Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| identification and partial characterization of tochicin, a bacteriocin offduced by bacillus thuringiensis subsp tochigiensis. | bacillus thuringiensis subsp tochigiensis hd868 was identified as a bacteriocin producer which exhibited a bactericidal effect against closely related species. this bacteriocin designated as tochicin, was partially purified by 75% ammonium sulfate precipitation followed by subsequent dialysis. this partially purified tochicin showed a narrow antibacterial spectrum of activity against most of 20 typical b. thuringiensis strains and a strain of b. cereus, but not against other bacteria and yeasts ... | 1997 | 9439004 |
| exploring hydrophobic sites in proteins with xenon or krypton. | x-ray diffraction is used to study the binding of xenon and krypton to a variety of crystallised proteins: porcine pancreatic elastase; subtilisin carlsberg from bacillus licheniformis; cutinase from fusarium solani; collagenase from hypoderma lineatum; hen egg lysozyme, the lipoamide dehydrogenase domain from the outer membrane protein p64k from neisseria meningitidis; urate-oxidase from aspergillus flavus, mosquitocidal delta-endotoxin cytb from bacillus thuringiensis and the ligand-binding do ... | 1998 | 9443341 |
| the heliothis virescens 170 kda aminopeptidase functions as "receptor a" by mediating specific bacillus thuringiensis cry1a delta-endotoxin binding and pore formation. | the relationship between bacillus thuringiensis cry1aa, cry1ab and cry1ac delta-endotoxin binding and pore formation was investigated using a purified 170 kda aminopeptidase n (apn) from heliothis virescens brush border membranes. aminopeptidases with molecular sizes of 110, 140 and 170 kda were eluted from a cry1ac toxin affinity column using n-acetylgalactosamine. the 140 kda aminopeptidase has a cross-reacting determinant typical of a cleaved glycosyl-phosphatidylinositol anchor. after mild b ... | 1997 | 9443374 |
| [sensitivity of larvae of the malaria mosquito anopheles messae with various inversion genotypes to the entomopathogenic bacteria bacillus thuringiensis israelensis as a function of dose]. | the influence of the entomopathogenic bacterium bacillus thuringiensis israelensis (bti) on the chromosomal composition of a natural population of fourth instar larvae of the malaria mosquito (anopheles messeae fall.) was investigated. the two doses used in the experiment yielded different death rates. a dose of 6.17 micrograms bti per 1 mg of host mass led to a death rate of 41.1 +/- 3.0%. the chromosomal composition of the population remained unchanged, but the proportion of xl11-2r11 females ... | 1997 | 9445817 |
| characterization of a new bacillus thuringiensis subsp. higo strain isolated from rice bran in korea | 1998 | 9446743 | |
| video imaging analysis of the plasma membrane permeabilizing effects of bacillus thuringiensis insecticidal toxins in sf9 cells. | the size and ionic selectivity of the pores formed by the insecticidal crystal protein cry1c from bacillus thuringiensis in the plasma membrane of sf9 cells, an established cell line derived from the fall armyworm spodoptera frugiperda, were analyzed with a video imaging technique. changes in the permeability of the membrane were estimated from the rate of osmotic swelling of the cells. in the presence of cry1c, which is toxic to sf9 cells, the permeability of the cell membrane to kcl and glucos ... | 1998 | 9459581 |
| bacillus popilliae cry18aa operon is transcribed by sigmae and sigmak forms of rna polymerase from a single initiation site. | bacillus popilliae is an obligate pathogen for larvae of the insect family scarabaeidae (coleoptera). it forms parasporal crystals upon sporulation. the gene cry18aa coding for the parasporal crystal protein and an upstream open reading frame, orf1, were previously isolated from b.popilliae. here we report an analysis of cry18aa transcription in bacillus thuringiensis. the only transcriptional start site of cry18aa was found 29 bp upstream of the open reading frame orf1, suggesting that orf1 and ... | 1998 | 9469839 |
| study on the flying height of aedes caspius and culex pipiens females in the po delta area, italy. | we have studied the vertical distribution of culicidae in the "ancona di bellocchio" protected area (regional park of the po delta, emilia-romagna, italy) by means of nonilluminated cdc traps baited with co2. traps were placed at heights of 1.5, 3, 4, and 5 m from the ground in open areas and at 1.5, 3, 4, 5, 6, and 7 m in wooded areas. we calculated the average flying height of the species caught, i.e., in order of decreasing flying height, culex pipiens linnaeus s.l., culex modestus ficalbi, c ... | 1997 | 9474562 |
| performance of ulv formulations (pesguard 102/vectobac 12as) against three mosquito species. | adulticidal and larvicidal performances of a water-based pyrethroid microemulsion pesguard ps 102 (ai d-allethrin and d-phenothrin, both at 5.0% w/w) and vectobac 12as, an aqua-suspension bacillus thuringiensis israelensis (b.t.i.) formulation (ai 1,200 itu/mg) were assessed against mosquitoes aedes aegypti, aedes albopictus, and culex quinquefasciatus using a leco ulv fog generator model 1600 and a scorpion 20 ulv airblast sprayer. laboratory-cultured mosquito adults and larvae were used for ef ... | 1997 | 9474567 |
| the mossie-buster: a hose-driven insecticide delivery tool for the control of container-breeding mosquitoes. | a novel insecticide delivery tool, the mossie-buster, was recently developed to control larval populations from urban breeding sites in townsville, australia. this functional and user-friendly control device directly targets the main breeding sites of aedes aegypti (l.) with a focused delivery of insecticides. the mossie-buster comprises a commercially available device and attachments that mix an insecticide solution into the flow of water emitted from a hose. attached to the device is a trigger ... | 1997 | 9474568 |
| a novel insecticidal serotype of clostridium bifermentans. | a novel clostridium bifermentans strain toxic to mosquito larvae on ingestion was isolated from a soil sample collected from secondary forest floor. this strain was designated as serovar paraiba (c. b. paraiba) according to its specific h antigen. clostridium bifermentans paraiba is most toxic to anopheles maculatus theobald larvae (lc50 = 0.038 mg/liter), whereas toxicity to aedes aegypti (linn.) (lc50 = 0.74 mg/liter) and culex quinquefasciatus say (lc50 = 0.11 mg/liter) larvae was 20 and 3 ti ... | 1997 | 9474569 |
| endogenous protease-activated 66-kda toxin from bacillus thuringiensis subsp. kurstaki active against spodoptera littoralis. | the anti-lepidopteran toxin from sporulated bacillus thuringiensis subsp. kurstaki cells, generated by the proteolytic action of endogenous protease(s) on the protoxin, was purified and studied to identify the effect of such proteolysis on the biochemical nature of the toxin. the active toxin was purified employing anion-exchange chromatography to absolute homogeneity, as indicated by sds-page and western blotting. antisera to the purified toxin (66 kda) crossreacted with the protoxin (132 kda) ... | 1998 | 9485601 |
| bt resistance management. | 1998 | 9487517 | |
