals surrounding a gene so as to achieve overexpression in escherichia coli. by changing the ribosome-binding site sequence preceding the hinfir gene to match the consensus e. coli signal and by adding a transcription terminator sequence immediately following the gene, the yield of hinfi was increased about tenfold over that obtained from the natural haemophilus influenzae signals. ...19902187744
unusual proteolysis of the protoxin and toxin from bacillus thuringiensis. structural implications.trypsin is shown to generate an insecticidal toxin from the 130-kda protoxin of bacillus thuringiensis subsp. kurstaki hd-73 by an unusual proteolytic process. seven specific cleavages are shown to occur in an ordered sequence starting at the c-terminus of the protoxin and proceeding toward the n-terminal region. at each step, c-terminal fragments of approximately 10 kda are produced and rapidly proteolyzed to small peptides. the sequential proteolysis ends with a 67-kda toxin which is resistant ...19902190826
molecular cloning of the 130-kilodalton mosquitocidal delta-endotoxin gene of bacillus thuringiensis subsp. israelensis in bacillus sphaericus.a 3.7-kilobase (kb) xbai fragment harboring the cryivb gene (l. thorne, f. garduno, t. thompson, d. decker, m. a. zounes, m. wild, a. m. walfield, and t. j. pollock, j. bacteriol. 166:801-811, 1986) which encoded a 130-kilodalton (kda) mosquitocidal toxin from a 110-kb plasmid of bacillus thuringiensis subsp. israelensis 4q2-72 was cloned into puc12 and transformed into escherichia coli. the clone with a recombinant plasmid (designated pbt8) was toxic to aedes aegypti larvae. the fragment (3.7 k ...19902200339
[agriculture-health interface in the field of epidemiology of vector-borne diseases and the control of vectors].this paper is a review of the interactions between agriculture and vector borne diseases. rain forest clearing makes possible the development of heliophilous species of anophelines and snails leading to an increase of malaria and schistosomiasis in africa. but in asia, clearing is a control method against anopheles balabacensis, an important malaria vector. clearing of forest galleries is followed by the disappearance of shore-dwelling tsetse flies. woodcutters and pioneer farmers are contaminat ...19902208469
nucleotide sequence and deduced amino acid sequence of new lepidoptera-specific crystal protein gene from bacillus thuringiensis. 19902216728
nucleotide sequence and deduced amino acid sequence of a cryia(c) gene variant from bacillus thuringiensis. 19902216729
field evaluation of bacillus thuringiensis var. israelensis for control of black flies in the north littoral zone of brazil's são paulo state.the impact of three flowable concentrate formulations of bacillus thuringiensis var. israelensis (h-14) upon simulium pertinax larvae was evaluated in 24 coastal streams of brazil's são paulo state. while no significant differences were found regarding the three formulations' effectiveness, significant correlations were found between the discharge rates of individual streams and the distances over which at least two of the formulations were carried effectively downstream to produce 80% mortality ...19902224330
isolation of indigenous larvicidal microbial control agents of mosquitos: the malaysian experience.a nationwide screening program searching for microbial control agents of mosquitos was initiated in malaysia in 1986. a total of 725 samples were collected and 2,394 bacterial colonies were isolated and screened for larvicidal activity. from such screening, 20 bacillus thuringiensis, 6 b. sphaericus, 1 clostridium bifermentans and 2 pseudomonas pseudomallei larvicidal isolates were obtained. of these, a new b. thuringiensis named as subspecies malaysianensis was found, while the c. bifermentans ...19902237596
specificity-determining regions of a lepidopteran-specific insecticidal protein produced by bacillus thuringiensis.the lepidopteran-specific, insecticidal crystal proteins of bacillus thuringiensis vary in toxicity to different species of lepidopteran larvae. we report studies of cryia(a) and cryia(c), two related proteins that have different degrees of toxicity to heliothis virescens yet very similar degrees of toxicity to manduca sexta. the amino acid differences between these proteins are located primarily between residues 280 and 722. we have constructed a series of chimeric proteins and determined their ...19902250000
the fate of bacillus thuringiensis var. israelensis in b. thuringiensis var. israelensis-killed pupae of aedes aegypti.carcasses of mosquito larvae killed by bacillus thuringiensis var. israelensis allow its complete growth cycle (germination, vegetative growth, and sporulation), thus becoming toxic themselves to scavenging larvae. in this study, we demonstrate that the bacterium is capable of inducing death of aedes aegypti pupae and of recycling in the resulting carcasses. b. thuringiensis var. israelensis-killed pupae were obtained by treating 40-hr-old synchronized fourth instar larvae with a low dose of spo ...19902250101
