Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| the phylloplane as a source of bacillus thuringiensis variants. | novel variants of bacillus thuringiensis were isolated from the phylloplane of deciduous and conifer trees as well as of other plants. these isolates displayed a range of toxicity towards trichoplusia ni. immunoblot and toxin protein analysis indicate that these strains included representatives of the three principal b. thuringiensis pathotypes active against larvae of the orders lepidoptera, diptera, and coleoptera. we propose that b. thuringiensis be considered part of the common leaf microflo ... | 1991 | 16348400 |
| specificity of activated cryia proteins from bacillus thuringiensis subsp. kurstaki hd-1 for defoliating forest lepidoptera. | the insecticidal activity of the cryia(a), cryia(b), and cryia(c) toxins from bacillus thuringiensis subsp. kurstaki hd-1 was determined in force-feeding experiments with larvae of choristoneura fumiferana, c. occidentalis, c. pinus, lymantria dispar, orgyia leucostigma, malacosoma disstria, and actebia fennica. the toxins were obtained from cloned protoxin genes expressed in escherichia coli. the protoxins were activated with gut juice from bombyx mori larvae. biological activity of the individ ... | 1991 | 16348504 |
| construction of novel bacillus thuringiensis strains with different insecticidal activities by transduction and transformation. | the shuttle vector pht3101 and its derivative pht408, bearing a copy of a cryia(a) delta-endotoxin gene, were transferred into several bacillus thuringiensis subspecies through phage cp-54ber-mediated transduction, with frequencies ranging from 5 x 10 to 2 x 10 transductant per cfu, depending on the strain and on the plasmid. in cry and cry native recipients, the introduction of the cryia(a) gene resulted in the formation of large bipyramidal crystals that were active against the insect plutella ... | 1992 | 16348674 |
| distribution, frequency, and diversity of bacillus thuringiensis in an animal feed mill. | bacillus thuringiensis was isolated from 36 of 50 residue samples obtained from an animal feed mill (a stored-product environment). of 710 selected colonies having bacillus cereus-b. thuringiensis morphology isolated from the samples, 477 were classified as b. thuringiensis because of production of parasporal delta-endotoxin crystals. there was a diverse population of b. thuringiensis, as revealed by differentiation of the isolates into 36 subgroups by using (i) their spectra of toxicity to the ... | 1992 | 16348699 |
| resistance to toxins from bacillus thuringiensis subsp. kurstaki causes minimal cross-resistance to b. thuringiensis subsp. aizawai in the diamondback moth (lepidoptera: plutellidae). | repeated exposure in the field followed by laboratory selection produced 1,800- to >6,800-fold resistance to formulations of bacillus thuringiensis subsp. kurstaki in larvae of the diamondback moth, plutella xylostella. four toxins from b. thuringiensis subsp. kurstaki [cryia(a), cryia(b), cryia(c), and cryiia] caused significantly less mortality in resistant larvae than in susceptible larvae. resistance to b. thuringiensis subsp. kurstaki formulations and toxins did not affect the response to c ... | 1993 | 16348929 |
| biotinylation of bacillus thuringiensis insecticidal crystal proteins. | biotinylation of bacillus thuringiensis insecticidal crystal proteins (icps) was evaluated for its potential use in an alternative icp screening method and in the characterization of icp receptors. in vivo biological activity of cryia(b), as inferred from bioassays with manduca sexta and ostrinia nubilalis and from histopathological effects on o. nubilalis midgut cells induced by force feeding, was not affected by biotinylation at moderate biotinylation ratios. a competitive radioreceptor assay ... | 1993 | 16348959 |
| two different bacillus thuringiensis delta-endotoxin receptors in the midgut brush border membrane of the european corn borer, ostrinia nubilalis (hübner) (lepidoptera: pyralidae). | binding of three bacillus thuringiensis insecticidal crystal proteins (icps) to the midgut epithelium of ostrinia nubilalis larvae was characterized by performing binding experiments with both isolated brush border membrane vesicles and gut tissue sections. our results demonstrate that two independent icp receptors are present in the brush border of o. nubilalis gut epithelium. from competition binding experiments performed with i-labeled and native icps it was concluded that cryia(b) and cryia( ... | 1993 | 16348960 |
| nonenzymatic glycosylation of lepidopteran-active bacillus thuringiensis protein crystals. | we used high-ph anion-exchange chromatography with pulsed amperometric detection to quantify the monosaccharides covalently attached to bacillus thuringiensis hd-1 (dipel) crystals. the crystals contained 0.54% sugars, including, in decreasing order of prevalence, glucose, fucose, arabinose/rhamnose, galactose, galactosamine, glucosamine, xylose, and mannose. three lines of evidence indicated that these sugars arose from nonenzymatic glycosylation: (i) the sugars could not be removed by n- or o- ... | 1993 | 16349021 |
| expression of cryiva and cryivb genes, independently or in combination, in a crystal-negative strain of bacillus thuringiensis subsp. israelensis. | the cryiva and cryivb genes, encoding the 125- and 135-kda proteins, respectively, of bacillus thuringiensis subsp. israelensis, were cloned either alone or together into a shuttle vector and expressed in a nontoxic strain of b. thuringiensis subsp. israelensis. the cryivb protein was produced at a high level during sporulation and accumulated as inclusions; in contrast, the cryiva polypeptide did not form such structures unless it was cloned on a higher-copy-number plasmid. transcriptional fusi ... | 1993 | 16349095 |
| isolation of bacillus thuringiensis from stored tobacco and lasioderma serricorne (f.). | bacillus thuringiensis was isolated from dried tobacco residues and dead tobacco beetles (lasioderma serricorne (f.); coleoptera: anobiidae) collected in a large number of locations worldwide. eighty-eight samples of stored tobacco were analyzed and yielded 78 b. thuringiensis strains which were characterized on the basis of parasporal crystal morphology, sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles, and the results of an immunoblot analysis of the insecticidal crystal prot ... | 1994 | 16349149 |
| introduction of a lepidopteran-specific insecticidal crystal protein gene of bacillus thuringiensis subsp. kurstaki by conjugal transfer into a bacillus megaterium strain that persists in the cotton phyllosphere. | a lepidopteran toxin gene of the entomopathogen bacillus thuringiensis subsp. kurstaki hd-1 was introduced into a cotton leaf-colonizing bacillus megaterium strain, rs1, by conjugal transfer. rifampin- and nalidixic acid-resistant colonies obtained after cell mating were screened for crystal production by microscopy. a transcipient, b. megaterium rs1-43, was selected by this procedure. southern blot hybridization with both total dna and hindiii-digested dna of the transcipient showed positive si ... | 1994 | 16349152 |
| integrative cloning, expression, and stability of the cryia(c) gene from bacillus thuringiensis subsp. kurstaki in a recombinant strain of clavibacter xyli subsp. cynodontis. | a bacterial endophyte was engineered for insecticidal activity against the european corn borer. the cryia(c) gene from bacillus thuringiensis subsp. kurstaki was introduced into the chromosome of clavibacter xyli subsp. cynodontis by using an integrative plasmid vector. the integration vectors pcg740 and pcg741 included the replicon pgem5zf(+), which is maintained in escherichia coli but not in c. xyli subsp. cynodontis; tetm as a marker for selection in c. xyli subsp. cynodontis; and a chromoso ... | 1994 | 16349179 |
