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a. m. heimpel (1923-1979): an appreciation. 19807003024
deposit assessment of bacillus thuringiensis formulations applied from an aircraft.deposit assessment after aerial spraying with bacillus thuringiensis (b.t.) formulations consists of the analysis of the splash of droplets on kromekote papers and determining the number of bacterial colonies growing on nutrient agar medium petri dishes. however, neither of these two methods provides a number of spores deposited although this figure is essential to determine treatment efficiency. both methods are evaluated with regard to this need and a new approach is suggested.19807011511
cloning and expression of the bacillus thuringiensis crystal protein gene in escherichia coli.sau 3a1 partial digestion fragments from bacillus thuringiensis var. kurstaki hd-1 plasmid dna were ligated into the bamhi site of the cloning vector pbr322 and transformed into escherichia coli strain hb101. colonies presumed to contain recombinant plasmids were screened for production of an antigen that would react with antibody made against b. thuringiensis crystals. one strain, es12, was isolated by using this procedure. es12 contains a plasmid of mr 11 x 10(6) that has dna sequence homology ...19817019914
the entomocidal toxins of bacillus thuringiensis. 19817025037
a new subfamily of microbial serine proteinase? structural similarities of bacillus thuringiensis and thermoactinomyces vulgaris extracellular serine proteinases. 19817028036
[extracellular serine proteinase of bacillus thuringiensis].pure extracellular serine proteinase has been isolated from a broth filtrate of bacillus thuringiensis, strain 69-6r by fractionation with ammonium sulfate and affinity chromatography on sepharose 4b derivatives containing p-(omega-aminomethyl)-phenylboronic acid and cyclopeptide bacillichin as ligands. the enzyme is completely inactivated by phenylmethylsolfonyl fluoride, a specific reagent for serine proteinases, has the molecular weight of 29 000 and pi of 8.4, reveals maximal activity and st ...19817028140
[cloning and the expression of the dna promotor fragments of bacillus thuringiensis in escherichia coli cells].the promoter-containing fragments of bacillus thuringiensis subsp. galleria 69-6 dna have been cloned on the pga24 vector in escherichia coli cells. the recombinant plasmids make cells resistant to tetracycline in a wide range. the level of tetracycline-resistance does not depend on the length of a foreign insertion. new polypeptides are synthesized on the template of the recombinant plasmids in vitro. the data point out the presence in bac. thuringiensis dna of many genes which are able to expr ...19817033045
[distribution, homology and cloning of cryptic bacillus thuringiensis plasmids].the 69-6 strain of bacillus thuringiensis subsp. galleriae harbours at least 7 cryptic plasmids (pbtg1 - pbtg7) with molecular lengths 8,4 to 15,7 kb. according to hybridization analysis, the plasmid pbtg2 (8,7 kb) and other plasmids of the same host strain as well as cryptic plasmids of the strains belonging to 10 other serotypes of bac. thuringiensis share detectable homology. as shown by the data of heteroduplex analysis, about 60% of pbtg1 and pbtg2 genomes have homologous dna sequences. the ...19827037539
[effect of different carbon and purine nucleotide sources on exoprotease synthesis by bacillus thuringiensis].bacillus thuringiensis cells, depending on their physiological state, produce different quantities of exoprotease. easily metabolizable carbon sources in the medium can affect the process in the opposite way: they inhibit synthesis of the enzyme by the cells in the exponential growth phase, and stimulate it by the sporulating cells. apparently, camp is not an effector of catabolite repression regulating exoprotease synthesis by the cells in the exponential growth phase, inspite of stimulating th ...19827040922
ultrastructural analysis of membrane development during bacillus thuringiensis sporulation. 19827077740
enzyme-linked immunosorbent assays for detection and quantitation of the entomocidal parasporal crystalline protein of bacillus thuringiensis subspp. kurstaki and israelensis.an enzyme-linked immunosorbent assay was used to detect and quantitate the parasporal crystal toxins of bacillus thuringiensis subspp. kurstaki and israelensis. the assay method described is extremely sensitive, accurate, and highly specific. with this technique, crystalline insecticidal proteins from several subspecies of b. thuringiensis were compared. the dipteran crystal toxin produced by b. thuringiensis subsp. israelensis was shown to share few epitopes with the lepidopteran toxin from b. ...19827081987
relationship of the syntheses of spore coat protein and parasporal crystal protein in bacillus thuringiensis.two major classes of polypeptides were extracted from the spore surface of bacillus thuringiensis subsp. kurstaki: the 134,000-dalton protoxin that is the major component of the crystalline inclusion and spore coat polypeptides very similar to those found on bacillus cereus spores. the quantity of spore coat polypeptides produced was reduced when compared with that produced by certain acrystalliferous mutants or by b. thuringiensis subsp. israelensis. the latter organism produced an inclusion to ...19827085565
[electron microscope study of "bacillus thuringiensis" var. "israelensis" sporulation and crystal biogenesis (author's transl)].the sporulation and crystal development of bacillus thuringiensis serotype h-14 was described for a wild spore- and crystal-forming strain and for a mutant crystal but non spore-forming strain. the special nature of the israelensis var. consisted in the composite structure of the crystal, made of a number of components differing in size, shape and electron density. the components were formed in a single inclusion or sometimes separately inside the same bacterial cell.19827103310