[survey of bacillus thuringiensis and bacillus sphaericus from soils of four provinces of china and their principal biological properties].a number of isolates of bacillus thuringiensis and bacillus sphaericus were obtained from soils of southwestern area and shaanxi province of china. among isolates of b. thuringiensis were under 13 sorts of serotype in total of 23 sorts of b. thuringiensis and about 20% of auto-agglutinate strains. rules of ecologic distribution of two sorts of bacteria were analysed. toxicities on six species of insects, morphology and crystal proteins of b. thuringiensis, as well as toxicities, morphology and c ...19902251830
a novel bacillus thuringiensis gene encoding a spodoptera exigua-specific crystal protein.only one of the four lepidoptera-specific crystal protein subclasses (cryic) bacillus thuringiensis was previously shown to be highly toxic against several spodoptera species. by using a cryic-derived nucleotide probe, dna from 25 different strains of b. thuringiensis was screened for the presence of homologous sequences. a putative crystal protein gene, considerably different from the cryic gene subclass, was identified in the dna of strain 4f1 (serotype kenyae) and cloned in escherichia coli. ...19902254254
sprayable self-encapsulating starch formulations for bacillus thuringiensis.under glasshouse conditions, various cornstarches and adjuvants were examined as encapsulating agents in sprayable formulations for bacillus thuringiensis subsp. kurstaki berliner. when these materials were suspended in water and tested for physical factors such as viscosity, clumping, and retention on plant surfaces, a range of responses was observed. all formulations tested had acceptable viscosity, but some formulations clumped. when applied to cotton leaves, certain formulations remained les ...19902258512
nucleotide sequence of a novel crystal protein gene isolated from bacillus thuringiensis subspecies kenyae. 19902259636
novel cloning vectors for bacillus thuringiensis.seven replication origins from resident plasmids of bacillus thuringienis subsp. kurstaki hd263 and hd73 were cloned in escherichia coli. three of these replication origins, originating from plasmids of 43, 44, and 60 mda, were used to construct a set of compatible shuttle vectors that exhibit structural and segregational stability in the cry- strain b. thuringiensis hd73-26. these shuttle vectors, peg597, peg853, and peg854, were designed with rare restriction sites that permit various adaptati ...19902268153
folding and unfolding of the protoxin from bacillus thuringiensis: evidence that the toxic moiety is present in an active conformation.the action of trypsin or papain on the 130-kda crystal protein (protoxin) from bacillus thuringiensis subsp. kurstaki hd-73 yields a 67-kda proteinase-resistant toxic fragment (toxin) which is derived from the n-terminal half of the molecule. sensitivity to proteolysis and fluorescence emission spectroscopy showed that the toxin unfolded to a much greater extent in 6 m guanidinium chloride (guhcl) than in 8 m urea. protoxin also unfolded extensively in 6 m guhcl, whereas in 8 m urea only the c-t ...19902271692
[bacillus thuringiensis subsp. toguchini--a new subspecies of crystal-forming bacteria].a new subspecies of b. thuringiensis subsp. toguchini has been isolated from soil in novosibirsk region. new subspecies forms elliptic crystals. biologically and serologically it is different from other known subspecies.19902273188
activation and germination of bacillus thuringiensis spores in manduca sexta larval gut fluid.incubation of bacillus thuringiensis hd-1 spores in the larval gut fluid of manduca sexta (tobacco hornworm) resulted in increased viable counts, conversion to phase-dark spores, and a loss of absorbance in spore suspensions, indicative of spore germination. heat-activated and untreated spores incubated in water did not exhibit these changes. only when spores were heat activated and incubated in germinants l-alanine and adenosine did changes in the spores approximate those observed in gut fluid. ...19902273289
specificity and efficacy of purified bacillus thuringiensis proteins against agronomically important insects.the host range and relative efficacy of three purified bacillus thuringiensis insect control proteins were determined against 17 different agronomically important insects representing five orders and one species of mite. the three b. thuringiensis proteins were single gene products from b. thuringiensis ssp. kurstaki hd-1 (cryia(b)) and hd-73 (cryia(c)), both lepidopteran-specific proteins, and b. thuringiensis ssp. tenebrionis (cryiiia), a coleopteran-specific protein. seven insects showed sens ...19902273290
bacillus thuringiensis subspecies neoleonensis serotype h-24, a new subspecies which produces a triangular crystal. 19902273292
characterization of the bacillus thuringiensis strains isolated from taiwan.over 100 bacillus thuringiensis (bt) isolates which produced phase bright inclusions have been isolated from soil samples from different areas in taiwan. three types of crystal proteins were visualized by phase contrast microscopy. among these isolates, only 14 different types of plasmid profiles have been observed. they all possess a variety of plasmids ranging from a few kb to around 250 kb in size. with respect to the crystal protein profiles, the plasmid profiles, and the shapes of crystal p ...19902274596