| field evaluation of vectobac g, vectobac 12as and bactimos wp against the dengue vector aedes albopictus in tires. | the efficacy of three formulations of bacillus thuringiensis var. israelensis was studied against aedes albopictus in discarded tires. the formulations were: vectobac g (corn cob formulation), vectobac 12as (aqueous suspension), and bactimos wp (wettable powder formulation). both vectobac g and vectobac 12as were effective for 24 hr with more than 80% mortality. both vectobac formulations were significantly more effective than bactimos wp for 24 hr after treatment (p < 0.0005). a week after trea ... | 1997 | 9491362 |
| prevalence of beta-exotoxin, diarrhoeal toxin and specific delta-endotoxin in natural isolates of bacillus thuringiensis. | of newly isolated colonies with the appearance of bacillus thuringiensis, 47.5% were found to produce the parasporal crystals characteristic of this species. these positive isolates were screened using the polymerase chain reaction for their possession of a gene encoding a specific protoxin type, cryib. strains with and without this gene were screened for their ability to produce beta-exotoxin and bacillus cereus-type enterotoxin. it was found that 35% of the isolates possessed the cryib gene; o ... | 1998 | 9495012 |
| molecular and phenotypic characterization of bacillus thuringiensis isolated from leaves and insects | bacillus thuringiensis isolates from the phylloplane of organically cultivated cabbage were characterized using molecular and phenotypic methods. of the 58 isolates under study, 31 belonged to serovar kurstaki, 16 did not react with any of the currently recognized antisera, 7 reacted with known antisera, and 4 could not be serotyped as they were nonmotile. round crystals were found in 26 isolates, while bipyramidal crystals were found in the remaining 32 isolates, all of which had activity to le ... | 1998 | 9500938 |
| isolation and activity of strains of bacillus thuringiensis toxic to larvae of the housefly (diptera: muscidae) and tropical blowflies | several natural isolates of bacillus thuringiensis have been found which are active against larvae of musca domestica, the housefly, as well against larvae of the family calliphoridae. the toxicity is attributed to the cry ib class of protoxin. presolubilization of the toxin was not necessary to induce mortality in any of the insect species assayed. the addition of spores to the delta-endotoxin was, however, essential to inducing significant mortality in larvae of chrysomya albiceps (weid.) and ... | 1998 | 9500943 |
| toxicity and binding properties of the bacillus thuringiensis delta-endotoxin cry1c to cultured insect cells. | a better understanding of the mode of action of bacillus thuringiensis delta-endotoxins is needed to develop strategies which may prevent or slow down selection for resistance. we studied the effect of cry1c on several different cultured insect cell lines by means of toxicity assays, ligand blotting, and toxin binding studies. a clear difference in sensitivity toward cry1c between the insect cell lines was observed. spodoptera frugiperda cell line sf9 was most sensitive, whereas spodoptera exigu ... | 1998 | 9500946 |
| agrobacterium-transformed rice plants expressing synthetic cryia(b) and cryia(c) genes are highly toxic to striped stem borer and yellow stem borer. | over 2,600 transgenic rice plants in nine strains were regenerated from >500 independently selected hygromycin-resistant calli after agrobacterium-mediated transformation. the plants were transformed with fully modified (plant codon optimized) versions of two synthetic cryia(b) and cryia(c) coding sequences from bacillus thuringiensis as well as the hph and gus genes, coding for hygromycin phosphotransferase and beta-glucuronidase, respectively. these sequences were placed under control of the m ... | 1998 | 9501164 |
| insect chitinases: molecular biology and potential use as biopesticides. | chitin, an insoluble structural polysaccharide that occurs in the exoskeletal and gut linings of insects, is a metabolic target of selective pest control agents. one potential biopesticide is the insect molting enzyme, chitinase, which degrades chitin to low molecular weight, soluble and insoluble oligosaccharides. for several years, our laboratories have been characterizing this enzyme and its gene. most recently, we have been developing chitinase for use as a biopesticide to control insect and ... | 1997 | 9501415 |
| sasp (small, acid-soluble spore proteins) and spore properties in bacillus thuringiensis israelensis and bacillus sphaericus. | entomopathogenic bacilli b. thuringiensis israelensis (bti) and b. sphaericus (bf) exhibit low survival on field application. it was previously shown that their spores are very sensitive to different stress effectors (heat, uv light) and especially to osmotic variations. since sasp (small, acid-soluble spore proteins), alpha/beta and gamma type, are involved in spore tolerance to heat, uv light, peroxide, and salt, they were analyzed in bti and bf. the molecular weight, migration pattern and ami ... | 1998 | 9504989 |
| distribution of clostridial cry-like genes among bacillus thuringiensis and clostridium strains. | the presence of two cry-like genes first identified in clostridium bifermentans subsp. malaysia ch18 was investigated in clostridium species including 12 subspecies of clostridium bifermentans, 13 strains of other members of clostridia genus, and 13 different subspecies of bacillus thuringiensis. oligonucleotides designed to amplify the two toxin genes, cmb71 and cmb72, were used. we found that these genes are present in 80% of the clostridium bifermentans strains tested and in 8% of the other c ... | 1998 | 9504991 |
| engineering disease and pest resistance in plants. | improvements in transformation techniques and the isolation of many genes whose transcripts or protein products either have antimicrobial or insecticidal activity or are involved in the synthesis of products with such activities have provided valuable tools for engineering resistance in plants. future exploitation of this technology should provide an environmentally friendly alternative to traditional disease and pest control measures. | 1998 | 9507639 |
| larvicidal toxicity of japanese bacillus thuringiensis against the mosquito anopheles stephensi. | japanese isolates of bacillus thuringiensis were screened for larvicidal activity against the mosquito anopheles stephensi, the urban malaria vector of the indian subcontinent. among more than 30 strains identified, larvicidal activity causing > 80% mortality in 72 h was demonstrated for 41/1449 (2.8%) isolates. the majority of strains and isolates (97.2%) exhibited little or no larvicidal activity. anopheles-active strains belonged to more than 12 h serotypes, especially h3ade (serovar fukuokae ... | 1998 | 9513945 |
| susceptibility of the coffee leaf miner (perileucoptera spp.) to bacillus thuringiensis delta-endotoxins: a model for transgenic perennial crops resistant to endocarpic insects | binding of several bacillus thuringiensis delta-endotoxins was studied on histological midgut sections of larvae of coffee leaf miner perileucoptera coffeella from brazil and perileucoptera sp from madagascar. cryia(a), cryia(b), cryia(c), cryib, cryie, and cryiia were tested for binding, and only cryia(c), cryib, and cryie yielded a positive response. the toxins bound to the whole midgut, and the result was identical on both insect populations. the same toxins, to the number of which cryic was ... | 1998 | 9516547 |