[participation of bacillus thuringiensis plasmids in the synthesis of an insecticidal delta-endotoxin]. 19827105967
large river treatment with bacillus thuringiensis (h-14) for the control of simulium damnosum s.l. in the onchocerciasis control programme.complete mortality of simulium damnosum theobald s.l. larvae was obtained along a 19 km stretch of the marahoué river including and downstream of the danangoro rapids complex in the bandama basin of ivory coast after treatment with 1.5 ppm/10 min of the sandoz 402-1-wdc formulation of bacillus thuringiensis berliner serotype h-14. partial control was observed for an additional 15 km. the level of control was especially encouraging considering the low concentration (.8%) of active ingredient in t ...19827112688
[antibiotic sensitivity of bacillus thuringiensis var. galleriae strains].bacillus thuringiensis strains forming colonies of the s and r morphology were found to be susceptible to streptomycin, chloramphenicol, rifampicin, neomycin, lincomycin, monomycin, kanamycin, and resistant to ampicillin and polymyxin. the s strains were shown to be susceptible to tetracycline (tets), whereas the r strains were either susceptible (tets) or resistant (tetr). the population of tetr strains was heterogeneous in its resistance to tetracycline (the frequency of tetr cells was from 10 ...19827121329
[differences in primary structures of delta-endotoxins produced by various serotypes of bacillus thuringiensis].the primary structures of delta-endotoxins (crystal-forming proteins) produced by two serotypes of bacillus thuringiensis--v (var. galleriae) and iii (var. alesti) were compared. these proteins differ by the specificity of their action on lepidoptera larvae as well as by their molecular weights. to evaluate the homology of primary structures the tryptic hydrolysates of both endotoxins were fractionated by ion-exchange and thin-layer cellulose chromatography with a subsequent amino acid determina ...19827138972
effect of strain and medium variation on mosquito toxin production by bacillus thuringiensis var. israelensis.the effect of strain variation and culture medium on production of toxin lethal to mosquito larvae by bacillus thuringiensis var. israelensis serotype h-14 was investigated. shake flask culture of b. thuringiensis h-14 strains showed varied ability to produce toxins lethal to mosquito larvae dependent upon the particular strain and growth medium used. buffered media demonstrated no better mosquito toxicity than did unbuffered media that ranged in ph from 5.7 to 8.1 at harvest. although toxin pro ...19827139413
[effect of physicochemical factors on bacillus thuringiensis sporulation].spore germination was studied in bacillus thuringiensis subsp. galleriae. optimal temperature regimes were selected for spore activation and initiation. the formation of spores and the rate of their subsequent germination were shown to depend on the composition of growth media in which the organism was cultivated. the paper describes changes in the fine structure of spores at different stages of their germination.19827144612
laboratory evaluation of bacillus thuringiensis var. israelensis serotype h-14 against mosquito larvae with particular reference to aedes aegypti. 19827153478
activity of a "thermostable exotoxin" of bacillus thuringiensis subsp. morrisoni in the salmonella/microsomal assay for bacterial mutagenicity. 19827153535
[study of sporulation of the bacterium bac. thuringiensis apropos of its infection by phages, using the method of mathematical planning of experiments]. 19827168255
[initiators and inhibitors of spore germination of bacillus thuringiensis]. 19827176973
[bacillus thuringiensis bacteriophage interference].strains of bacillus thuringiensis lysogenic for temperate bacteriophage tm2 inhibit the development of virulent bacteriophage tg4, although the latter can absorb to and kill these bacteria. tm2 mediated interference did not act directly on the tg4 genome; rather, the phage altered the host physiology. the latent period of tg4 growth in bac. thuringiensis lysogenic for phage tm2 was longer than when nonlysogenic bacteria were infected. progeny yields have been counted in bac. thuringiensis strain ...19817198072
[hygienic basis of processes utilizing plant products grown using bac. thuringiensis-based bacterial insecticides]. 19807203061
purification and characterization of the entomocidal protoxin of bacillus thuringiensis.a procedure for purifying the insecticidal parasporal protoxin of bacillus thuringiensis and a description of its biochemical and biophysical properties is provided. mild alkali titration was necessary to generate a functional protoxin in a soluble form, and anion-exchange chromatography was used to remove contaminating cytoplasmic proteases that are nonspecifically bound to whole native parasporal crystals. polyacrylamide gel electrophoresis, gel filtration chromatography, and meniscus depletio ...19817204384
[lysogeny in bacillus thuringiensis].different strains of several bacillus thuringiensis serotypes were analyzed for lysogeny. all of the studied cultures released phages. phages with an isometric capsid and a noncontractible tail were detected in preparations of the majority of the cultures. the growth of a group of related phages was limited upon lysogenization of the galleriae serotype with tm2 phage isolated from a culture of the morrisoni serotype. the physico chemical parameters of the phages were determined.19807207263
[growth characteristics of polylysogenic culture of bacillus thuringiensis subspecies galleriae in a chemostat]. 19807207265
transformation of bacillus thuringiensis subsp. galleria protoplasts by plasmid pbc16.protoplasts of the entomopathogenic bacterium bacillus thuringiensis subsp. galleria were transformed by plasmid pbc16. the frequency of transformation was much lower than that of bacillus subtilis. all isolated b. thuringiensis transformants were characterized by increased sensitivity to lysozyme as compared with the original strain.19817217007