mechanism of insect resistance to the microbial insecticide bacillus thuringiensis.receptor binding studies show that resistance of a laboratory-selected plodia interpunctella strain to a bacillus thuringiensis insecticidal crystal protein (icp) is correlated with a 50-fold reduction in affinity of the membrane receptor for this protein. the strain is sensitive to a second type of icp that apparently recognizes a different receptor. understanding the mechanism of resistance will provide strategies to prevent or delay resistance and hence prolong the usefulness of b. thuringien ...19902294593
molecular forms of acetylcholinesterase in two sublines of human erythroleukemia k562 cells. sensitivity or resistance to phosphatidylinositol-specific phospholipase c and biosynthesis.acetylcholinesterase (ache) in k562 cells exists in two molecular forms. the major form, an amphiphilic dimer (g2a) which sediments at 5.3 s, and the minor form, an amphiphilic monomer (g1a) which sediments at 3.5 s. extraction in the presence of the sulfhydryl alkylating agent n-ethylmaleimide was required to preserve the g2a form. in triton x-100 extracts of the subline k562-243, phosphatidylinositol-specific phospholipase c (ptdins-plc) from bacillus thuringiensis converted most of the g2a ac ...19902298208
transfer of the toxin protein genes of bacillus sphaericus into bacillus thuringiensis subsp. israelensis and their expression.the genes encoding the toxic determinants of bacillus sphaericus have been expressed in a nontoxic and a toxic strain of bacillus thuringiensis subsp. israelensis. in both cases, the b. sphaericus toxin proteins were produced at a high level during sporulation of b. thuringiensis and accumulated as crystalline structures. b. thuringiensis transformants expressing b. sphaericus and b. thuringiensis subsp. israelensis toxins did not show a significant enhancement of toxicity against aedes aegypti, ...19902306087
occurrence of two pathotypes in bacillus thuringiensis subsp. fukuokaensis (flagellar serotype 3a:3d:3e). 19902319163
nucleotide sequence of a coleopteran-active toxin gene from a new isolate of bacillus thuringiensis subsp. tolworthi. 19902320431
heterologous expression of a mutated toxin gene from bacillus thuringiensis subsp. tenebrionis.using oligonucleotide probes we have isolated a dna fragment encoding an insecticidal toxin of the coleopteran specific bacillus thuringiensis subsp. tenebrionis. the gene was altered by site directed mutagenesis at its 5'-end and adapted for general cloning and expression purposes with a linker including a start codon and new restriction sites. the constructs were inserted into several vector plasmids and expressed in escherichia coli. expression e. coli was strongly enhanced by the lac-promote ...19902323547
salt marsh mosquito control in portsmouth, rhode island.the portsmouth, rhode island mosquito control program used granular bacillus thuringiensis var. israelensis to successfully control salt marsh mosquitoes in a 9 acre salt marsh while monitoring for, planning and implementing small scale open marsh water management in the marsh. single season larviciding costs were roughly 4% that of contracted open marsh water management in this marsh.19902324720
field efficacy of vectobac-12as and vectobac-24as against black fly larvae in new brunswick streams (diptera: simuliidae).the control of black fly larvae using 2 aqueous suspension formulations of bacillus thuringiensis, serotype h-14 was evaluated in 6 trials on small and large sized streams in new brunswick. applications equivalent to 25 ppm (vectobac-12as) or 12.5 ppm (vectobac-24as) over a 1-min period resulted in 100% control of black fly larvae up to 3 km downstream of the application point. over the 6 trials, effective carry was seen to increase with increased stream discharge which varied from as low as 0.8 ...19902324724
directed mutagenesis of selected regions of a bacillus thuringiensis entomocidal protein.comparison of the sequences of bacillus thuringiensis entomocidal toxins of widely differing specificity reveals six conserved domains. the role of one of the most highly conserved domains (d1) located near the n-terminus has been investigated by site directed mutagenesis at two positions. although preliminary results indicate that the capacity of the mutants to bind to putative receptors on the plasma membrane of susceptible cells was unaffected, toxicity in vivo was reduced by 70-80%. the role ...19902332159
methacrylate embedding as a new technique for histopathological studies on the effect of bacillus thuringiensis against culex pipiens.studies on the pathogen bacillus thuringiensis in egypt and its possible role as a biological control agent have been reviewed. more emphasis in research was given to some lepidopterous cotton pests and few other species. histopathological changes in b. thuringiensis treated larvae could be observed in the midgut. the methacrylate embedding technique achieved satisfactory results in concern of better preservation of histological fine details.19902332647