| construction of a bioinsecticidal strain of pseudomonas fluorescens active against the sugarcane borer, eldana saccharina. | a cryia(c) gene was cloned from a native bacillus thuringiensis strain showing activity against the sugarcane borer, eldana saccharina. the sequence of the cloned gene was very similar to that of the b. thuringiensis subsp. kurstaki hd-73 cryia(c) gene. the gene was introduced into an isolate of pseudomonas fluorescens, capable of colonizing sugarcane, on two broad-host-range plasmids, pder405 and pkt240, having copy numbers of 13 and 28, respectively. by using the omegon-km vector, the cry gene ... | 1994 | 16349194 |
| biotinylation of bacillus thuringiensis insecticidal crystal proteins. | [this corrects the article on p. 1821 in vol. 59.]. | 1994 | 16349206 |
| genotypic diversity among bacillus cereus and bacillus thuringiensis strains. | twenty-four strains of bacillus cereus were analyzed by pulsed-field gel electrophoresis (pfge) and compared with 12 bacillus thuringiensis strains. in addition, the 36 strains were examined for variation in 15 chromosomal genes encoding enzymes (by multilocus enzyme electrophoresis [mee]). the genome of each strain had a distinct noti restriction enzyme digestion profile by pfge, and the 36 strains could be assigned to 27 multilocus genotypes by mee. however, neither pfge nor mee analysis could ... | 1994 | 16349267 |
| determination and distribution of cry-type genes of bacillus thuringiensis isolates from taiwan. | using pcr with a set of specific oligonucleotide primers to detect cryi-type genes, we were able to screen the cry-type genes of 225 bacillus thuringiensis soil isolates from taiwan without much cost in time or labor. some combinations of cry genes (the cry-type profile) in a single isolate were unique. we identified five distinct profiles of crystal genes from the b. thuringiensis soil isolates from taiwan. the cry genes included cryia(a), cryia(b), cryia(c), cryic, cryid, and cryiv. interestin ... | 1994 | 16349324 |
| removal of adsorbed toxin fragments that modify bacillus thuringiensis cryic delta-endotoxin iodination and binding by sodium dodecyl sulfate treatment and renaturation. | we report that 10- and 25-kda toxin fragments adhere to cryic prepared from bacillus thuringiensis insecticidal crystals, block iodination, and alter membrane binding. there is no apparent affect on cryic toxicity against spodoptera exigua. associated peptides remained bound to cryic in the presence of 50 mm dithiothreitol or 6 m urea. a novel detergent-renaturation procedure was developed for the purification of b. thuringiensis cryic toxin. sodium dodecyl sulfate (sds) treatment followed by ge ... | 1994 | 16349357 |
| binding of insecticidal crystal proteins of bacillus thuringiensis to the midgut brush border of the cabbage looper, trichoplusia ni (hübner) (lepidoptera: noctuidae), and selection for resistance to one of the crystal proteins. | the susceptibility of trichoplusia ni larvae to several bacillus thuringiensis insecticidal crystal proteins (icps) was tested. neonatal larvae proved to be susceptible to solubilized trypsin-treated cryia(a), cryia(b), and cryia(c) (50% lethal concentrations [lc(50)s], 570, 480, and 320 ng/cm, respectively) but showed little susceptibility to cryib and cryid (lc(50)s, 5,640 and 2,530 ng/cm, respectively). the toxicity of icps was correlated to binding to the epithelial brush border of the midgu ... | 1994 | 16349420 |
| comparison of disulfide contents and solubility at alkaline ph of insecticidal and noninsecticidal bacillus thuringiensis protein crystals. | we compared two insecticidal and eight noninsecticidal soil isolates of bacillus thuringiensis with regard to the solubility of their proteinaceous crystals at alkaline ph values. the protein disulfide contents of the insecticidal and noninsecticidal crystals were equivalent. however, six of the noninsecticidal crystals were soluble only at ph values of >/=12. this lack of solubility contributed to their lack of toxicity. one crystal type which was soluble only at ph >/=12 (strain shp 1-12) did ... | 1994 | 16349421 |
| cross-resistance to bacillus thuringiensis toxin cryif in the diamondback moth (plutella xylostella). | selection with bacillus thuringiensis subsp. kurstaki, which contains cryia and cryii toxins, caused a >200-fold cross-resistance to cryif toxin from b. thuringiensis subsp. aizawai in the diamondback moth, plutella xylostella. cryie was not toxic, but cryib was highly toxic to both selected and unselected larvae. the results show that extremely high levels of cross-resistance can be conferred across classes of cryi toxins of b. thuringiensis. | 1994 | 16349471 |
| synergism between bacillus thuringiensis spores and toxins against resistant and susceptible diamondback moths (plutella xylostella). | we studied the effects of combinations of bacillus thuringiensis spores and toxins on the mortality of diamondback moth (plutella xylostella) larvae in leaf residue bioassays. spores of b. thuringiensis subsp. kurstaki increased the toxicity of crystals of b. thuringiensis subsp. kurstaki to both resistant and susceptible larvae. for b. thuringiensis subsp. kurstaki, resistance ratios were 1,200 for a spore-crystal mixture and 56,000 for crystals without spores. treatment of a spore-crystal form ... | 1998 | 16349543 |
| changes in permeability of brush border membrane vesicles from spodoptera littoralis midgut induced by insecticidal crystal proteins from bacillus thuringiensis. | bacillus thuringiensis insecticidal crystal proteins (icps) are thought to induce pore formation in midgut cell membranes of susceptible insects. cry1ca, which is significantly active in spodoptera littoralis, made brush border membrane vesicles permeable to kcl (osmotic swelling was monitored by the light scattering technique); the marginally active icps cry1aa, cry1ab, and cry1ac did not. | 1998 | 16349555 |
| asn183 in alpha5 is essential for oligomerisation and toxicity of the bacillus thuringiensis cry4ba toxin. | the proposed toxicity mechanism of the bacillus thuringiensis cry insecticidal proteins involves membrane penetration and lytic pore formation of the alpha4-alpha5 hairpins in the target larval midgut cell membranes. in this study, alanine substitutions of selected polar residues (tyr(178), gln(180), asn(183), asn(185), and asn(195)) in the hydrophobic helix-alpha5 of the cry4ba mosquito-larvicidal protein were initially conducted via pcr-based directed mutagenesis. upon iptg induction, all the ... | 2006 | 16356469 |
| mucosal and systemic adjuvant effects of cholera toxin and cry1ac protoxin on the specific antibody response to hiv-1 c4/v3 peptides are different and depend on the antigen co-administered. | evidence from several sources support the assertion that cholera toxin (ct) is a potent immunogen and mucosal adjuvant; however there are also reports showing its lack of adjuvanticity against some antigens. cry1ac protoxin also exerts adjuvant effects in the antibody responses to proteins and polysaccharides but its adjuvanticity with regard to peptide vaccines had not been tested. to probe whether the adjuvant effects of these proteins varied depending on the antigen co-administered, we evalua ... | 2005 | 16359236 |
| in situ studies on the time-dependent degradation of recombinant corn dna and protein in the bovine rumen. | an in situ technique was adopted to investigate the time-dependent ruminal degradation of chloroplast compared with recombinant dna of bt176 corn using conventional and quantitative pcr assays. in parallel, the cry1ab protein content and fragment sizes were determined by elisa and immunoblotting techniques. triplicate nylon bags filled with 5 g of each substrate (whole-plant isogenic, whole-plant transgenic, ensiled isogenic, and ensiled transgenic corn) were positioned within the rumen of 5 rum ... | 2006 | 16361500 |