occurrence of resistance to neomycin and kanamycin in bacillus popilliae and certain serotypes of bacillus thuringiensis: mutation potential in sensitive strains. 19817240780
[specificity and active principle of bacillus thuringiensis var. israelensis].bio-assays of b. thuringiensis var. israelensis on larvae of drosophila melanogaster, musca domestica, culicoides sp. and chironomus plumosus are negative except in the last case, but only with doses much higher than those which are lethal for mosquito larvae. tests on mollusks (biomphalaria glabrata) and golden fishes are also negative. the specificity of action of the h 14 serotype, limited to a few diptera families, should be mainly related to the special characteristics of its crystals, whic ...19817249246
generalized transduction in bacillus thuringiensis var. berliner 1715 using bacteriophage cp-54ber.a phage isolated from lysates of phage cp-54 grown on bacillus cereus 569 and selected on the basis of its ability to infect bacillus thuringiensis var. berliner 1715 (serotype i) was designated cp-54ber. phages cp-54ber and cp-54 were similar in size, morphology, cryosensitivity and stabilization by dimethyl sulphoxide. they showed significant differences with regard to inactivation by specific antiserum, adsorption to the berliner strains and host range. phage cp-54ber was able to mediate gene ...19807252480
correlation between specific plasmids and delta-endotoxin production in bacillus thuringiensis. 19817267811
[ph variations in the midgut of aedes aegypti in relation to bacillus thuringiensis var. israelensis (serotype h14) crystal intoxication].after feeding aedes aegypti larvae with b. thuringiensis var. israelensis crystals the very alkaline ph (greater than or equal to 10) of the anterior midgut remains stable during the first twenty minutes, in spite of important cytological damage. thereafter, the ph drops to surround the neutrality and the death occurs. these results are discussed according to the knowledge on the action of b. thuringiensis var. israelensis.19817296735
[innocuousness of bacillus thuringiensis var. israelensis for the larvae of oysters]. 19817296737
bacillus thuringiensis distribution in soils of the united states.during a 2-year study, samples of various types of soils were collected from 115 fields that had not previously been tested with bacillus thuringiensis and which were remote from any large-scale aggregations of lepidopterous insects in rearing or grain-storage areas. an average of about 400 isolates were examined from each soil, and, of 46 373 isolates examined, only 250 (0.5%) were identified as b. thuringiensis. while it was almost impossible to insure that a field had never been treated with ...19817306875
[bactericidal activity of the dye erio acid red xb 400 towards bacillus thuringiensis].laboratory and field tests revealed that the addition of erio acid red xb 400 dye (ear) to bacillus thuringiensis formulations inhibited spores of the bacillus. in the laboratory, 74% of the spores present in a suspension containing 16 x 10(9) viable spores/ml, and 0.25 gm/l of ear, were inhibited after 28 h. spore inactivation in a physiological solution containing 1 x 10(7) viable spores/ml was 75% after the same period of exposure to the same ear concentration. field tests showed a reduction ...19817306883
[sensitization and hyposensitization to bac. thuringiensis]. 19817308791
[safety of the use of the serotype h-14 of bacillus thuringiensis for the non-target fauna of the mosquito breeding places of the french mediterranean coast]. 19807312401
[immediate larvicidal activity and residual action of the endotoxin of the serotype h-14 of bacillus thuringiensis in 2 mosquito biotopes on the french mediterranean coast].the primary powder r.153.78 of the serotype h.14 of b. thuringiensis has been evaluated in small field plots against larvae of ae. detritus and cx. pipiens.. the minimal concentration of the primary powder inducing a complete mortality was 0.1 mg/1 against ae. detritus and 0,4 mg/1 against cx. pipiens, corresponding at dosages of respectively about 310-420 and 1240-1680 international toxic units per litre. the residual larvicide effectiveness was close to nil in spite of the chemical stability o ...19807312402
[activity of the serotype h-14 of bacillus thuringiensis against the principal species of anthropophilic mosquitoes of the french mediterranean coast]. 19807312403
[detection of thermolabile exotoxin in b. thuringiensis and its separation from phospholipase c]. 19817315023
[toxicity of bacillus thuringiensis var. israelensis serotype hi4, for larvae of sandflies, the leishmaniasis vectors (author's transl)]. 19817318051
relative activity of bacillus thuringiensis var. kurstaki and b. thuringiensis var. israelensis against larvae of aedes aegypti, culex quinquefasciatus, trichoplusia ni, heliothis zea, and heliothis virescens. 19817320315
[experiments to inactivate the entomopathogenic action of the preparation dipel in the silkworm bombyx mori l].experiments were carried out at the vivarium of the silkworm experimental station in vratsa during the autumn silkworm feeding in 1980, using the kinshu x showa hybrid. tested was its tolerance of a water solution of chlorinated lime with active chlorine from 0.003 to 1.0 per cent administered orally with the feed. studied was at the same time the inactivating capacity of these chlorine solutions with regard to 0.3 per cent water solutions of dipel in less than a minute's time, the latter being ...19817324378
isolation of a protein from the parasporal crystal of bacillus thuringiensis var. kurstaki toxic to the mosquito larva, aedes taeniorhynchus. 19817332548
patterns of plasmid dna in crystalliferous and acrystalliferous strains of bacillus thuringiensis. 19807335824