| mechanism of phosphatidylinositol-specific phospholipase c: a unified view of the mechanism of catalysis. | the mechanism of phosphatidylinositol-specific phospholipase c (pi-plc) has been suggested to resemble that of ribonuclease a. the goal of this work is to rigorously evaluate the mechanism of pi-plc from bacillus thuringiensis by examining the functional and structural roles of his-32 and his-82, along with the two nearby residues asp-274 and asp-33 (which form a hydrogen bond with his-32 and his-82, respectively), using site-directed mutagenesis. in all, twelve mutants were constructed, which, ... | 1998 | 9521777 |
| role of dna in the activation of the cry1a insecticidal crystal protein from bacillus thuringiensis. | the cry1a insecticidal crystal protein (protoxin) from six subspecies of bacillus thuringiensis as well as the cry1aa, cry1ab, and cry1ac proteins cloned in escherichia coli was found to contain 20-kilobase pair dna. only the n-terminal toxic moiety of the protoxin was found to interact with the dna. analysis of the crystal gave approximately 3 base pairs of dna per molecule of protoxin, indicating that only a small region of the n-terminal toxic moiety interacts with the dna. it is proposed tha ... | 1998 | 9535923 |
| environmental persistence of bacillus thuringiensis spores following aerial application. | soil and leaf populations of bacillus thuringiensis (bt) were monitored following aerial application of commercial bt formulations at the rate of 72 billion international units per acre per year during a 5-year period. data from soil sample spore counts suggested that bt spores persisted in wasatch forest soils for up to 2 years but they did not proliferate. bt isolates were recovered from leaf samples 12 months post application from sprayed, previously sprayed and from nonsprayed areas. the fre ... | 1998 | 9538032 |
| a rapid and specific method for the identification of bacillus thuringiensis strains by indirect immunofluorescence. | 1998 | 9538037 | |
| spore coat protein synergizes bacillus thuringiensis crystal toxicity for the indianmeal moth | spores from bacillus thuringiensis serovars kurstaki and entomocidus synergized crystal protein toxicity for larvae of the indianmeal moth (plodia interpunctella). preparations of spore-crystal mixtures of either serovar were more toxic for the larvae than either purified spores or crystals alone (based on dry weight). spores lost 53% of their toxicity for the indianmeal moth after 2 h of uv-irradiation, but remained partially toxic (28%) even after 4 h of irradiation. spore coat protein was tox ... | 1998 | 9541564 |
| plasmid patterns of bacillus thuringiensis strains and isolates. | bacillus thuringiensis produces crystal proteins which are toxic to several orders of economically important insects and other invertebrates. the genes encoding these toxins reside mainly on plasmids. this report consists of a comparative analysis of the plasmid content of a number of b. thuringiensis strains and isolates which may facilitate the search for novel toxin genes and other important products of this organism. | 1997 | 9556387 |
| effect of insecticidal crystal proteins of bacillus thuringiensis var. israelensis on the enzymes of rat intestinal brush border membrane vesicles. | in vivo treatment of intestinal brush border membrane vesicles with solubilized insecticidal crystal proteins (icp) from the two strains of b. thuringiensis var. israelensis (vcrc b17 and vcrc mb24) caused no adverse effect on gamma glutamyl transpeptidase, na+k+atpase, sucrase and lactase enzymes. but, exposure of membrane vesicles to solubilized icp's in vitro, lead to significant reduction in the activity of na+k+atpase, sucrase and lactase enzymes. | 1997 | 9567748 |
| cdnas for a chymotrypsinogen-like protein from two strains of plodia interpunctella. | gut proteinases are involved in the solubilization and activation of insecticidal toxins produced by bacillus thuringiensis and may also be involved in resistance development. approximately threefold lower chymotrypsin-like enzyme activity was observed in a bt(entomocidus)-resistant strain of the indianmeal moth, plodia interpunctella, than that in the bt-susceptible strain. because chymotrypsin-like proteinases are involved in bt protoxin activation in p. interpunctella, we compared cdna sequen ... | 1997 | 9569643 |
| phosphatidylcholine activation of bacterial phosphatidylinositol-specific phospholipase c toward pi vesicles. | the effect of different phospholipids on the kinetic behavior of phosphatidylinositol-specific phospholipase c (pi-plc) from bacillus thuringiensis toward pi vesicles has been investigated. cosonicated pc/pi vesicles displayed enhanced hydrolysis of pi when less than 0. 20 mole fraction pc was incorporated into the vesicle; higher mole fractions of pc led to a decrease from the maximum activity mimicking surface dilution of substrate. since the pc could affect pi-plc binding to vesicles, the eff ... | 1998 | 9572869 |
| germination, growth, and sporulation of bacillus thuringiensis subsp. israelensis in excreted food vacuoles of the protozoan tetrahymena pyriformis. | spores of bacillus thuringiensis subsp. israelensis and their toxic crystals are bioencapsulated in the protozoan tetrahymena pyriformis, in which the toxin remains stable. each t. pyriformis cell concentrates the spores and crystals in its food vacuoles, thus delivering them to mosquito larvae, which rapidly die. vacuoles containing undigested material are later excreted from the cells. the fate of spores and toxin inside the food vacuoles was determined at various times after excretion by phas ... | 1998 | 9572947 |
| release of the glycosylphosphatidylinositol-anchored enzyme ecto-5'-nucleotidase by phospholipase c: catalytic activation and modulation by the lipid bilayer. | many hydrolytic enzymes are attached to the extracellular face of the plasma membrane of eukaryotic cells by a glycosylphosphatidylinositol (gpi) anchor. little is currently known about the consequences for enzyme function of anchor cleavage by phosphatidylinositol-specific phospholipase c. we have examined this question for the gpi-anchored protein 5'-nucleotidase (5'-ribonucleotide phosphohydrolase; ec 3.1.3.5), both in the native lymphocyte plasma membrane, and following purification and reco ... | 1998 | 9576857 |
| effects on larvicidal activity of single proline substitutions in alpha3 or alpha4 of the bacillus thuringiensis cry4b toxin. | the possible role of alpha-helices 3 and 4 in toxicity of the dipteran-active bacillus thuringiensis cry4b delta-endotoxin was investigated by employing proline substitutions via site-directed mutagenesis. similar to the wild-type cry4b, the mutant toxins were over-expressed in escherichia coli as cytoplasmic inclusions and were structurally stable upon solubilization and trypsin activation. the substitution of glutamine 149 by proline in the center of helix 4 (q149p) resulted in a nearly comple ... | 1998 | 9584996 |
| investigation of spectral reproducibility in direct analysis of bacteria proteins by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. | matrix-assisted laser desorption/ionization (maldi) time-of-flight mass spectrometry (tofms) can be used for rapid detection of bacteria proteins in a crude mixture. it can potentially be used as a tool for bacterial identification based on the mass spectral patterns or the appearance of some characteristic mass peaks. however, there are many experimental parameters that can potentially have a strong effect on the observed mass spectra. the objective of this work is to address the mass spectral ... | 1998 | 9586233 |