| improved elisa method for screening human antigen-specific ige and its application for monitoring specific ige for novel proteins in genetically modified foods. | for monitoring the occurrence of ige antibody specific for novel proteins in genetically modified (gm) foods, elisa is the most convenient method. the levels of ige specific for recombinant proteins, phosphinothricin-n-acetyltransferase (pat), cp4-epsps, and cry9c were determined by elisa using the sera from patients allergic to known allergens. ovalbumin (ova) and ova-positive patient sera were used as positive control. in the elisa, 20-fold-diluted sera tested were mostly negative for the spec ... | 2006 | 16364525 |
| atomic force microscopy of bacillus spore surface morphology. | bacillus spore surface morphology was imaged with atomic force microscopy (afm) to determine if characteristic surface features could be used to distinguish between four closely related species; bacillus anthracis sterne strain, bacillus thuringiensis var. kurstaki, bacillus cereus strain 569, and bacillus globigii var. niger. afm surface height images showed an irregular topography across the curved upper surface of the spores. phase images showed a superficial grain structure with different le ... | 2006 | 16376084 |
| bacteria isolated from the different developmental stages and larval organs of the obligate parasitic fly, wohlfahrtia magnifica (diptera: sarcophagidae). | wohlfahrtia magnifica (diptera: sarcophagidae) is the major myiasis-causing fly species in the whole of eurasia for most important domestic animals. the aim of the present work was to obtain data on the culturable bacteria isolated under aerobic conditions from this fly: bacteria were isolated from all developmental stages (larvae, pupa, and imago) of wohlfahrtia magnifica, and the third-stage larval organs were also sampled. to determine the possible antagonistic effects between the dominant ba ... | 2006 | 16382282 |
| the role of a conserved histidine-tyrosine interhelical interaction in the ion channel domain of delta-endotoxins from bacillus thuringiensis. | the delta-endotoxin proteins are produced by bacillus thuringiensis during the sporulation phase of its life cycle. these proteins exhibit insecticidal activity through receptor-mediated ion channel formation. the mode of action of these proteins requires the conversion of the protein from a water-soluble conformation to a membrane-inserted conformation. while there is x-ray structure information for the soluble protein, no detailed structure exists for the membrane-inserted protein. however, ba ... | 2006 | 16385471 |
| vegetative insecticidal protein (vip1ac) of bacillus thuringiensis hd201: evidence for oligomer and channel formation. | the binding component (vip1ac) of the adp-ribosylating vegetative insecticidal protein (vip) of bacillus thuringiensis hd201 was isolated from the supernatant of cell cultures. vip1ac protein solubilized at room temperature ran as oligomers on sds-page. these oligomers were not resistant to heating. mass spectroscopic analysis of this high molecular mass band identified it as vip1ac. the protein formed in artificial lipid bilayer membranes channels with two conductance states of about 350 and 70 ... | 2006 | 16388604 |
| influence of cry1ac toxin on mineralization and bioavailability of glyphosate in soil. | the impact of transgenic plants containing bacillus thuringiensis (bt) toxin on soil processes has received recent attention. in these studies, we examined the influence of the lepidopterean bt cry1ac toxin on mineralization and bioavailability of the herbicide glyphosate in two different soils. the addition of 0.25-1.0 microg g(-1) soil of purified cry1ac toxin did not significantly affect glyphosate mineralization and sorption in either a sandy loam or a sandy soil. in contrast, extractable gl ... | 2006 | 16390194 |
| a bacillus thuringiensis s-layer protein involved in toxicity against epilachna varivestis (coleoptera: coccinellidae). | the use of bacillus thuringiensis as a biopesticide is a viable alternative for insect control since the insecticidal cry proteins produced by these bacteria are highly specific; harmless to humans, vertebrates, and plants; and completely biodegradable. in addition to cry proteins, b. thuringiensis produces a number of extracellular compounds, including s-layer proteins (slp), that contribute to virulence. the s layer is an ordered structure representing a proteinaceous paracrystalline array whi ... | 2006 | 16391064 |
| use of bacillus thuringiensis toxins for control of the cotton pest earias insulana (boisd.) (lepidoptera: noctuidae). | thirteen of the most common lepidopteran-specific cry proteins of bacillus thuringiensis have been tested for their efficacy against newly hatched larvae of two populations of the spiny bollworm, earias insulana. at a concentration of 100 microg of toxin per milliliter of artificial diet, six cry toxins (cry1ca, cry1ea, cry1fa, cry1ja, cry2aa, and cry2ab) were not toxic at all. cry1aa, cry1ja, and cry2aa did not cause mortality but caused significant inhibition of growth. the other cry toxins (c ... | 2006 | 16391075 |
| protease inhibitors fail to prevent pore formation by the activated bacillus thuringiensis toxin cry1aa in insect brush border membrane vesicles. | to investigate whether membrane proteases are involved in the activity of bacillus thuringiensis insecticidal toxins, the rate of pore formation by trypsin-activated cry1aa was monitored in the presence of a variety of protease inhibitors with manduca sexta midgut brush border membrane vesicles and by a light-scattering assay. most of the inhibitors tested had no effect on the pore-forming ability of the toxin. however, phenylmethylsulfonyl fluoride, a serine protease inhibitor, promoted pore fo ... | 2006 | 16391085 |
| role of tryptophan residues in toxicity of cry1ab toxin from bacillus thuringiensis. | bacillus thuringiensis produces insecticidal proteins (cry protoxins) during the sporulation phase as parasporal crystals. during intoxication, the cry protoxins must change from insoluble crystals into membrane-inserted toxins which form ionic pores. the structural changes of cry toxins during oligomerization and insertion into the membrane are still unknown. the cry1ab toxin has nine tryptophan residues; seven are located in domain i, the pore-forming domain, and two are located in domain ii, ... | 2006 | 16391132 |
| detection and identification of cry1i genes in bacillus thuringiensis using polymerase chain reaction and restriction fragment length polymorphism analysis. | a polymerase chain reaction-restriction fragment length polymorphism (pcr-rflp) method for detection and identification of cry1i genes from bacillus thuringiensis (bt) was established. based on the analysis of conserved regions of the cry1i genes, 2 oligonucleotide primers were designed to amplify a 665-bp fragment of the genes. the amplification products were digested with restriction endonuclease hinfi or with rsai in addition for specific detection of different variants from the known subclas ... | 2006 | 16392002 |
| nontoxic crystal protein from bacillus thuringiensis demonstrates a remarkable structural similarity to beta-pore-forming toxins. | 2006 | 16400649 | |