[sanitary microbiological standards for bac. thuringiensis, a producer of bacterial insecticides, in plant products].survival of bac. thuringiensis, producers of bacterial insecticides in plant products, was studied in the process of culinary and technological treatment (thermal treatment, preservation, etc.), depending on the extent of dissemination of plant raw material, type of the plant product and pattern of culinary treatment. a study was also made of the viability of the above species in finished products and dishes exposed to varying storage temperatures. according to the data obtained, the use of plan ...19807405137
sporeless mutants of bacillus thuringiensis. iii. the process of crystal formation.in order to investigate the formation of the parasporal crystal of b. thuringiensis with special reference to the spore, sequential ultrastructural analysis of sporulation was performed using a sporeless mutant strain (sp-) as well as its parent wild strain (sp+). from the logarithmic growth to the end of forespore formation, the same sequential process of sporulation proceeded in both strains and a forespore with double membranes appeared. thereafter, subsequent sporulation in the sp- strain wa ...19807414596
bacillus thuringiensis parasporal crystal toxin: dissociation into toxic low molecular weight peptides. 19807417316
purification and properties of phosphatidylinositol-specific phospholipase c of bacillus thuringiensis.a phosphatidylinositol-specific phospholipase c was purified from the culture broth of bacillus thuringiensis to a homogeneous state as indicated by polyacrylamide gel electrophoresis. specific activity of purified enzyme was 312 units/mg, and the recovery of the enzyme activity was 27.2%. the purified enzyme (molecular weight: 23 000 +/- 1000) was maximally active at ph 7.5 and not influenced by edta. the enzyme specifically hydrolyzed phosphatidylinositol, but did not act on phosphatidylcholin ...19807417468
purification of the insecticidal toxin in crystals of bacillus thuringiensis.crystals were purified from four serotypes of the insect pathogen bacillus thuringiensis. crystals from these serotypes were similar in amino acid and n-terminal analyses, but differed in their toxicity to two species of lepidoptera and in their immunological properties. toxic polypeptides were obtained following trypsin digestion of solutions of the crystals. in two strains (serotypes 3 and 9) this fraction contained only one polypeptide. similar results were obtained when dissolved crystals we ...19807420053
role of glutamic acid & glutamate dehydrogenase in sporulation of bacillus thuringiensis var. thuringiensis in chemically defined media. 19807450794
a comparison of protein crystal subunit sizes in bacillus thuringiensis.we have employed gel electrophoresis to determine the number and size of the subunits present in the protein crystals from 16 strains of baccillus thuringiensis. the calculated molecular weights (mw) fell into three major categories whose crystals exhibited the following protein banding patterns: type i, high mw only (140 000- 160 000); type ii, both high mw and medium mw (60 000 and 150 000); and type iii, low mw only (40 000 - 50 000). interestingly, the type i and type ii crystals were the ex ...19807459713
comparative biochemistry of entomocidal parasporal crystals of selected bacillus thuringiensis strains.parasporal crystals of bacillus thuringiensis subspp. kurstaki, tolworthi, alesti, berliner, and israelensis were compared by electron microscopy, polyacrylamide gel electrophoresis, amino acid analysis, tryptic peptide mapping, immunological analysis, and insecticidal activity. spore coats also were compared by polyacrylamide gel electrophoresis. b. thuringiensis subsp. israelensis crystals were lethally toxic to mosquito larvae and nontoxic to tobacco hornworm larvae. conversely, crystals from ...19817462158
transformation of bacillus thuringiensis protoplasts by plasmid deoxyribonucleic acid.a method has been developed to transform plasmid deoxyribonucleic acid into protoplasts of the insect pathogen bacillus thuringiensis. protoplasts were formed by treatment of cells with lysozyme. the efficiency of formation of protoplasts was affected by the strain, the media, and the cell density. deoxyribonucleic acid uptake was induced by polyethylene glycol. deoxyribonucleic acid from the staphylococcus aureus plasmid pc194 was used for transformation. although this plasmid could not be isol ...19817462165
effects of the spore-endotoxin complex of a strain of bacillus thuringiensis serovar morrisoni upon triatoma vitticeps (hemiptera: reduviidae) under laboratory conditions. 19947476224
monomers and dimers of acetylcholinesterase in human meningioma are anchored to the membrane by glycosylphosphatidylinositol.amphiphilic monomers and dimers of acetylcholinesterase (ache) and hydrophilic tetramers of butyrylcholinesterase (buche) were released by extracting human meningioma with tris-saline and tris-saline-triton x-100 buffers. the amphiphilic or hydrophilic behavior of the ache and buche forms was assessed by sedimentation analysis, hydrophobic chromatography and triton x-114 phase-partitioning. a significant fraction of the amphiphilic ache species was converted into hydrophilic components by incuba ...19957478260
[characters and insecticidal polypeptide of a new strain of bacillus thuringiensis subsp. kenyae in china].a new strain of bacillus thurinigiensis bt with high toxicity against noctuidae larvae has been screened for many generations since isolated from larvae candle of aphomia gularis in yiyang county, jiangxi province, in china. by comparison and analysis of results of physiological and biochemical test, flagella antigen identification and esterase type, the strain is identified as h4a-4c bt serovar. kenyae. since its crystal protein type and plasmid type are different from those of bt serovar. keny ...19957483588