| bacillus thuringiensis insecticidal proteins: molecular mode of action. | growing interest in biorational pesticides has placed the bacillus thuringiensis insecticidal crystal proteins at the forefront of pesticides for plant genetic engineering. the development of improvement pesticides, both in enhanced activity and broader host range, depends on an understanding of its mechanism of action. this review presents a complete overview of the bacterium and the group of insecticidal proteins known as cry proteins or delta-endotoxins. the molecular mode of action is descri ... | 1998 | 9594569 |
| laboratory bioassay to compare susceptibilities of aedes aegypti and anopheles albimanus to bacillus thuringiensis var. israelensis as affected by their feeding rates. | this study presents the effect of differences in the feeding rates of aedes aegypti and anopheles albimanus on their susceptibilities to bacillus thuringiensis israelensis. aedes aegypti was more susceptible than an. albimanus because of its faster rate of feeding. aedes aegypti ingested 11.5 times more spores than did an. albimanus, resulting in lower lt50 values. anopheles albimanus larvae fed at a slower rate and required fewer spores than ae. aegypti to induce 50% mortality. these findings s ... | 1998 | 9599326 |
| cry1ac, a bacillus thuringiensis toxin, triggers extracellular ca2+ influx and ca2+ release from intracellular stores in cf1 cells | intracellular ca2+ concentration was measured in single cf1 cells (choristoneura fumiferana, spruce budworm) loaded with fura-2, a ca2+-sensitive fluorescent probe. cf1 cells displayed ca2+ surges in response to cry1ac and cry1c proteins, two cf1-toxic bacillus thuringiensis products, but not to cry1aa and cry3a, which are not toxic to cf1 cells. in the presence of extracellular ca2+, the toxin-induced ca2+ response was insensitive to methoxyverapamil, a voltage-dependent ca2+ channel blocker, b ... | 1998 | 9600867 |
| cloning and sequencing of three new putative toxin genes from clostridium bifermentans ch18. | three new open reading frames were found downstream from cbm71, a toxin gene from clostridium bifermentans malaysia (cbm) strain ch18. the first one (91bp downstream) called cbm72, is 1857bp long and encodes a 71727-da protein (cbm72) with a sequence similar to that of bacillus thuringiensis delta-endotoxins. this protein shows no significant toxicity to mosquito larvae. the two others, cbm17.1 (462bp) and cbm17.2 (459bp), are copies of the same gene encoding cbm p18 and p16 polypeptides and loc ... | 1998 | 9602158 |
| effects of midgut-protein-preparative and ligand binding procedures on the toxin binding characteristics of bt-r1, a common high-affinity receptor in manduca sexta for cry1a bacillus thuringiensis toxins. | the identity of the physiologically important cry1a receptor protein(s) in the lepidopteran manduca sexta has been a matter of dispute due to the multiple proteins which bind the cry1ac toxin. cry1aa, cry1ab, and cry1ac exhibit essentially identical toxicities toward m. sexta larvae and show a high degree of sequence and presumed structural identities. these similarities make it likely that there is a common mechanism of toxicity in these lepidopteran-specific toxins in terms of both mode of act ... | 1998 | 9603829 |
| expression of a bacillus thuringiensis delta-endotoxin gene by bacillus pumilus. | the delta-endotoxin genes from bacillus thuringiensis were introduced into a rhizosphere-inhabiting bacillus pumilus isolate to create a delta-endotoxin expression and delivery system for subterranean feeding insects such as the larvae of pale western cutworm (agrotis orthogonia morrison (lepidoptera: noctuidae)). preliminary experiments indicated that bacillus thuringiensis subsp. kurstaki cultures were toxic to pale western cutworm larvae. three different cry genes from bacillus thuringiensis ... | 1998 | 9606908 |
| insect resistance of transgenic tobacco expressing an insect chitinase gene. | chitinase expression in the insect gut normally occurs only during moulting, where the chitin of the peritrophic membrane is presumably degraded. thus, insects feeding on plants that constitutively express an insect chitinase gene might be adversely affected, owing to an inappropriately timed exposure to chitinase. this hypothesis was tested by introducing a cdna encoding a tobacco hornworm (manduca sexta) chitinase (ec 3.2.1.14) into tobacco via agrobacterium tumefaciens-mediated transformation ... | 1998 | 9608735 |
| characterization of plasmid paw63, a second self-transmissible plasmid in bacillus thuringiensis subsp. kurstaki hd73. | bacillus thuringiensis subspecies kurstaki hd73, toxic for lepidopteran larvae, contains two large self-transmissible plasmids of approximately 75 kb, pht73 and paw63. the conjugative plasmid pht73 has been studied extensively and has been shown to harbour the toxin gene cry1ac, the transposon tn4430 and several insertion sequences. in this study it was demonstrated that the minor plasmid paw63 is also self-transmissible and about 10-30 times more efficient in mobilizing plasmid pbc16. to facili ... | 1998 | 9611801 |
| [the relationship of the larval behavioral traits of the malarial mosquito anopheles messeae (diptera: culicidae) to its sensitivity to the entomopathogenic bacterium bacillus thuringiensis subspecies israelensis]. | behavioural actions of the malarial mosquito anopheles messeae larvae and their correlations with the susceptibility to the entomopathogenic bacterium bacillus thuringiensis israelensis (bti) were studied. the larvae were differentiated according to their feeding mode ("filter-feeders" and "scraper-feeders") and to their avoidance reaction on a concussion of water surface by water drops ("divers" and "undivers"). the "scraper-feeders" and "divers" showed a tendency of decreased susceptibility to ... | 1998 | 9612818 |
| identification of bombyx mori midgut receptor for bacillus thuringiensis insecticidal cryia(a) toxin. | as part of a study of the mechanism by which bacillus thuringiensis insecticidal crystal protein acts, a bombyx mori receptor to the cryia(a) toxin specific for lepidopterans was examined. histological examination showed that the toxin acted on the brush-border membrane of the midgut columnar cells and broke its infolding structure, causing cell lysis. the membrane vesicles were purified, and a 175-kda protein binding the toxin was found that accounted for some 0.015% of membrane proteins. the p ... | 1998 | 9614702 |
| cloning, sequencing, and expression of the bombyx mori receptor for bacillus thuringiensis insecticidal cryia(a) toxin. | bacillus thuringiensis strains produce insect-specific bt toxins. bt cryia(a) toxin binds to a 175-kda glycoprotein (btr175) on the microvillus membranes of columnar cells in the bombyx mori midgut and causes lysis of the cells. btr175 was purified, and its cdna was cloned. the cdna encodes a newly identified 193.3-kda preproprotein form of btr175 that includes nine extracellular cadherin repeats, a 23.5-kda membrane-proximal domain, a membrane-spanning region, and a 13.6-kda cytoplasmic domain. ... | 1998 | 9614703 |
| an improvement in the dissociating properties of sodium dodecyl sulfate-containing sample buffers used in polyacrylamide gel electrophoresis. | protein complexes present different degrees of stability. we have previously described a glycoprotein from bacillus thuringiensis that appeared as a multimer unable to be dissociated by the usual sds-containing sample buffers of ph 6.8. in order to dissociate the complex, a sds-containing sample buffer of ph 9 was described. in the present report three additional protein complexes with different degrees of stability and the effect of that dissociating sample buffer are described. the study of sd ... | 1998 | 9620454 |