| field evidence for the exposure of ground beetles to cry1ab from transgenic corn. | non-target organisms associated with the soil might be adversely affected by exposure to the crylab protein from bacillus thuringiensis (bt) in transgenic corn (zea mays l.). to check for such exposure, we used elisa to test for cry1ab in ground beetles collected live from fields with bt corn residues and bt corn (bt/bt), bt corn residues and non-bt crops (bt/non-bt), or non-bt corn residues and non-bt crops (non-bt/non-bt). in fields with bt corn residues (bt/bt and bt/non-bt), cry1ab was prese ... | 2005 | 16402666 |
| transgenic crops expressing bacillus thuringiensis toxins and biological control. | the area devoted to growing transgenic plants expressing insecticidal cry proteins derived from bacillus thuringiensis (bt) is increasing worldwide. a major concern with the adoption of bt crops is their potential impact on nontarget organisms including biological control organisms. regulatory frameworks should advocate a step-wise (tiered) approach to assess possible nontarget effects of bt crops. laboratory and glasshouse studies have revealed effects on natural enemies only when bt-susceptibl ... | 2006 | 16404399 |
| mass spectrometric sequencing of endotoxin proteins of bacillus thuringiensis ssp. konkukian extracted from polyacrylamide gels. | the amino acid sequences of the crystal proteins of bacillus thuringiensis ssp. konkukian strain hl-47 are unknown. we used 1-d denaturing polyacrylamide electrophoresis, nano-esi-q-tof-ms, and protein database searching to analyze these proteins. on sds-page gels, a preparation of purified crystal proteins exhibited 110, 102, 76, 55, 37, and 30 kda protein bands. immunoblotting of the gel with antiserum raised to this preparation revealed that four crystal proteins, of 110, 102, 55, and 37 kda, ... | 2006 | 16404726 |
| a novel index for analysing the response of a microbial culture to changes in the environmental variables during cultivation. | to analyse the sensitivity of a microbial culture to variations in the cultivation conditions by using the motile intensity of the cells. | 2006 | 16405701 |
| lack of cross-reactivity between the bacillus thuringiensis derived protein cry1f in maize grain and dust mite der p7 protein with human sera positive for der p7-ige. | cry1f protein, derived from bacillus thuringiensis, is effective at controlling lepidopteran pests and a synthetic cry1f transgene was transferred into maize. for the safety assessment of genetically modified food crops, the allergenic potential of the introduced novel trait(s) is evaluated. because no single parameter is currently predictive of allergic potential, a 'weight of evidence' approach has been proposed. as part of this assessment, the amino acid (aa) sequence of the cry1f protein was ... | 2006 | 16406630 |
| effect of bacillus thuringiensis subsp. israelensis and neonicotinoid insecticides on the fungus gnat bradysia sp nr. coprophila (lintner) (diptera: sciaridae). | the soil bacterium bacillus thuringiensis berliner subsp. israelensis (bti), the neonicotinoid insecticides dinotefuran, imidacloprid, thiamethoxam and clothianidin and the insect growth regulator pyriproxyfen were evaluated to determine their efficacy against the larval stages of the fungus gnat bradysia sp nr. coprophila (lintner) in the laboratory. treatments were applied as a drench to the growing medium in polypropylene deli containers. the bti treatments had no effect on either instar test ... | 2006 | 16408320 |
| regeneration of sugarcane elite breeding lines and engineering of stem borer resistance. | five elite sugarcane breeding lines were tested for efficiency in embryogenesis and plant regeneration. all of them produced regenerative embryogenic calli but with varied efficiencies. to engineer strongly insect-resistant sugarcanes, the gc content of a truncated cry1ac gene, which encodes the active region of cry1ac insecticidal delta-endotoxin, was increased from the original 37.4 to 47.5% following the sugarcane codon usage pattern. the synthetic cry1ac gene (s-cry1ac) was placed under the ... | 2006 | 16408322 |
| a new black fly isolate of bacillus thuringiensis autoagglutinating strain highly toxic to simulium pertinax (kollar) (diptera, simuliidae) larvae. | formulations containing the entomopathogenic bacillus thuringiensis serovar israelensis strain ips-82 has been widely applied for mosquito control around the world. strain ips-82 is highly active against aedes aegypti but less active against other well-known vectors such as culex quinquefasciatus and simulium spp. larvae. eighteen strains of b. thuringiensis were isolated from simulium pertinax larvae naturally occurring in rivers of southeast brazil with one demonstrating special toxic effects. ... | 2006 | 16410971 |
| evidence of oral toxicity of photorhabdus temperata strain k122 against prays oleae and its improvement by heterologous expression of bacillus thuringiensis cry1aa and cry1ia genes. | photorhabdus temperata strain k122 exhibited oral toxicity against prays oleae with an lc50 of 58.1 x 10(6) cells ml(-1). recombinant p. temperata strains expressing the cry1aa and/or cry1ia genes of bacillus thuringiensis have been constructed. the two cry genes, encoding delta-endotoxins, were placed under the control of the lac promoter and iptg dependent expression in p. temperata was demonstrated. the presence of the cry genes in k122 resulted in a clear improvement of oral toxicity. this i ... | 2006 | 16413572 |
| [study on identification, colonization and reorganization of rice endophytic bacteria]. | endophytic sr-15, sr-25 and sl-37 strains screened from rice hybrid d you 527 in sichuan were analyzed. through penetration and microscopic test, the strains were found be mainly located in the cell gap, vacuole and cytoplasm. puc18 transferring and eric-pcr showed that the recombination strain sr-15 could grow in the plant stably. the strain was identified as bacillus halmapalus based on its chemical components of cell wall, physiological and biochemical characters. it was also shown that the s ... | 2005 | 16416963 |
| bacillus thuringiensis protein production, signal transduction, and insect control in chemically inducible pr-1a/cry1ab broccoli plants. | in an effort to develop a chemically inducible system for insect management, we studied production of cry1ab bacillus thuringiensis (bt) protein and control of the diamondback moth (dbm), plutella xylostella l., in inducer-treated and untreated tissues of a broccoli line transformed with a pr-1a/cry1ab expression cassette. spraying leaves of these plants with the inducer acibenzolar-s-methyl (= 1,2,3 benzothiadiazole-7-thiocarboxylic acid-s-methyl-ester) (asm) triggered expression of the cry1ab ... | 2006 | 16418860 |
| typical three-domain cry proteins of bacillus thuringiensis strain a1462 exhibit cytocidal activity on limited human cancer cells. | bacillus thuringiensis strain a1462 produced two parasporal inclusion proteins with a molecular mass of 88 kda that were converted to 64-kda toxins when activated by proteinase k digestion. both toxins exhibited strong cytocidal activity against two human cancer cell lines, hl60 (myeloid leukemia cells) and hepg2 (liver cancer cells), while low or no toxicities were observed against 11 human and three mammalian cell lines, including four non-cancer cell lines. the cytotoxicity of both toxins on ... | 2005 | 16428294 |
| proteomic analysis of the bacteriocin thuricin 17 produced by bacillus thuringiensis neb17. | thuricin 17 is a recently discovered bacteriocin produced by bacillus thuringiensis neb17. the objective of this work was to conduct a proteomic analysis of this bacteriocin. the partial n- and c-terminal amino-acid sequences of thuricin 17 have now been determined using the edman degradation and matrix-assisted laser desorption ionization-quadrapole time of flight mass spectrometry (ms)/ms. a hydrophobic cluster analysis indicates that thuricin 17 contains a hydrophobic region, potentially corr ... | 2006 | 16436058 |