trehalose and sucrose protect both membranes and proteins in intact bacteria during drying.the microorganisms escherichia coli dh5 alpha and bacillus thuringiensis hd-1 show an increased tolerance to freeze-drying when dried in the presence of the disaccharides trehalose and sucrose. when the bacteria were dried with 100 mm trehalose, 70% of the e. coli and 57% of the b. thuringiensis organisms survived, compared with 56 and 44%, respectively, when they were dried with sucrose. only 8% of the e. coli and 14% of the b. thuringiensis organisms survived drying without the sugars. fourier ...19957486995
isolation and identification of novel toxins from a new mosquitocidal isolate from malaysia, bacillus thuringiensis subsp. jegathesan.a new mosquitocidal bacillus thuringiensis subsp., jegathesan, has recently been isolated from malaysia. parasporal crystal inclusions were purified from this strain and bioassayed against fourth-instar larvae of culex quinquefasciatus, aedes aegypti, aedes togoi, aedes albopictus, anopheles maculatus, and mansonia uniformis. the 50% lethal concentration of crystal inclusions for each species was 0.34, 8.08, 0.34, 17.59, 3.91, and 120 ng/ml, respectively. these values show that parasporal inclus ...19957487029
enhanced production of insecticidal proteins in bacillus thuringiensis strains carrying an additional crystal protein gene in their chromosomes.a two-step procedure was used to place a cryic crystal protein gene from bacillus thuringiensis subsp. aizawai into the chromosomes of two b. thuringiensis subsp. kurstaki strains containing multiple crystal protein genes. the b. thuringiensis aizawai cryic gene, which encodes an insecticidal protein highly specific to spodoptera exigua (beet armyworm), has not been found in any b. thuringiensis subsp. kurstaki strains. the cryic gene was cloned into an integration vector which contained a b. th ...19957487039
domain iii exchanges of bacillus thuringiensis cryia toxins affect binding to different gypsy moth midgut receptors.aminopeptidase-n, purified from gypsy moth (lymantria dispar l.) brush border membrane vesicles, exhibited specific binding to cryiac toxin but not to cryiaa toxin. cryiaa-cryiac hybrid toxins were used to localize the aminopeptidase-n binding region on cryiac. slot blot assays and ligand blot experiments demonstrated that the hybrid toxins which have the residues 451 to 623, comprising essentially domain iii, from cryiac toxin exhibited strong binding to purified aminopeptidase-n and 120 kda br ...19957488105
bacillus thuringiensis cryia(a) insecticidal toxin: crystal structure and channel formation.the activated 65 kda lepidopteran-specific cryia(a) toxin from the commercially most important strain bacillus thuringiensis var. kurstaki hd-1 has been investigated by x-ray diffraction and for its ability to form channels in planar lipid bilayers. its three-dimensional structure has been determined by a multiple isomorphous replacement method and refined at 2.25 a resolution to an r-factor of 0.168 for data with i > 2 delta (i). the toxin is made of three distinct domains. the n-terminal domai ...19957490762
monoclonal antibody developed against a hemolysin of bacillus thuringiensis.a total of five hybridoma cell lines that produced monoclonal antibodies (mab) against a hemolysin (bt-hemolysin) produced by bacillus thuringiensis were established and characterized. all of these monoclonal antibodies reacted similarly not only to bt-hemolysin but also to a hemolysin (bc-hemolysin) produced by b. cereus, suggesting that the two hemolysins are immunologically indistinguishable. the mab developed in this study was also successfully applied for rapid and simple purification of bo ...19957494502
the safety of bacillus species as insect vector control agents. 19947499181
transcriptional regulation of the bacillus thuringiensis subsp. thompsoni crystal protein gene operon.the two predominant polypeptides of the bacillus thuringiensis subsp. thompsoni crystal are encoded by the cry40 and cry34 genes. these crystal protein genes are located in an operon. western analysis (immunoblotting) demonstrated that the operon promoter activity was located in the region upstream of the cry40 gene. the cry34 protein was expressed only when the upstream promoter region was present. the crystal protein genes are the only cistrons in the operon, and they are expressed during spor ...19937504667
tn5401, a new class ii transposable element from bacillus thuringiensis.a new class ii (tn3-like) transposable element, designated tn5401, was recovered from a sporulation-deficient variant of bacillus thuringiensis subsp. morrisoni eg2158 following its insertion into a recombinant plasmid. sequence analysis of the insert revealed a 4,837-bp transposon with two large open reading frames, in the same orientation, encoding proteins of 36 kda (306 residues) and 116 kda (1,005 residues) and 53-bp terminal inverted repeats. the deduced amino acid sequence for the 36-kda ...19947514590
control of aedes albopictus larvae using time-release larvicide formulations in louisiana.the ability of time-release formulations of larvicides and insect growth regulators (igrs) to provide long-term control of aedes albopictus was investigated in the field. larvicides used in the study were bactimos pellets (bacillus thuringiensis var. israelensis, active ingredient) and abate pellets (temephos, active ingredient). the igr altosid (methoprene, active ingredient) was used in pellet and sand formulations. application rates were higher than label recommendations. in a preliminary tes ...19947516963
enhanced cytotoxicity caused by increased dna strand breakage resulting from synergistic potentiation of bleomycin with bacillus thuringiensis subsp. israelensis delta-endotoxin.we previously reported that a 25 kda bacillus thuringiensis subsp. israelensis (bti) delta-endotoxin potentiates the cytotoxicity of bleomycin (blm) in cultured cells. in order to clarify the mechanism involved, we examined the induction of dna strand breakage by blm in the presence of bti toxin. results showed that the increase in strand breakage resulted in enhanced cytotoxicity through the synergistic potentiation of blm with bti toxin.19947521154