| biological, immunological, and genetic analysis of bacillus thuringiensis isolated from granary in korea. | to isolate a naturally occurring novel bacillus thuringiensis strain, we investigated the distribution, toxicity, morphology, h serotype, and gene type of b. thuringiensis from residue samples of granary in korea. a total of 163 b. thuringiensis isolates out of 411 samples producing spore and crystal were obtained. in toxicity tests, 80% of all isolates were toxic to lepidoptera, and 12% were not toxic to any of tested insects. and dipteran-active and lepidopteran/dipteran-active isolates were r ... | 1998 | 9625790 |
| efficient synthesis of mosquitocidal toxins in asticcacaulis excentricus demonstrates potential of gram-negative bacteria in mosquito control. | the control of mosquitoes with chemical insecticides pollutes the environment and leads to resistance in mosquito populations. bacterial control of mosquito larvae with bacillus sphaericus and bacillus thuringiensis subsp. israelensis, which produce protein toxins, has proved useful, safe, and nonpolluting. these bacteria do, however, suffer from disadvantages, including rapid setting, uv sensitivity, and lack of persistance of spores, proteolysis of toxins, narrow host range, and high productio ... | 1996 | 9630898 |
| another salvo in the plant patent wars. | 1996 | 9630967 | |
| delta-endotoxin proteins associated with spherical parasporal inclusions of the four lepidoptera-specific bacillus thuringiensis strains. | four lepidoptera-specific reference strains of bacillus thuringiensis, belonging to serovars sumiyoshiensis (h3a:3d), fukuokaensis (h3a:3d:3e), darmstadiensis (h10a:10b) and japonensis (h23), which produce spherical parasporal inclusions, were examined for comparative characterization of delta-endotoxins. sds-page profiles of the alkali-solubilized parasporal inclusions revealed the presence of single major protein bands of 130 kda in the four strains. chymotrypsin and trypsin treatment of the p ... | 1998 | 9633648 |
| overproduction of encapsulated insecticidal crystal proteins in a bacillus thuringiensis spo0a mutant. | the spo0a gene of bacillus subtilis encodes the key factor involved in the initiation of sporulation. it was previously shown that the b. thuringiensis (bt) cryiiia gene, encoding a toxin active against coleopteran larvae, is overexpressed in an spo0a mutant of b. subtilis. in this paper we describe the construction of a bt spo0a mutant strain and its use to produce insecticidal crystal proteins. the spo0a gene of bt was cloned and identified by its ability to transform a b. subtilis spo0a mutan ... | 1995 | 9634751 |
| amplification of a chimeric bacillus gene in chloroplasts leads to an extraordinary level of an insecticidal protein in tobacco. | the bacillus thuringiensis (bt) crystal toxins are safe biological insecticides, but have short persistance and are poorly effective against pests that feed inside plant tissues. production of effective levels of these proteins in plants has required resynthesis of the genes encoding them. we report that amplification of an unmodified cryla(c) coding sequence in chloroplasts up to approximately 10,000 copies per cell resulted in the accumulation of an unprecedented 3-5% of the soluble protein in ... | 1995 | 9634777 |
| transgenic indica rice breeding line ir58 expressing a synthetic cryia(b) gene from bacillus thuringiensis provides effective insect pest control. | the indica rice breeding line ir58 was transformed by particle bombardment with a truncated version of a synthetic cryia(b) gene from bacillus thuringiensis. this gene is expressed under control of the camv 35s promoter and allows efficient production of the lepidopteran specific delta-endotoxin. r0, r1 and r2 generation plants displayed a significant insecticidal effect on several lepidopterous insect pests. feeding studies showed mortality rates of up to 100% for two of the most destructive in ... | 1996 | 9636319 |
| cloning and expression of full-length delta-endotoxin cryia(c) gene in three kinds of prokaryotic systems using shuttle vector pht3101. | two fragments, 6.5kb and 4.3kb encoding 5' end and 3' end of delta-endotoxin cryia(c) gene, respectively, were selected from the bacillus thuringiensis kurstaki-hd-73 75kb plasmid gene pool using random primer labelling delta-endotoxin cryia(b) gene probe. the full-length 3.92kb cryia(c) gene including 5' end 152 bp promoter sequence and 3' end 198 bp terminater sequence was rebuilt after uncoding sequences were deleted. three kinds of engineering strains harbouring the same recombinant plasmid ... | 1996 | 9639817 |
| [distribution of bacillus thuringiensis in soils of north and south of china]. | 221 isolates of bacillus thuringiensis were isolated in 1491 soil samples from north and south of china. h-serotypes and larvicidal characters of all bt isolates have been identified. the rate of bt-harbouring soil sample and the rate of bt isolates in northeast and neimeng were in 12.6% and 17.2% respectively. predominant serotypes were h4, h10, h3, h13, h5 and h29. the most fertile bt-harbouring area was the heilongjiang province with rate of bt-harbouring sample of 21.4% and rate of bt isolat ... | 1996 | 9639831 |
| [characterization of insecticidal crystal proteins of bacillus thuringiensis subsp. chinensis ct-43]. | bacillus thuringiensis subsp. chinensis ct-43, no flagellum, produces various shaped parasporal crystals, which consist of 140000, 130000, and 65000 proteins. based on two kinds of mutant, 140000 and 130000 crystal protein individually forms bipyramidal crystal and the 65000 protein forms cubidal crystal, and that the 140000 and 130000 protein is activated by trypsin into 55000 and 66000 proteins and 60000 protein, respectively. bioassay were conducted to 3rd instar plutella xylostella larvae wi ... | 1996 | 9639832 |
| insecticidal toxins from the bacterium photorhabdus luminescens. | transgenic plants expressing bacillus thuringiensis (bt) toxins are currently being deployed for insect control. in response to concerns about bt resistance, we investigated a toxin secreted by a different bacterium photorhabdus luminescens, which lives in the gut of entomophagous nematodes. in insects infected by the nematode, the bacteria are released into the insect hemocoel; the insect dies and the nematodes and bacteria replicate in the cadaver. the toxin consists of a series of four native ... | 1998 | 9641921 |
| histopathological effects of bacillus thuringiensis on the alimentary canal of the sheep louse, bovicola ovis. | sequential observations were made of the ultrastructural effects of bacillus thuringiensis (bt) subsp. kurstaki strain wb3s16 on midgut epithelial cells of the sheep biting louse, bovicola ovis, after the lice were fed, ad libitum, a powdered preparation of bt spores, delta-endotoxin crystals, and lysed cellular components. light microscope observations revealed cytopathological changes to the midgut epithelial cells 4 h postfeeding. transmission electron micrographs showed that the microvilli o ... | 1998 | 9647696 |