| redesigning bacillus thuringiensis cry1aa toxin into a mosquito toxin. | the bacillus thuringiensis crystal protein cry1aa is normally selectively active to caterpillar larvae. through rational design, toxicity (microg/ml) to the mosquito culex pipiens was introduced by selected deletions and substitutions of the loop residues of domain ii. toxicity to its natural target manduca sexta was concomitantly abolished. the successful grafting of the alternate mosquito toxicity onto the original lepidopteran cry1aa toxin demonstrates the possibility of designing and enginee ... | 2006 | 16436453 |
| vegetative insecticidal protein enhancing the toxicity of bacillus thuringiensis subsp kurstaki against spodoptera exigua. | the objective of this work was to enhance the insecticidal activity or widen the pesticidal spectrum of a commercial bacillus thuringiensis strain ybt1520. | 2006 | 16441373 |
| purification and characterization of a chimeric cry1f delta-endotoxin expressed in transgenic cotton plants. | cotton plants were genetically modified through the introduction of a synthetic gene that encodes a bacillus thuringiensis insecticidal protoxin referred to as cry1f(synpro). this protoxin is a chimeric, full-length delta-endotoxin of 130 kda, comprised of the core toxin of cry1fa2 protein and parts of the nontoxic portions of cry1ca3 and cry1ab1 proteins, all of which originated from bacillus thuringiensis. the cry1f(synpro) expressed in cotton plants confers resistance to lepidopteran pests. t ... | 2006 | 16448190 |
| fate of the cry1ab protein from bt-maize mon810 silage in biogas production facilities. | biogas plants fuelled with renewable sources of energy are a sustainable means for power generation. in areas with high infestation levels with the european corn borer, ostrinia nubilalis (hbn.), it is likely that transgenic bt-maize will be fed into agricultural biogas plants. the fate of the entomotoxic protein cry1ab from mon810 maize was therefore investigated in silage and biogas production-related materials in the utilization chains of two farm-scale biogas plants. the cry1ab content in si ... | 2006 | 16448198 |
| assessment of populus wood chemistry following the introduction of a bt toxin gene. | unintended changes in plant physiology, anatomy and metabolism as a result of genetic engineering are a concern as more transgenic plants are commercially deployed in the ecosystem. we compared the cell wall chemical composition of three populus lines (populus trichocarpa torr. & a. gray x populus trichocarpa bartr. ex marsh., populus trichocarpa x populus nigra l. and populus deltoides x populus nigra) genetically modified to express the cry3a or cry3b2 protein of bacillus thuringiensis (bt) wi ... | 2006 | 16452069 |
| a novel 96-kda aminopeptidase localized on epithelial cell membranes of bombyx mori midgut, which binds to cry1ac toxin of bacillus thuringiensis. | proteins in the brush border membrane (bbm) of the midgut binding to the insecticidal cry1ac toxin from bacillus thuringiensis were investigated to examine the lower sensitivity of bombyx mori to cry1ac, and new aminopeptidase n that bound to cry1ac was discovered. deae chromatography of triton x-100-soluble bbm proteins from the midgut revealed 96-kda aminopeptidase that bound to cry1ac. the enzyme was purified to homogeneity and estimated to be a 96.4-kda molecule on a silver-stained sds-page ... | 2006 | 16452310 |
| cry1ab protein from bt transgenic rice does not residue in rhizosphere soil. | expression of cry1ab protein in bt transgenic rice (kmd) and its residue in the rhizosphere soil during the whole growth in field, as well as degradation of the protein from kmd straw in five soils under laboratory incubation were studied. the residue of cry1ab protein in kmd rhizosphere soil was undetectable (below the limit of 0.5 ng/g air-dried soil). the cry1ab protein contents in the shoot and root of kmd were 3.23-8.22 and 0.68-0.89 microg/g (fresh weight), respectively. the half-lives of ... | 2006 | 16459002 |
| [development of transgenic oilseed plants resistant to glyphosate and insects]. | in this study, the aroa-m12 gene encoding bacterial 5-enolpyruvylshikimate-3-phosphate synthase (epsps) and the btslm recombinant gene encoding bacillus thuringiensis (bt) toxin gene were introduced into a brassica napus variety, xiangyou no. 15, via agrobacterium-mediated transformation using glyphosate as a selectable agent. pcr amplification and southern blot analyses of t0 transgenic plants showed that the alien genes were transferred and integrated stably into the genome of xiangyou no. 15. ... | 2005 | 16459658 |
| strategy for identification of bacillus cereus and bacillus thuringiensis strains closely related to bacillus anthracis. | bacillus cereus strains that are genetically closely related to b. anthracis can display anthrax-like virulence traits (a. r. hoffmaster et al., proc. natl. acad. sci. usa 101:8449-8454, 2004). hence, approaches that rapidly identify these "near neighbors" are of great interest for the study of b. anthracis virulence mechanisms, as well as to prevent the use of such strains for b. anthracis-based bioweapon development. here, a strategy is proposed for the identification of near neighbors of b. a ... | 2006 | 16461679 |
| multiple-locus sequence typing analysis of bacillus cereus and bacillus thuringiensis reveals separate clustering and a distinct population structure of psychrotrophic strains. | we used multilocus sequence typing (mlst) to characterize phylogenetic relationships for a collection of bacillus cereus group strains isolated from forest soil in the paris area during a mild winter. this collection contains multiple strains isolated from the same soil sample and strains isolated from samples from different sites. we characterized 115 strains of this collection and 19 other strains based on the sequences of the clpc, dinb, gdpd, panc, purf, and yhfl loci. the number of alleles ... | 2006 | 16461712 |
| lack of detrimental effects of bacillus thuringiensis cry toxins on the insect predator chrysoperla carnea: a toxicological, histopathological, and biochemical analysis. | the effect of cry proteins of bacillus thuringiensis on the green lacewing (chrysoperla carnea) was studied by using a holistic approach which consisted of independent, complementary experimental strategies. tritrophic experiments were performed, in which lacewing larvae were fed helicoverpa armigera larvae reared on cry1ac, cry1ab, or cry2ab toxins. in complementary experiments, a predetermined amount of purified cry1ac was directly fed to lacewing larvae. in both experiments no effects on prey ... | 2006 | 16461715 |
| unusual envelopes associated with parasporal inclusions of a mosquitocidal bacillus thuringiensis serovar fukuokaensis isolate. | a mosquitocidal soil isolate of bacillus thuringiensis serovar fukuokaensis (h3ade) produced spherical parasporal inclusions measuring 0.6-0.7 microm in diameter. inclusion matrix was homogeneous substance surrounded by a thick, highly electron-dense envelope 30-50 nm in thickness. the envelopes were associated with both intracellular and extracellular inclusions. densely woven network was the inner structure of the envelope. often, inclusions had round-shaped, enveloped small protrusions on the ... | 2006 | 16463320 |
| sequence variation in trypsin- and chymotrypsin-like cdnas from the midgut of ostrinia nubilalis: methods for allelic differentiation of candidate bacillus thuringiensis resistance genes. | midgut expressed alkaline serine proteases of lepidoptera function in conversion of bacillus thuringiensis (bt) protoxin to active toxin, and reduced level of transcript t23 is associated with ostrinia nubilalis resistance to dipel bt formulations. three groups of trypsin- (ont25, ont23, and ont3) and two chymotrypsin-like (onc1 and onc2) cdnas were isolated from o. nubilalis midgut tissue. intraspecific groupings are based on cdna similarity and peptide phylogeny. derived serine proteases showe ... | 2006 | 16469064 |