membrane-permeabilizing activities of bacillus thuringiensis coleopteran-active toxin cryiiib2 and cryiiib2 domain i peptide.bacillus thuringiensis toxin cryiiib2 exhibits activity against two agriculturally important pests, the colorado potato beetle, leptinotarsa decemlineata, and the southern corn rootworm, diabrotica undecimpunctata. cryiiib2 shows significant structural similarity to colorado potato beetle-active toxin cryiiia, whose crystal structure has been determined elsewhere [j. li, j. carrol, and d. j. ellar, nature (london) 353:815-821, 1991]. a clone limited to the putative 7-alpha-helical bundle domain ...19947527203
the alpha-5 segment of bacillus thuringiensis delta-endotoxin: in vitro activity, ion channel formation and molecular modelling.a peptide with a sequence corresponding to the highly conserved alpha-5 segment of the cry delta-endotoxin family (amino acids 193-215 of bacillus thuringiensis cryiiia [gazit and shai (1993) biochemistry 32, 3429-3436]), was investigated with respect to its interaction with insect membranes, cytotoxicity in vitro towards spodoptera frugiperda (sf-9) cells, and its propensity to form ion channels in planar lipid membranes (plms). selectively labelled analogues of alpha-5 at either the n-terminal ...19947529493
factors regulating cryivb expression in the cyanobacterium--synechococcus pcc 7942.the expression of the larvicidal bacillus thuringiensis subsp. israelensis cryivb gene in cyanobacteria has been suggested to be an effective means of controlling mosquito populations. using a variety of cryivb constructs, in this study we have examined the effect of synechococcus pcc 7942 culture age on intracellular toxin levels and have attempted to determine the mechanisms by which cryivb gene expression is regulated. the data suggest that specific degradation of the cryivb mrna limits toxin ...19957531814
delta-endotoxins induce cation channels in spodoptera frugiperda brush border membranes in suspension and in planar lipid bilayers.membrane potential measurements using a fluorescent dye indicated that two specific toxins active against spodoptera frugiperda larvae (cryic and cryid) cause immediate permeability changes in midgut epithelial brush border membrane vesicles (bbmv). the initial response and the sustained permeability change are cationic, not very k+ selective, and occur at in vivo lethal doses (nm). the toxin response has a different ion selectivity and is more sensitive to ba2+ than the intrinsic cation permeab ...19957533728
comparative analysis of the 16s to 23s ribosomal intergenic spacer sequences of bacillus thuringiensis strains and subspecies and of closely related species.bacillus thuringiensis spacer regions between the 16s and 23s rrnas were amplified with conserved primers, designated 19-mer and 23-mer primers. a spacer region of 144 bp was determined for all of 6 b. thuringiensis strains, 7 b. thuringiensis subspecies, and 11 b. thuringiensis field isolates, as well as for the closely related species bacillus cereus and bacillus anthracis. computer analysis and alignment of nucleotide sequences identified three mutations and one deletion in the intergenic spa ...19957538281
prevalence of bacillus cereus in selected foods and detection of enterotoxin using tecra-via and bcet-rpla.enterotoxigenic bacillus cereus was detected in cooked foods (17), rice noodles (3), wet wheat noodles (2), dry wheat noodles (10), spices (8), grains (4), legumes (11) and legume products (3). one hundred ninety-four (42.3%), 70 (15.3%) and 23 (5.2%) of the 459 presumptive b. cereus colonies isolated from pemba agar were identified as b. cereus, bacillus thuringiensis and b. mycoides, respectively. b. cereus isolates were examined for growth temperature, ph profile and enterotoxin production us ...19957547144
highly insect-resistant transgenic tobacco plants containing both b.t. and cpti genes.the cowpea trypsin inhibitor (cpti) gene was synthesized according to its cdna sequence using dna synthesizer and confirmed by dna sequencing. the cpti gene and modified bacillus thuringiensis (b.t.) delta-endotoxin gene were cotransformed to tobacco explants mediated by agrobacterium tumefaciens. the integrations of b.t and cpti genes were confirmed by pcr and southern hybridization. three kinds of transgenic plants were obtained: (1) containing cpti gene, (2) containing b.t gene, (3) containin ...19957548766
ssp genes and spore osmotolerance in bacillus thuringiensis israelensis and bacillus sphaericus.it was shown previously that spores and vegetative cells of bacillus sphaericus (bf) and bacillus thuringiensis israelensis (bti) are very sensitive to osmotic variations. since spore osmotolerance has been associated with their sasp (small acid soluble spore proteins) content coded by ssp genes, hybridization assays were performed with sspe and sspa genes from b. subtilis as probes and showed that bti and bf strains could lack an sspe-like gene. the b. subtilis sspe gene was then introduced int ...19957549769
irreversible binding kinetics of bacillus thuringiensis cryia delta-endotoxins to gypsy moth brush border membrane vesicles is directly correlated to toxicity.to examine the binding of bacillus thuringiensis delta-endotoxins, cryiaa, cryiab, and cryiac, to lymantria dispar (gypsy moth) brush border membrane vesicles (bbmv), saturation kinetic analyses were conducted according to a two-step interaction scheme [formula: see text] for delta-endotoxin binding to bbmv, rather than the one-step reversible binding presented in prior reports. the order of toxicity of the delta-endotoxins, as measured by the dose required for a 50% inhibition of weight gain (i ...19957559587