| processing of delta-endotoxin of bacillus thuringiensis subsp. kurstaki hd-1 in heliothis armigera midgut juice and the effects of protease inhibitors. | bombyx mori was found to be more sensitive to the protoxins of hd-1 than heliothis armigera. sds-page analysis showed that a large amount of activated toxin was yielded from protoxin by b. mori gut juice while little was yielded by h. armigera. further degradation of activated toxin was observed in h. armigera midgut juice detected by sds-page. ph influenced the proteolytic activity of the midgut juice significantly, but there was no obvious effect of ph on the degradation of activated toxin. sp ... | 1998 | 9647704 |
| bacillus thuringiensis subsp. konkukian (serotype h34) superinfection: case report and experimental evidence of pathogenicity in immunosuppressed mice. | we present a case of severe war wounds infected by bacillus thuringiensis serotype h34 and describe the experimental protocol used to demonstrate its ability to infect mice after cutaneous inoculation. this case is interesting because b. thuringiensis is considered to be a contaminant in laboratories and receives inadequate attention. | 1998 | 9650985 |
| kinetics of conjugative transfer: a study of the plasmid pxo16 from bacillus thuringiensis subsp. israelensis. | the aggregation-mediated conjugation system of bacillus thuringiensis subsp. israelensis, encoded by the 200-kb plasmid pxo16, is highly potent in transferring itself and efficient in mobilizing other nonconjugative plasmids. the present study reveals some salient features of this conjugation system. our observations can be summarized as follows: (i) the conjugative transfer takes about 3(1/2) to 4 min. for a 200-kb plasmid this corresponds to about 1 kb per second. (ii) the ability to transfer ... | 1998 | 9657931 |
| chloroplast-transgenic plants: panacea--no! gene containment--yes! | 1998 | 9661173 | |
| genetic diversity of bacillus cereus/b. thuringiensis isolates from natural sources. | the genetic diversity and relationships among 154 bacillus cereus/b. thuringiensis isolates recovered from soil samples from five geographic areas in norway were investigated with multilocus enzyme electrophoresis (mee). cluster analysis revealed two major groups (designated cluster i and cluster ii) separated at genetic distance greater than 0.55. cluster i included 62 electrophoretic types (ets) originating from all five locations, whereas, in cluster ii, all but one isolate were from the same ... | 1998 | 9662607 |
| the bacillus spoiiga protein is targeted to sites of spore septum formation in a spoiie-independent manner. | the process of bacterial cell division involves the assembly of a complex of proteins at the site of septation that probably provides both the structural and the cytokinetic functions required for elaboration and closure of the septal annulus. during sporulation in bacillus subtilis, this complex of proteins is modified by the inclusion of a sporulation-specific protein, spoiie, which plays a direct role in gene regulation and also has a genetically separable role in determining the gross struct ... | 1998 | 9663680 |
| laboratory and field evaluation of efficacy of vectobac 12as against culex sitiens (diptera: culicidae) larvae. | laboratory bioassay studies of the efficacy of vectobac 12as (active ingredient: 1,200 international toxic units [itu]/mg bacillus thuringiensis var. israelensis) against field-collected late 3rd/early 4th-instar larvae of culex sitiens indicated excellent control potential. a 95% lethal concentration (lc95) value of 1.381 x 10(7) itu was calculated, which equated to a dosage of 0.011 liters/ha. this dosage represented 1.8% of the recommended lowest dosage rate for the product. a field trial of ... | 1998 | 9673920 |
| characterization of mosquito larvicidal parasporal inclusions of a bacillus thuringiensis serovar higo strain. | the parasporal inclusion proteins of the type strain of bacillus thuringiensis serovar higo (h44), that have moderate mosquitocidal activity, were characterized. the purified parasporal inclusions, spherical in shape, were examined for activity against the two mosquito species, culex pipiens molestus and anopheles stephensi and the moth-fly, telmatoscopus albipunctatus. the lc50 values of the inclusion for the two mosquitoes were 3.41 and 0.15 microgram.ml-1, respectively. no mortality was shown ... | 1998 | 9674143 |
| isolation of a strain of bacillus thuringiensis ssp. kurstaki hd-1 encoding delta-endotoxin cry1e. | a strain of bacillus thuringiensis, stb-1, toxic against spodoptera exigua, was isolated. bacillus thuringiensis stb-1 produced bipyramidal inclusions and reacted with the h antiserum of b. thuringiensis ssp. kurstaki. the plasmid and protein profiles of b. thuringiensis stb-1 were compared with those of its reference strains, ssp. kurstaki and ssp. kenyae. to verify the gene type of b. thuringiensis stb-1, pcr analysis was performed with spodoptera-specific cry gene primers. the result showed t ... | 1998 | 9674170 |
| discrimination among bacillus cereus, b. mycoides and b. thuringiensis and some other species of the genus bacillus by fourier transform infrared spectroscopy. | fourier transform infrared spectroscopy (ftir) in conjunction with canonical variate analysis was found to be effective in discriminating among spectra of 9 representative strains of bacillus spp., including b. cereus, b. mycoides and b. thuringiensis. the method was also able to discriminate according to species among spectra of 14 other non-type strains of b. cereus, 12 of b. mycoides and 12 of b. thuringiensis with a success rate of > 95%, even without using a prior classification of the grou ... | 1998 | 9675865 |
| bacillus thuringiensis cry1ac toxin interaction with manduca sexta aminopeptidase n in a model membrane environment. | the bacillus thuringiensis cry1ac delta-endotoxin was shown to bind in a biphasic manner to manduca sexta aminopeptidase n (apn) present in a novel model membrane. surface plasmon resonance analysis allowed the quantification of toxin binding to m. sexta apn in a supported lipid monolayer. the initial binding was rapid and reversible, with an affinity constant of 110 nm. the second phase was slower and resulted in an overall affinity constant of 3.0 nm. reagents used to disrupt protein-protein i ... | 1998 | 9677328 |
| identification of bacillus cereus by fourier transform infrared spectroscopy (ftir). | the objective of this study was to evaluate the potential of fourier transform infrared spectroscopy (ftir) for rapid identification of bacillus cereus isolates. ten b. cereus group isolates (comprising b. cereus, bacillus mycoides, and bacillus thuringiensis strains), five other bacillus spp., and five non-bacillus spp. were used. two types of media, brain heart infusion (bhi) and trypticase soy agar (tsa), were tested. the results indicated that all b. cereus group isolates produced characteri ... | 1998 | 9678183 |
| quantitative analysis of thuringiensin by high-performance liquid chromatography using adenosine monophosphate as an internal standard. | an analytical method for thuringiensin using adenosine monophosphate (amp) as an internal standard is established. amp, with high stability and availability, is an appropriate internal standard for thuringiensin quantitative analysis using high-performance liquid chromatography and ultraviolet absorbance detection at 260 nm. a good correlation between the concentration of thuringiensin and the peak-area ratios of thuringiensin to amp is demonstrated. from this general equation of linear regressi ... | 1998 | 9679301 |