| six years after the commercial introduction of bt maize in spain: field evaluation, impact and future prospects. | we carried out a 6-year-field evaluation to assess potential hazards of growing compa, a transgenic bt maize variety based on the transformation event cg 00256-176. two categories of hazards were investigated: the potential of the target corn borer sesamia nonagrioides to evolve resistance to bt maize and effects on non-target organisms. in order to address the first hazard, dispersal capacity of the corn borer was measured and our results indicated that larvae move to plants other than those on ... | 2006 | 16475005 |
| a quantitative assay for linking microbial community function and structure of a naphthalene-degrading microbial consortium. | a comprehensive culture-independent assay, called q-fast, was developed for concurrent identification and quantification of active microorganisms involved a specific function in a given microbial community. the development of q-fast was achieved by integrating the concept of stable isotope probing technique into a new quantitative fingerprinting assay called real-time-t-rflp for microbial community structure analysis. the q-fast was successfully validated by using a three-member artificial micro ... | 2005 | 16475342 |
| fiber-optic microsphere-based arrays for multiplexed biological warfare agent detection. | we report a multiplexed high-density dna array capable of rapid, sensitive, and reliable identification of potential biological warfare agents. an optical fiber bundle containing 6000 individual 3.1-mum-diameter fibers was chemically etched to yield microwells and used as the substrate for the array. eighteen different 50-mer single-stranded dna probes were covalently attached to 3.1-mum microspheres. probe sequences were designed for bacillus anthracis, yersinia pestis, francisella tularensis, ... | 2006 | 16478092 |
| a novel bacteriocin, thuricin 17, produced by plant growth promoting rhizobacteria strain bacillus thuringiensis neb17: isolation and classification. | the aim of this study was to identify and characterize a compound produced by the plant growth promoting bacterium, bacillus thuringiensis non-bradyrhizobium endophytic bacterium 17. | 2006 | 16478494 |
| discovery and characterization of sip1a: a novel secreted protein from bacillus thuringiensis with activity against coleopteran larvae. | bioassay screening of bacillus thuringiensis culture supernatants identified strain eg2158 as having larvicidal activity against colorado potato beetle (leptinotarsa decemlineata) larvae. ion-exchange fractionation of the eg2158 culture supernatant resulted in the identification of a protein designated sip1a (secreted insecticidal protein) of approximately 38 kda having activity against colorado potato beetle (cpb). an oligonucleotide probe based on the n-terminal sequence of the purified sip1a ... | 2006 | 16489451 |
| toxin-binding proteins from midgut epithelium membranes of anopheles stephensi larvae. | proteins of 65 and 57 kd were isolated from the apical membranes of midgut epithelium of anopheles stephensi larvae by affinity chromatography. these proteins can specifically bind endotoxin cry11a and activate toxin cry4b (cry4b-tox) under conditions of ligand blotting, and both cry proteins compete for this binding. at least in the case of cry4b-tox, the binding with 65 and 57 kd proteins is reversible. the ability of the products of limited proteolysis of cry11a and cry4b to bind the 65 and 5 ... | 2006 | 16489916 |
| development and validation of a sensitive and fast chemiluminescent enzyme immunoassay for the detection of genetically modified maize. | proteins from the cry 1 family, in particular cry 1ab, are commonly expressed in genetically modified bt maize in order to control chewing insect pests. a sensitive chemiluminescent sandwich enzyme immunoassay for the detection of cry1ab protein from genetically modified bt maize has been developed and validated. a cry1ab protein-specific antibody was immobilized on 96- or 384-well microtiter plates in order to capture the cry1ab toxin in the sample; the bound toxin was then detected by employin ... | 2006 | 16491341 |
| [cloning and functional analysis of the stable plasmid pbmb175 in bacillus thuringiensis subsp. tenebrionis strains ybt-1765]. | a 15.2 kb plasmid pbmb175 from bacillus thuringiensis subsp. tenebrionis strains ybt-1765 was cloned and the restriction map was constructed. the mini-replicating region of pbmb175 was located in a 1151 bp fragment by functional analysis. the sequence of a 4152 bp fragment which contained the mini-replicating region was analyzed and results showed that the fragment had three potential open reading frames (orf1, orf2 and orf3). sequence comparison and homology search revealed that orf1 (767aa) ha ... | 2005 | 16496686 |
| [co-expression of crystal protein gene cry26aa and cry28aa has an ability to form parasporal crystal inside exosporium in bacillus thuringiensis subsp. finitimus]. | parasporal crystal in bacillus thuringiensis subsp. finitimus t02 forms within the exosporium and remains attached to the spore after mother cell lysis, which leads to spore-crystal connection. according to the crystal protein gene sequence in b. thuringiensis subsp. finitimus, cry26 and cry28 were cloned from strain t02 by pcr amplification and transformed into the crystal negative bacillus thuringiensis strain bmb171 by shuttle vectors, alone or in combination together. crystal can be observed ... | 2005 | 16496711 |
| occurrence and persistence of bacillus thuringiensis (bt) and transgenic bt corn cry1ab gene from an aquatic environment. | genetically modified corn crops and suspensions of bacillus thuringiensis (bt) are currently used to control pest infestations of insects of the lepidoptera family. for this purpose, the cry1ab gene coding for protein delta-endotoxin derived from b. thuringiensis kurstaki (btk), which is highly toxic to these insects, was inserted and expressed in corn. the aims of this study were to examine the occurrence and persistence of the cry1ab gene from btk and bt corn in aquatic environments near field ... | 2007 | 16499967 |
| toxicity of bacillus thuringiensis var. israelensis formulations, spinosad, and selected synthetic insecticides to chironomus tepperi larvae. | three bacillus thuringiensis var. israelensis (bti) formulations, the bacterial metabolite spinosad, and 7 synthetic insecticides were bioassayed against 4th instars of chironomus tepperi, a serious pest of rice in southern australia. the bti formulations returned 48-h product median lethal concentration (lc50) values (25 < or = 1 degrees c) of between 0.59 mg/liter (vectobac water-dispersible granule [wdg], 3,000 international toxic units [itu]/mg) and 2.15 mg/liter (teknar suspension concentra ... | 2005 | 16506570 |
| trial of bacillus thuringiensis israelensis, a mosquito larvicide, against porcellionides pruinosus, a terrestrial isopod. | woodlice, porcellionides pruinosus, were not killed when exposed to granular bacillus thuringiensis israelensis. mortality was observed when woodlice received a topical application of the highest concentration of liquid bti, but not at lower concentrations, nor when exposed via contaminated food or contaminated substrates. | 2005 | 16506582 |