mobilization of bacillus thuringiensis plasmid ptx14-3.the bacillus thuringiensis subsp. israelensis (bti) plasmid ptx14-3 has been reported to contain a gene, mob14-3, with considerable homology to genes encoding mobilization proteins from other gram-positive bacteria. we have used the aggregation-mediated conjugation system recently discovered in bti to compare the mobilization kinetics of different derivatives of plasmid ptx14-3. plasmid ptx14-3 has been found to replicate by the rolling-circle mechanism and to contain a locus suppressing the for ...19957568463
bacillus thuringiensis serovar higo (flagellar serotype 44), a new serogroup with a larvicidal activity preferential for the anopheline mosquito.eight strains of bacillus thuringiensis, isolated in japan, formed spherical parasporal inclusions and exhibited low to moderate larvicidal activities for two mosquito species, anopheles stephensi and culex pipiens molestus, but not for another dipteran, telmatoscopus albipunctatus, or two lepidopterans, bombyx mori and hyphantria cunea. the anopheline toxicity (lc50 = 6.3 micrograms ml-1) was > 10 times greater than the activity on the culex mosquito. these strains were assigned to a previously ...19957576527
[change in the bacillus thuringiensis subsp. israelensis plasmid dna spectrum during growth dynamics]. 19957580992
how does bacillus thuringiensis produce so much insecticidal crystal protein? 19957592363
identification, isolation, and cloning of a bacillus thuringiensis cryiac toxin-binding protein from the midgut of the lepidopteran insect heliothis virescens.bacillus thuringiensis toxins are insecticidal to a variety of insect species. the selectivity of the toxins produced by these bacteria is dependent on both the toxin structure and the receptor sites that are present in different insect species. one of these toxins, cryiac, is highly insecticidal to the noctuid pest heliothis virescens. using toxin overlay assay, a 120-kda glycoprotein was identified as a toxin-binding protein. this protein was partially purified, its n-terminal sequence was det ...19957592988
cellular fatty acid analysis of bacillus thuringiensis ssp. israelensis (onr-60a).the cellular fatty acid composition of bacillus thuringiensis ssp. israelensis (b.t.i.) onr-60a was determined by gas-liquid chromatography (glc). isolates of onr-60a were obtained from the bacillus genetic stock center, pasteur institute, and usda culture collections. these isolates were compared to one another and the culture collections differed in the strains that they contained. eleven separate strains of onr-60a were identified, based on fatty acid composition of the cell envelope. the cur ...19957595442
the future of microbial insecticides as vector control agents.insect vectors of human diseases are subject to diseases of their own caused by viruses, bacteria, fungi, protozoans, and nematodes. over the past 30 years, many members of these groups have been evaluated as vector control agents, particularly for mosquito control. most pathogens and nematodes occur primarily in larvae, and are only effective against this stage. the principal candidate control agents studied include iridescent and nuclear polyhedrosis viruses, the bacteria bacillus thuringiensi ...19957595459
tnpi recombinase: identification of sites within tn5401 required for tnpi binding and site-specific recombination.the bacillus thuringiensis class ii transposon tn5401 encodes a recombinase protein, tnpi, that mediates the resolution of cointegrate molecules generated as intermediates during tn5401 transposition by the tnpa transposase. this recombination event requires a specific target site, or internal resolution site, at which tnpi binds and catalyzes the exchange of dna strands. gel mobility shift assays and dnase i footprinting analyses were used to localize the tnpi binding region to the sequence ext ...19957608077
mutagenesis of specificity and toxicity regions of a bacillus thuringiensis protoxin gene.two different 30-nucleotide regions of the cryiac insecticidal protoxin gene from bacillus thuringiensis were randomly mutagenized. one region was within one of seven amphipathic helices believed to be important for the formation of ion channels. there was no loss of toxicity for three test insects by any of 27 mutants, a result similar to that obtained previously for mutations within another such helix. only mutations within a region encoding the central helix have resulted in a substantial num ...19957608080
effect of low temperature on feeding rate of aedes stimulans larvae and efficacy of bacillus thuringiensis var. israelensis (h-14).experiments were conducted to determine the effects of low temperature (0 and 4 degrees c), vs. a high temperature (22 degrees c), on the feeding rate of aedes stimulans larvae, and their susceptibility to bacillus thuringiensis var. israelensis (h-14) (b.t.i.). third-instar ae. stimulans slowed but did not halt feeding at 0 and 4 degrees c compared to 22 degrees c. susceptibility of larvae, as measured by lc50 values, to b.t.i. was highest at 22 degrees c (lc50 = 0.1 ppm), and lower at 4 degree ...19957616175
comparative toxicity of selected larvicides and insect growth regulators to a florida laboratory population of aedes albopictus.five organophosphates (ops) (chlorpyrifos, chlorpyrifos methyl, fenthion, malathion, and temephos), 3 pyrethroids (bifenthrin, cypermethrin, and permethrin), and 2 microbial pesticides (bacillus thuringiensis serovar.israelensis [b.t.i.] and bacillus sphaericus) were tested as larvicides against a florida aedes albopictus population colonized in the laboratory. in addition, 3 insect growth regulators (igrs) (diflubenzuron, methoprene, and pyriproxyfen) were evaluated. all ops, except for malathi ...19957616194