| phage display of a biologically active bacillus thuringiensis toxin. | activated forms of bacillus thuringiensis insecticidal toxins have consistently been found to form insoluble and inactive precipitates when they are expressed in escherichia coli. genetic engineering of these proteins to improve their effectiveness as biological pesticides would be greatly facilitated by the ability to express them in e. coli, since the molecular biology tools available for bacillus are limited. to this end, we show that activated b. thuringiensis toxin (cry1ac) can be expressed ... | 1998 | 9687463 |
| microcosm enrichment of biphenyl-degrading microbial communities from soils and sediments. | a microcosm enrichment approach was employed to isolate bacteria which are representative of long-term biphenyl-adapted microbial communities. growth of microorganisms was stimulated by incubating soil and sediment samples from polluted and nonpolluted sites with biphenyl crystals. after 6 months, stable population densities between 8 x 10(9) and 2 x 10(11) cfu/ml were established in the microcosms, and a large percentage of the organisms were able to grow on biphenyl-containing minimal medium p ... | 1998 | 9687466 |
| a novel insecticidal toxin from photorhabdus luminescens, toxin complex a (tca), and its histopathological effects on the midgut of manduca sexta | photorhabdus luminescens is a bacterium which is mutualistic with entomophagous nematodes and which secretes high-molecular-weight toxin complexes following its release into the insect hemocoel upon nematode invasion. thus, unlike other protein toxins from bacillus thuringiensis (delta-endotoxins and vip's), p. luminescens toxin (pht) normally acts from within the insect hemocoel. unexpectedly, therefore, the toxin complex has both oral and injectable activities against a wide range of insects. ... | 1998 | 9687470 |
| distribution, serological identification, and pcr analysis of bacillus thuringiensis isolated from soils of korea. | a total, 58 strains of bacillus thuringiensis were isolated from soils of various regions in korea. serological tests showed that b. thuringiensis isolates represented 10 h serotypes, indicating a varied flora of b. thuringiensis. but the h serotypes did not have a significantly uneven distribution, ranging from 1 to 11 isolates. in toxicity tests, 35% of all isolates were toxic to lepidoptera, 20% were toxic to diptera, and 9% were non-toxic isolates. especially, a large number of lepidopteran/ ... | 1998 | 9688820 |
| construction of occluded recombinant baculoviruses containing the full-length cry1ab and cry1ac genes from bacillus thuringiensis. | the administration of baculoviruses to insects for bioassay purposes is carried out, in most cases, by contamination of food surfaces with a known amount of occlusion bodies (obs). sinceper os infection is the natural route of infection, occluded recombinant viruses containing crystal protein genes (cry1ab and cry1ac) from bacillus thuringiensis were constructed for comparison with the baculovirus prototype autographa californica nucleopolyhedrovirus (acnpv). the transfer vector pacuw2b was used ... | 1998 | 9698820 |
| larvicidal efficacy of bacillus sphaericus h-5a, 5b and b. thuringiensis var. israelensis h-14 against malaria vectors in bhabar area, district naini tal, u.p. | 1997 | 9699425 | |
| premature polyadenylation at multiple sites within a bacillus thuringiensis toxin gene-coding region. | some foreign genes introduced into plants are poorly expressed, even when transcription is controlled by a strong promoter. perhaps the best examples of this problem are the cry genes of bacillus thuringiensis (b.t.), which encode the insecticidal proteins commonly referred to as b.t. toxins. as a step toward overcoming such problems most effectively, we sought to elucidate the mechanisms limiting the expression of a typical b.t.-toxin gene, cryia(c), which accumulates very little mrna in tobacc ... | 1998 | 9701599 |
| direct evidence for rapid degradation of bacillus thuringiensis toxin mrna as a cause of poor expression in plants. | it is well established that the expression of bacillus thuringiensis (b.t.) toxin genes in higher plants is severely limited at the mrna level, but the cause remains controversial. elucidating whether mrna accumulation is limited transcriptionally or posttranscriptionally could contribute to effective gene design as well as provide insights about endogenous plant gene-expression mechanisms. to resolve this controversy, we compared the expression of an a/u-rich wild-type cryia(c) gene and a g/c-r ... | 1998 | 9701600 |
| [features of the production of cryiiia delta-endotoxin from bacillus thuringiensis in a recombinant strain of pseudomonas putida under control of pm and xyls regulatory elements]. | the addition of 3-methyl benzoate to the culture of the recombinant strain pseudomonas putida ipm-36 (bearing the cryiiia gene of b. thuringiensis subsp, tenebrionis under the control of the pm promoter and the regulator gene xyls) slowed down the growth rate of the recombinant strain and increased, under non-selective conditions, the number of plasmid-free cells. intense synthesis of the coleoptera-specific delta-endotoxin encoded by the cryiiia gene began 6-8 h after the addition of the induce ... | 1998 | 9702728 |
| [the effect of infection by the entomopathogenic bacterium bacillus thuringiensis on the spread of microsporidia in an inversion-polymorphic population of the malarial mosquito anopheles messeae (diptera: culicidae)]. | a specificity of distribution of the microsporidia parathelohania sp. in a natural population of anopheles messeae and in those, which survived after the treatment by subspecies bacillus thuringiensis fukuokaensis, b. t. darmstadiensis and b. t. kyushuensis (pathotype b), were observed. the microsporidia parathelohania sp. affected males and it did not show a genotypic specificity in control, but it had a genotypic specificity after the b. thuringiensis subspecies treatment. | 1998 | 9702802 |
| a novel class of mosquitocidal delta-endotoxin, cry19b, encoded by a bacillus thuringiensis serovar higo gene. | partially digested hincii fragments of dna from a mosquitocidal strain of bacillus thuringiensis serovar higo were cloned into pbluescript ii sk(+) and propagated in escherichia coli. recombinant cells were screened immunologically for the production of parasporal inclusion antigens. one e. coli clone harboring a recombinant plasmid exhibited larvicidal activity to culex pipiens molestus, but not to anopheles stephensi. hybridization experiments revealed that the gene of the toxin protein is loc ... | 1998 | 9704107 |
| effect of a formulation of bacillus thuringiensis berliner var. kurstaki on podisus nigrispinus dallas (heteroptera: pentatomidae: asopinae). | 1998 | 9709021 | |
| differential effects of helper proteins encoded by the cry2a and cry11a operons on the formation of cry2a inclusions in bacillus thuringiensis. | to compare the differential effects of cry2a operon orf2 (29-kda protein gene) and cry11a operon orf3 (20-kda protein gene) on cry2a synthesis and inclusion formation, we expressed the cry2a gene along with either the 29-kda gene, 20-kda gene, or both genes. constructs containing 20-kda, in the presence or absence of 29-kda, produced more cry2a than constructs which lacked this gene. cry2a synthesis was also higher when the 29-kda gene was included with 20-kda in the construct. however, even in ... | 1998 | 9711837 |