| [expression of the bacterial gene cspd in tobacco plants increases their resistance to fungal and viral pathogens]. | low molecular (7.2 kd) cold shock protein d (cspd) from bacillus thuringiensis was isolated in our laboratory in the late 1990s it was shown that cspd induced nonspecific resistance in plants to viral and fungal phytopathogens. it was suggested to explore the opportunity to express the gene of this elicitor in tobacco plant and evaluate the resistance ofthe transgenic plants to various pathogens. several transgenic tobacco lines were obtained. enhanced resistance of the transgenic plants was con ... | 2006 | 16512609 |
| cereulide synthetase gene cluster from emetic bacillus cereus: structure and location on a mega virulence plasmid related to bacillus anthracis toxin plasmid pxo1. | cereulide, a depsipeptide structurally related to valinomycin, is responsible for the emetic type of gastrointestinal disease caused by bacillus cereus. recently, it has been shown that this toxin is produced by a nonribosomal peptide synthetase (nrps), but its exact genetic organization and biochemical synthesis is unknown. | 2006 | 16512902 |
| [potential effects of bt transgenic rice on soil micro-ecosystem]. | with the increasing commercial use of genetically modified crops (gmcs), it is quite important to assess their potential ecological risk. the likelihood of genes dispersal from gmcs to related wild species, the tolerance of insects to insect-resistant gmcs, and the potential impact of gmcs on biodiversity have been extensively investigated. this article reviewed the potential ecological risk assessment of transgenic bt rice-expressed products, including the persistence characteristics of bt inse ... | 2005 | 16515209 |
| efficient centrifugal recovery of bacillus thuringiensis biopesticides from fermented wastewater and wastewater sludge. | studies were conducted on harvesting of bacillus thuringiensis (bt)-based biopesticides from fermented broths of starch industry wastewater (siw), wastewater sludge (raw and hydrolyzed-nh and th, respectively) and semi-synthetic soyameal to enhance entomotoxicity (tx) by centrifugation. pertinent factors influencing tx, solids concentration, ph, temperature and centrifugal force were investigated. the centrifugate solids concentration beyond 100 g/l did not enhance tx, instead caused pellet form ... | 2006 | 16515801 |
| conjugal transfer of a toxin-coding megaplasmid from bacillus thuringiensis subsp. israelensis to mosquitocidal strains of bacillus sphaericus. | both bacillus sphaericus and bacillus thuringiensis subsp. israelensis produce mosquitocidal toxins during sporulation and are extensively used in the field for control of mosquito populations. all the known toxins of the latter organism are known to be encoded on a large plasmid, pbtoxis. in an attempt to combine the best properties of the two bacteria, an erythromycin resistance-marked pbtoxis plasmid was transferred to b. sphaericus by a mating technique. the resulting transconjugant bacteria ... | 2006 | 16517620 |
| transcriptional analysis of the toxin-coding plasmid pbtoxis from bacillus thuringiensis subsp. israelensis. | in bacillus thuringiensis subsp. israelensis all of the insecticidal toxins are encoded on a single, large plasmid, pbtoxis. sequencing of this plasmid revealed 125 potential coding sequences, many of which have predicted functions in gene regulation and physiological processes, such as germination. as a first step in understanding the possible role of pbtoxis in its host bacterium, a survey of the transcription of genes with predicted functions was carried out. whereas many coding sequences, in ... | 2006 | 16517621 |
| the phytopathogen dickeya dadantii (erwinia chrysanthemi 3937) is a pathogen of the pea aphid. | dickeya dadantii (erwinia chrysanthemi) is a phytopathogenic bacterium causing soft rot diseases on many crops. the sequencing of its genome identified four genes encoding homologues of the cyt family of insecticidal toxins from bacillus thuringiensis, which are not present in the close relative pectobacterium carotovorum subsp. atrosepticum. the pathogenicity of d. dadantii was tested on the pea aphid acyrthosiphon pisum, and the bacterium was shown to be highly virulent for this insect, either ... | 2006 | 16517643 |
| response of aedes aegypti (diptera: culicidae) larvae to three xenobiotic exposures: larval tolerance and detoxifying enzyme activities. | the ability of mosquito larvae to tolerate toxic compounds (temephos, bacillus thuringiensis var. israelensis, toxic vegetable leaf litter) was examined on a laboratory larval strain of aedes aegypti l. bioassays and detoxifying enzyme activity measurements were performed to compare tolerance/resistance capacities. the possibility of a functional plasticity of detoxifying equipment was investigated through experimental determination of the inductive effect of each xenobiotic within a given gener ... | 2006 | 16519308 |
| behavioural responses and changes in biology of rice leaffolder following treatment with a combination of bacterial toxins and botanical insecticides. | ingestion of the bacterial toxins bacillus thuringiensis (berliner) sub sp kurstaki, neem seed kernel extract and vitex negundo l. (lamiales:verbenaceae) leaf extract to the rice leaffolder (rlf), cnaphalocrocis medinalis (guenée) (lepidoptera: pyralidae), resulted in altered leaf-folding behaviour and biology. in laboratory experiments, treatment with plant extracts and bacterial toxins suppressed leaf folding behaviour of c. medinalis. larvae fed lower doses moulted into progressive instars, b ... | 2006 | 16524618 |
| potato expressing beetle-specific bacillus thuringiensis cry3aa toxin reduces performance of a moth. | expression of the bacillus thuringiensis beetle-specific toxin cry3aa, which renders a genetically modified potato cultivar resistant to the colorado potato beetle leptinotarsa decemlineata, exerts a deleterious effect on the polyphagous moth spodoptera littoralis. the caterpillars of s. littoralis feed less and produce smaller pupae on the genetically modified cultivar (newleaf superior) than on the parental nontransgenic cultivar (superior). the conversion efficiencies of total dry matter, com ... | 2006 | 16525866 |
| activity of bacillus thuringiensis delta-endotoxins against codling moth (cydia pomonella l.) larvae. | solubilized protoxins of nine cry1 and one hybrid cry1 delta-endotoxin from bacillus thuringiensis were tested for their activity against larvae of the codling moth (cydia pomonella l). cry1da was the most toxic, followed by cry1ab, cry1ba, and cry1ac, while cry1aa, cry1fa, cry1ia, and sn19 were still less active. cry1ca and cry1cb showed no activity. in vitro trypsin activation increased activity of all eight active delta-endotoxins, and dramatically enhanced toxicity of hybrid sn19, cry1aa, cr ... | 2006 | 16530218 |
| dot blot enzyme-linked immunosorbent assay for monitoring the fate of insecticidal toxins from bacillus thuringiensis in soil. | the release of transgenic plants and microorganisms expressing truncated genes from bacillus thuringiensis that code for active insecticidal toxins rather than for the inactive protoxins could result in the accumulation of these active proteins in soil, especially when bound on clay minerals and other soil particles. to monitor the fate of these toxins in soil, a dot blot enzyme-linked immunosorbent assay (elisa) that detects free and particle-bound toxins from b. thuringiensis subsp. kurstaki a ... | 1995 | 16534931 |
| insecticidal activity of the toxins from bacillus thuringiensis subspecies kurstaki and tenebrionis adsorbed and bound on pure and soil clays. | the release of transgenic plants and microorganisms expressing truncated genes from various subspecies of bacillus thuringiensis that encode active insecticidal toxins rather than inactive protoxins could result in the accumulation of these active proteins in soil, especially when bound on clays and other soil particles. toxins from b. thuringiensis subsp. kurstaki and b. thuringiensis subsp. tenebrionis, either free or adsorbed at equilibrium or bound on pure clay minerals (montmorillonite or k ... | 1995 | 16535020 |