control of anopheles stephensi breeding in construction sites and abandoned overhead tanks with bacillus thuringiensis var. israelensis.bacillus thuringiensis (h-14), strain 164 (bactoculicide) when applied at 1 g/m2 surface area successfully controlled anopheles stephensi breeding in construction sites, abandoned overhead tanks, and curing waters. subsequent to application, no pupal production was observed in these habitats for 3, 18, and 21 days, respectively. based on these findings, inclusion of bactoculicide in the bioenvironmental vector control strategy is suggested and fortnightly spraying in construction sites at 1 g/m2 ...19957616196
denitration of glycerol trinitrate by resting cells and cell extracts of bacillus thuringiensis/cereus and enterobacter agglomerans.a number of microorganisms were selected from soil and sediment samples which were known to have been previously exposed to nitrate ester contaminants. the two most effective bacteria for transforming glycerol trinitrate (gtn) were identified as bacillus thuringiensis/cereus and enterobacter agglomerans. for both isolates, denitration activities were expressed constitutively and gtn was not required for induction. dialysis of cell extracts from both isolates did not affect denitration, which ind ...19957618866
comparison of toxin overlay and solid-phase binding assays to identify diverse cryia(c) toxin-binding proteins in heliothis virescens midgut.the binding proteins, or receptors, for insecticidal bacillus thuringiensis subsp. kurstaki delta-endotoxins are located in the brush border membranes of susceptible insect midguts. the interaction of one of these toxins, cryia(c), with proteins isolated from heliothis virescens larval midguts was investigated. to facilitate the identification of solubilized putative toxin-binding proteins, a solid-phase binding assay was developed and compared with toxin overlay assays. the overlay assays demon ...19957618886
immunohistochemical detection of binding of cryia crystal proteins of bacillus thuringiensis in highly resistant strains of plutella xylostella (l.) from hawaii.we detected binding of insecticidal crystal proteins from bacillus thuringiensis in one susceptible strain and six resistant strains of diamondback moth, plutella xylostella, from hawaii. immunohistochemical tests with tissue sections from larval midguts showed specific binding of cryia(a), cryia(b), and cryia(c) to brush border membranes. cryie, which is not toxic to p. xylostella, did not bind to midgut tissues. larvae from one of the resistant strains ingested extremely high concentrations of ...19957626052
molecular cloning of an insect aminopeptidase n that serves as a receptor for bacillus thuringiensis cryia(c) toxin.the bacillus thuringiensis cryia(c) insecticidal delta-endotoxin binds to a 120-kda glycoprotein receptor in the larval midgut epithelia of the susceptible insect manduca sexta. this glycoprotein has recently been purified and identified as aminopeptidase n. we now report the cloning of aminopeptidase n from a m. sexta midgut cdna library. two overlapping clones were isolated, and their combined 3095-nucleotide sequence contains an open reading frame encoding a 990-residue pre-pro-protein. the n ...19957629076
cry ia(b) transcript formation in tobacco is inefficient.chimaeric pcamv35scry genes direct in tobacco mesophyll protoplasts mrna levels of less than one transcript per cell. we provide evidence that this low cytoplasmic cry ia(b) mrna level is not due to a rapid turnover but rather results from a marginal import flow of cry messenger into the cytoplasm. run-on assays indicate that the frequency of transcription initiation is not limiting. however, the cry precursor mrna carries at least three regions that are recognized as introns. the absence of hig ...19957632920
bacillus cereus and bacillus thuringiensis isolated in a gastroenteritis outbreak investigation.during investigation of a gastroenteritis outbreak in a chronic care institution, norwalk virus was found in stool specimens from two individuals and bacterial isolates presumptively identified as bacillus cereus were isolated from four individuals (including one with norwalk virus) and spice. phage typing confirmed all bacillus clinical isolates were phage type 2. all clinical isolates were subsequently identified as b. thuringiensis when tested as a result of a related study (l. leroux, person ...19957639990
structural analysis of inositol phospholipids from trypanosoma cruzi epimastigote forms.inositol phospholipids (ipl) from epimastigote forms of trypanosoma cruzi have been investigated by metabolic labelling with [3h]palmitic acid and by glc-ms analysis of the lipids obtained from non-labelled parasites. the ipl fraction was separated into phosphatidylinositol (pi) and inositol-phosphoceramide subfractions, the latter accounting for 80-85% of the total ipl. the neutral lipids released from the ipls by pi-specific phospholipase c (pi-plc) from bacillus thuringiensis were analysed by ...19957646454
the cryia(c) receptor purified from manduca sexta displays multiple specificities.the kinetic binding characteristics of four bacillus thuringiensis cryi insecticidal crystal proteins to a cry-binding protein, purified from manduca sexta brush-border vesicles, were analyzed by an optical biosensor. this 120-kilodalton binding protein, previously determined to be aminopeptidase n, was converted to a 115-kilodalton water-soluble form by removing the attached glycosylphosphatidylinositol anchor with phospholipase c. the solubilized form recognized the three major subclasses of c ...19957657602
adhesion and cytotoxicity of bacillus thuringiensis to cultured spodoptera and drosophila cells.two bacillus thuringiensis strains were tested for the ability to adhere to cultured spodoptera and drosophila insect cells. the wild-type strain is virulent and motile and readily adheres to and kills both types of insect cells. the avirulent mutant strain, which lacks flagella and several other of the proposed virulence factors, does not adhere to the insect cells and does not kill these cells efficiently. purified flagella bind to insect cells; addition of anti-flagella serum abolishes cell b ...19957658049
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