| analysis of 66 kda toxin from bacillus thuringiensis subsp. kurstaki reveals differential amino terminal processing of protoxin by endogenous protease(s). | the endogenous protease(s) activated crystal toxin from bacillus thuringiensis subsp. kurstaki was purified and examined. the purified toxin was homogenous, as demonstrated by two-dimensional polyacrylamide gel electrophoresis and contained 1.38 mumoles neutral sugar and 9 nmoles sialic acid per mg protein amino terminal amino acid sequence data revealed that the toxin is a cleavage product of 132 kda protoxin with glutamic acid-30 of the deduced amino acid sequence of the crystal protein (schne ... | 1998 | 9713700 |
| limited proteolysis of bacillus thuringiensis cryig and cryivb delta-endotoxins leads to formation of active fragments that do not coincide with the structural domains. | bacillus thuringiensis "true" toxins consist of three domains: the n-terminal, alpha-helical domain followed by two beta-structural domains. their limited proteolysis does not proceed at the domain boundaries, but is directed to the loops within the domains. there are at least two patterns of the limited proteolysis of "true" toxins. the first pattern, observed for cryia and cryivd delta-endotoxins, results in the proteolysis of the loops connecting beta-strands of the second domain. the second ... | 1998 | 9717741 |
| involvement of chitinases of bacillus thuringiensis during pathogenesis in insects. | bacillus thuringiensis subsp. israelensis ips78 and b. thuringiensis subsp. aizawai hd133 both secreted exochitinase activity when grown in a medium containing chitin. allosamidin, a specific chitinase inhibitor, inhibited activity from both strains, with ic50 values of about 50 microm with colloidal chitin as substrate and between 1 and 10 microm with 4-methylumbelliferyl-diacetylchitobioside and 4-methylumbelliferyl-triacetylchitotrioside as substrates. the involvement of these chitinolytic ac ... | 1998 | 9720040 |
| natural born killers. | this year, 30 million acres of the corn, cotton, and potatoes planted in the united states will have been genetically engineered to produce an endotoxin normally found in the microbe bacillus thuringiensis (bt), a self-contained pesticide that will be toxic only to target insects. transgenic pest-resistant crops are a cost-effective alternative to chemical pesticides, and may offer a way to help feed the world's growing population with minimal environmental impact. | 1998 | 9721262 |
| isolation of aerobic microbes from ixodes scapularis (acari: ixodidae), the vector of lyme disease in the eastern united states. | the spirochete borrelia burgdorferi johnson, schmid, hyde, steigerwalt & benner is transmitted by ixodes scapularis say, a vector of lyme disease. as a 1st step into investigating the possibility of biocontrol of the tick, we identified the microbiota associated with the ticks. we collected, identified, and determined the sex of ticks from foliage and deer. seventy-three initial bacterial isolates were recovered from 43 ticks (27 adults and 16 nymphs). the bacteria isolated from nymphs were qual ... | 1998 | 9725033 |
| discrimination of psychrotrophic and mesophilic strains of the bacillus cereus group by pcr targeting of major cold shock protein genes. | detection of psychrotrophic strains (those able to grow at or below 7 degreesc) of the bacillus cereus group (bacillus cereus, bacillus thuringiensis, and bacillus mycoides) in food products is at present extremely slow with conventional microbiology. this is due to an inability to discriminate these cold-adapted strains from their mesophilic counterparts (those able to grow only above 7 degreesc) by means other than growth at low temperature, which takes 5 to 10 days for detection. here we repo ... | 1998 | 9726910 |
| molecular cloning of a gpi-anchored aminopeptidase n from bombyx mori midgut: a putative receptor for bacillus thuringiensis cryia toxin. | an aminopeptidase n (apn) with a molecular weight of 110kda was released from the midgut membrane of bombyx mori by phosphatidylinositol-specific phospholipase c (pi-plc), and purified to a homogeneous state. this 110-kda apn was different from the 100-kda apn that we previously reported, in chromatographic behaviors, substrate specificity, and n-terminal and internal amino acid sequences. however, the n-terminal sequence of 110-kda apn, dpafrlptttrprhyqvtlt, was highly homologous with those of ... | 1998 | 9729121 |
| bacillus thuringiensis and its pesticidal crystal proteins. | during the past decade the pesticidal bacterium bacillus thuringiensis has been the subject of intensive research. these efforts have yielded considerable data about the complex relationships between the structure, mechanism of action, and genetics of the organism's pesticidal crystal proteins, and a coherent picture of these relationships is beginning to emerge. other studies have focused on the ecological role of the b. thuringiensis crystal proteins, their performance in agricultural and othe ... | 1998 | 9729609 |
| revision of the nomenclature for the bacillus thuringiensis pesticidal crystal proteins. | the crystal proteins of bacillus thuringiensis have been extensively studied because of their pesticidal properties and their high natural levels of production. the increasingly rapid characterization of new crystal protein genes, triggered by an effort to discover proteins with new pesticidal properties, has resulted in a variety of sequences and activities that no longer fit the original nomenclature system proposed in 1989. bacillus thuringiensis pesticidal crystal protein (cry and cyt) nomen ... | 1998 | 9729610 |
| localization of putative virulence genes on a physical map of the bacillus thuringiensis subsp. gelechiae chromosome | the insect pathogen bacillus thuringiensis (bt) has earlier been shown to possess virulence factors in addition to the crystal toxins. bt subsp. gelechiae strain bt13 lacks crystals but is still virulent to lepidopteran insects. among the virulence co-expressed genes are two phospholipases; phosphatidylinositol-specific phospholipase c (pi-plc) and phosphatidylcholine-degrading phospholipase c (pc-plc), flagellin, and beta-lactamase i. in addition to these putative virulence factors the toxic ne ... | 1998 | 9732531 |
| surface plasmon resonance analysis at a supported lipid monolayer. | methods for the formation of supported lipid monolayers on top of a hydrophobic self assembled monolayer in a surface plasmon resonance instrument are described. small unilamellar vesicles absorb spontaneously to the surface of the hydrophobic self-assembled monolayer to form a surface which resembles the surface of a cellular membrane. lipophilic ligands, such as small acylated peptides or glycosylphosphatidylinositol-anchored proteins, were inserted into the absorbed lipid and binding of analy ... | 1998 | 9733935 |
| biochemical characterization of the third domain from bacillus thuringiensis cry1a toxins. | cry proteins from bacillus thuringiensis have insecticidal properties. the function of domains i and ii has been described but domain iii has so far eluded understanding. domain iii from cry1ab and cry1ac has been cloned, expressed in e. coli and injected to rabbits with the aid of characterizing them immunologically. interestingly, polyclonal antibodies against cry1ab fragment did not recognize either the native cry1ab toxin or the cry1ac fragment while those against the latter did recognize ei ... | 1998 | 9739466 |