receptors on the brush border membrane of the insect midgut as determinants of the specificity of bacillus thuringiensis delta-endotoxins.to investigate the biochemical basis of the differences in the insecticidal spectrum of bacillus thuringiensis insecticidal crystal proteins (icps), we performed membrane binding and toxicity assays with three different icps and three lepidopteran species. the three icps have different toxicity patterns in the three selected target species. binding studies with these 125i-labeled icps revealed high-affinity saturable binding to brush border membrane vesicles of the sensitive species. icps with n ...19902339890
secondary structure of the entomocidal toxin from bacillus thuringiensis subsp. kurstaki hd-73.the secondary structure of the toxin from bacillus thuringiensis subsp. kurstaki (btk) hd-73 was estimated by raman, infrared, and circular dichroism spectroscopy, and by predictive methods. circular dichroism and infrared spectroscopy gave an estimate of 33-40% alpha-helix, whereas raman and predictive methods gave approximately 20%. raman and circular dichroism spectra, as well as predictive methods, indicated that the toxin contains 32-40% beta-sheet structure, whereas infrared spectroscopy g ...19902340079
location of the dipteran specificity region in a lepidopteran-dipteran crystal protein from bacillus thuringiensis.two highly related crystal protein genes from bacillus thuringiensis subsp. kurstaki hd-1, designated cryiia and cryiib (previously named cryb1 and cryb2, respectively), were used to study host range specificity. their respective gene products are 87% identical but exhibit different toxicity spectra; cryiia is toxic to both mosquito and tobacco hornworm larvae, whereas cryiib is toxic only to the latter. hybrids of the cryiia and cryiib genes were generated, and their resultant gene products wer ...19902345127
identification of beta-exotoxin production, plasmids encoding beta-exotoxin, and a new exotoxin in bacillus thuringiensis by using high-performance liquid chromatography.an improved high-performance liquid chromatography separation was developed to detect and quantify beta-exotoxin production in bacillus thuringiensis culture supernatants. exotoxin production was assigned to a plasmid in five strains, from three subspecies (b. thuringiensis subsp. thuringiensis serotype 1, b. thuringiensis subsp. tolworthi serotype 9, and b. thuringiensis subsp. darmstadiensis serotype 10). a new exotoxin, called type ii beta-exotoxin in this report, was discovered in b. thuring ...19902345141
clearance of bacillus sphaericus and bacillus thuringiensis ssp. israelensis from mammals.the maximum recovery period following topical ocular instillation and intraperitoneal injection of two preparations of bacillus thuringiensis ssp. israelensis de barjac and two preparations of bacillus sphaericus 2362 was evaluated in rabbits and mice. b. sphaericus 2362 persisted for 8 wk after administration to the conjunctival cul-de-sac of rabbits; b. thuringiensis ssp. israelensis persisted for 1 wk. infection was not evident, but both entomopathogens were recovered from flushed and unflush ...19902345219
bacillus thuringiensis potency bioassays against heliothis armigera, earias insulana, and spodoptera littoralis larvae based on standardized diets.bacillus thuringiensis screening programs based on the official potency bioassay using third-instar larvae and on a neonate bioassay were developed for heliothis armigera, earias insulana, and spondoptera littoralis. in these bioassays, the diets were standardized to be suitable, with minor modifications, for feeding of the three lepidopterans. the bioassay protocol was based on determination of the lc50 of the microbial standard hd-1-s-80 in the insects susceptible to b. thuringiensis var. kurs ...19902351843
enhancement of bacillus thuringiensis subsp. kurstaki toxin activity by cell lysates. 19902351846
[the quantitative determination of bacillus thuringiensis beta-exotoxin in insecticidal biopreparations].a method of quantitative determination of beta-exotoxin content in liquid and dry bioformulations has been developed. the method includes a thin-layer chromatography to isolate beta-exotoxin from accompanying nucleotides, the further desorption of a single beta-exotoxin spot by water and to carry out spectrophotometry at 259 and 330 nm. beta-exotoxin content in industrial formulations bitoxibacillin and turingin i has been determined. the results obtained correspond to the nmr 1h spectroscopy da ...19902354222
public health implications of the microbial pesticide bacillus thuringiensis: an epidemiological study, oregon, 1985-86.bacillus thuringiensis var. kurstaki (b.t.-k) is a microbial pesticide which has been widely used for over 30 years. its safety for a human population living in sprayed areas has never been tested. surveillance for human infections caused by b.t.-k among lane county, oregon residents was conducted during two seasons of aerial b.t.-k spraying for gypsy moth control. bacillus isolates from cultures obtained for routine clinical purposes were tested for presence of bacillus thuringiensis (b.t.). de ...19902356910