| development of bacillus thuringiensis cryic resistance by spodoptera exigua (hubner) (lepidoptera: noctuidae). | selection of resistance in spodoptera exigua (hubner) to an hd-1 spore-crystal mixture, cryic (hd-133) inclusion bodies, and trypsinized toxin from bacillus thuringiensis subsp. aizawai and b. thuringiensis subsp. entomocidus was attempted by using laboratory bioassays. no resistance to the hd-1 spore-crystal mixture could be achieved after 20 generations of selection. significant levels of resistance (11-fold) to cryic inclusion bodies expressed in escherichia coli were observed after seven gen ... | 1995 | 16535038 |
| binding of the cryivd toxin of bacillus thuringiensis subsp. israelensis to larval dipteran midgut proteins. | ligand-blotting experiments on dipteran brush border membrane vesicles (bbmvs) showed binding of cryivd toxin of bacillus thuringiensis subsp. israelensis to proteins of 148 kda in anopheles stephensi and of 78 kda in tipula oleracea, both species being susceptible to cryivd. binding of cryivd with bbmvs of a. stephensi resulted in a stronger signal than with bbmvs of t. oleracea. likewise, larvae of a. stephensi are 10,000-fold more susceptible to the cryivd toxin than are larvae of t. oleracea ... | 1995 | 16535074 |
| comparative analysis of the 16s to 23s ribosomal intergenic spacer sequences of bacillus thuringiensis strains and subspecies and of closely related species. | volume 61, no. 4, p. 1624, column 2, lines 38-41: the sentence should read "for example, at position 21, the g nucleotide (fig. 1) was present in all the isr b. thuringiensis subspecies except for b. thuringiensis subsp. tenebrionis (te4), which contained an a." page 1624, column 2, line 45: "position 62" should read "position 11." page 1624, column 2, line 47: "position 90" should read "position 39." page 1624, column 2, line 49: "position 83" should read "position 32." page 1625, column 1, lin ... | 1995 | 16535088 |
| isolation of multiple subspecies of bacillus thuringiensis from a population of the european sunflower moth, homoeosoma nebulella. | five subspecies of bacillus thuringiensis were isolated from dead and diseased larvae obtained from a laboratory colony of the european sunflower moth, homoeosoma nebulella. the subspecies isolated were b. thuringiensis subspp. thuringiensis (h 1a), kurstaki (h 3a3b3c), aizawai (h 7), morrisoni (h 8a8b), and thompsoni (h 12). most isolates produced typical bipyramidal crystals, but the b. thuringiensis subsp. thuringiensis isolate produced spherical crystals and the b. thuringiensis subsp. thomp ... | 1995 | 16535187 |
| toxicity of bacillus thuringiensis spore and crystal protein to resistant diamondback moth (plutella xylostella). | a colony of plutella xylostella from crucifer fields in florida was used in mortality bioassays with hd-1 spore, cryia(a), cryia(b), cryia(c), cryib, cryic, cryid, cryie, or cryiia. the data revealed high levels of field-evolved resistance to hd-1 spore and all cryia protoxins and no resistance to cryib, cryic, or cryid. cryie and cryiia were essentially not toxic. when hd-1 spore was combined 1:1 with protoxin and fed to susceptible larvae, spore synergized the activity of cryia and cryic 5- to ... | 1996 | 16535241 |
| characterization of a novel strain of bacillus thuringiensis. | bacillus thuringiensis is a well-known species of entomopathogenic bacteria that is widely used as a biopesticide against many insect pests. insecticidal proteins, coded for by genes located in plasmids, form typical parasporal, crystalline inclusions during sporulation. in this report, an unusual strain of b. thuringiensis subserovar oyamensis (lbit-113), isolated from living larvae of anopheles pseudopunctipennis in mexico, was characterized by its ultrastructure, the protein composition of it ... | 1996 | 16535294 |
| binding of bacillus thuringiensis cry1 toxins to the midgut brush border membrane vesicles of chilo suppressalis (lepidoptera: pyralidae): evidence of shared binding sites. | binding and competition among cry1aa, cry1ac, and cry1ba toxins were analyzed quantitatively in vitro by using (sup125)i-labeled activated toxins and brush border membrane vesicles isolated from chilo suppressalis larval midguts. the three toxins bound specifically to the midgut brush border membrane vesicles. direct binding experiments showed that cry1aa and cry1ba recognized a single class of binding sites with different affinities, whereas cry1aa recognized two classes of binding sites, one w ... | 1996 | 16535306 |
| binding of bacillus thuringiensis cry1 toxins to the midgut brush border membrane vesicles of chilo suppressalis (lepidoptera: pyralidae): evidence of shared binding sites. | volume 62, no. 5, p. 1544, abstract, line 4: "cry1aa" should read "cry1ac." [this corrects the article on p. 1544 in vol. 62.]. | 1996 | 16535392 |
| bacillus thuringiensis hd-73 spores have surface-localized cry1ac toxin: physiological and pathogenic consequences. | spores from cry(sup+) strains of bacillus thuringiensis bound fluorescein isothiocyanate-labeled antibodies specific for the 65-kda activated cry 1ac toxin, whereas spores from bacillus cereus and cry(sup-) strains of b. thuringiensis did not. the cry(sup+) spores could be activated for germination by alkaline conditions (ph 10.3), whereas cry(sup-) spores could not. once the surrounding exosporia had been removed or permeabilized, cry(sup+) spores were able to bind the toxin receptor(s) from in ... | 1996 | 16535421 |
| interaction between calcium ions and bacillus thuringiensis toxin activity against sf9 cells (spodoptera frugiperda, lepidoptera). | the effects of calcium ions and modulators of calcium movement on bacillus thuringiensis insecticidal protein toxicity were investigated with sf9 cells (spodoptera frugiperda, fall armyworm) by a new b. thuringiensis toxicity assay based on measurement of fluorescence of ethidium homodimer, a high-affinity dna stain. cryic toxicity was substantially stimulated by extracellular calcium in a dose-dependent way (in the millimolar range), while toxicity enhancement could not be replicated when calci ... | 1997 | 16535509 |
| binding of bacillus thuringiensis cry1ac toxin to aminopeptidase in susceptible and resistant diamondback moths (plutella xylostella). | bacillus thuringiensis cry1ac toxin bound to a 120-kda protein isolated from the brush border membranes of both susceptible and resistant larvae of plutella xylostella, the diamondback moth. the 120-kda protein was purified by cry1ac toxin affinity chromatography. like cry1ac-binding aminopeptidase n (ec 3.4.11.2) from other insects, this protein was eluted from the affinity column with 200 mm n-acetylgalactosamine. the purified protein had aminopeptidase activity and bound cry1ac toxin on ligan ... | 1997 | 16535536 |
| influence of exposure to single versus multiple toxins of bacillus thuringiensis subsp. israelensis on development of resistance in the mosquito culex quinquefasciatus (diptera: culicidae). | the impending widespread use of transgenic crop plants encoding a single insecticidal toxin protein of bacillus thuringiensis has focused attention on the perceived risk of rapid selection of resistance in target insects. we have used bacillus thuringiensis subsp. israelensis toxins as a model system and determined the speed and magnitude of evolution of resistance in colonies of the mosquito culex quinquefasciatus during selection for 28 consecutive generations with single or multiple toxins. t ... | 1997 | 16535542 |