[presence of flagellar antigenic subfactors in serotype 1 of bacillus thuringiensis].the strain g was isolated from a dead army worm (leucania separata walker) in corn field, at hebei. it has the typical morphological characteristics of bacillus thuringiensis. the serological analysis showed that the flagellar suspensions of the strain g was agglutinated only by the antisera against the h1 antigen and not by the antisera against the other 22 known h-antigens. the agglutination titre was 1:6,400. the flagellar suspension of the serotype 1, subsp. thuringiensis, was agglutinated b ...19902360326
cloning and heterospecific expression of the resistance determinant vana encoding high-level resistance to glycopeptides in enterococcus faecium bm4147.fragments of plasmid pip816, which confers high-level glycopeptide resistance in enterococcus faecium bm4147, were cloned into a conjugative gram-negative-gram-positive shuttle vector. the resulting hybrids were transferred by conjugation from escherichia coli to enterococcus faecalis and bacillus thuringiensis. a 4-kilobase ecori fragment from pip816 was found to confer vancomycin resistance in these hosts but not in e. coli or bacillus subtilis.19902360831
simple method for the isolation of the antilepidopteran toxin from bacillus thuringiensis subsp. kurstaki.a protein with a molecular mass of 66 kda was isolated by a simple, rapid, and inexpensive method, using 3-n-morpholinopropanesulfonic acid, potassium thiocyanate, and dithiothreitol, from a mixture of spores, parasporal crystals, and cell debris of bacillus thuringiensis subsp. kurstaki. the protein was active against the third instar larvae of trichoplusia ni, was soluble in 19 mm na2co3, and was characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and confirmed as the in ...19902360990
[the effects of six kinds of insecticides on gamasid mites].the present paper reports on the results of six kinds including 14 chemical or biological insecticides on the gamasid mites. (1) using organophosphorus compounds such as quinothion, supracide, bromochlophus, sumithion at a dose of 0.2g per m2, at a dose of 1 g per m2 abate, and malathion at a dose of 49 per m2, they were all sufficient to produce 100% mortality on the mites eulaelaps stabularis; trichlorphon at a dose of 4g per m2 produced 96.4% kill of the mites. (2) organochloride insecticide ...19902364806
maintenance of effective control of simulium damnosum in the face of insecticide resistance.the control of onchocerciasis through reduction of its vector simulium damnosum depends on highly effective insecticide treatments directed against the larvae. as these treatments must be applied weekly over wide areas for many years, ideal conditions for the development of resistance have been created. resistance to organophosphate compounds has occurred. to maintain effective vector control, an intense operational research effort has been necessary. close and constant monitoring of susceptibil ...19902378230
plasmid transfer between strains of bacillus thuringiensis infecting galleria mellonella and spodoptera littoralis.to determine the possibility of plasmid transfer occurring between strains of bacillus thuringiensis in infected lepidopterous larvae, galleria mellonella and spodoptera littoralis were infected with two or more strains of b. thuringiensis and the resulting bacteria from the dead insects were examined for plasmid transfer. transfer rates of plasmids coding for crystal production and tetracycline resistance were high, reaching levels similar to those obtained in laboratory broth cultures. transfe ...19902383006
[application and environmental impact of the biocontrol agent--bacillus thuringiensis subsp. israelensis for vector control].in 1976, goldberg and margalit found a potent isolate of bacillus thuringiensis subsp. israelensis, which has great mosquitocidal activity and was commercialized within 5 years in the usa. it is now the only bio-control agent on the market for vector control worldwide. because of concerns about environmental pollution and ecological preservation, vector control can no longer be solely dependent on the use of chemicals. it appears that the best strategy is to be integrated with biological control ...19902402021
[applications of bacterial pathogens to the mosquito control].both bacillus thuringiensis subsp. isrealensis (bti) and bacillus sphaericus are common bacteria found in a variety of soil and aquatic habitats. some strains of them can produce a protein crystal, called parasporal body (or crystal) beside the spore in the cell during sporulation, and it is toxic if eaten by mosquito larvae. as the parasporal bodies are ingested into a mosquito digestive tract, they will be digested and activated by certain enzymes in alkaline digestive juice. the activated tox ...19902402023
preliminary field evaluation of a malaysian isolate of bacillus thuringiensis serotype h-14 against culex pseudovishnui. 19902402673
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