Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| [comparison of mosquito larvicidal efficacy between microbial encapsulated bti (ebti) and standard bti (sbti)]. | a comparative study was conducted on the efficacy of mosquito larvicides ebti and sbti. the results showed that: 1. the residual efficacy of ebti was remarkably higher than that of sbti at 0.007-0.002ppm bti concentration (p < 0.01), the mosquito larvae mortality of ebti remained 100% until the 4th week; in contrast, the mosquito larva mortality of sbti gradually and obviously declined from the 2nd to 4th week after treatment (x2 = 8.17-24.08), and reached 0 at the 4th week. 2. the lowest bti co ... | 1992 | 1307279 |
| localized mutagenesis defines regions of the bacillus thuringiensis delta-endotoxin involved in toxicity and specificity. | bacillus thuringiensis produces a variety of delta-endotoxins which bind to specific receptors in insect larval midguts. following insertion into the membrane there is an alteration of ion flux culminating in osmotic lysis. mutagenic oligonucleotides were used to define regions in one of these toxins involved in specificity and toxicity. one region is highly conserved among all toxins sequenced to date and many mutations resulted in loss of toxicity for three test lepidoptera. the mutant toxins ... | 1992 | 1310313 |
| location of a bombyx mori receptor binding region on a bacillus thuringiensis delta-endotoxin. | receptor binding studies were performed with 125i-labeled trypsin-activated insecticidal toxins, cryia(a) and cryia(c), from bacillus thuringiensis on brush-border membrane vesicles (bbmv) prepared from bombyx mori larval midgut. bioassays were performed by gently force feeding b. mori with diluted toxins. cryia(a) toxin (ld50; 0.002 micrograms) was 200 times more active against b. mori larvae than cryia(c) toxin (ld50; 0.421 micrograms) and showed high-affinity saturable binding. the kd and the ... | 1992 | 1310681 |
| the mode of action of bacillus thuringiensis endotoxins. | 1992 | 1311541 | |
| sensitivity to plating of escherichia coli cells expressing the crya gene from bacillus thuringiensis var. israelensis. | the gene (cyta) coding for the 27 kda polypeptide of the bacillus thuringiensis var. israelensis mosquito larvicidal delta-endotoxin, was cloned into a plasmid containing the t7 bacteriophage promoter. the plasmid was used to transform an escherichia coli strain containing the t7 rna polymerase gene 1, under the control of lacp. loss of colony-forming ability without substantial lysis, associated with immediate inhibition of dna synthesis, was observed after induction of transformed cells. the c ... | 1992 | 1313146 |
| effect of phosphatidylinositol-specific phospholipase c from bacillus thuringiensis on solid spinocellular carcinoma. | phosphatidylinositol-specific phospholipase c (piplc) from bacillus thuringiensis (0.11 units per ml) inhibited growth of ic-sofia carcinoma cell line in culture by 64%. the growth of transplanted carcinoma in hamsters was also inhibited by 29% at a dose of 4.9 units of piplc/kg animal/day. in addition, degeneration processes and a significant fibrosis of the tumour occurred. the functional, clinical, biochemical and haematological parameters studied were consistent with the established antitumo ... | 1992 | 1313607 |
| characterization of the ph-mediated solubility of bacillus thuringiensis var. san diego native delta-endotoxin crystals. | native crystals of bacillus thuringiensis var. san diego, a coleopteran-specific delta-endotoxin, were metabolically labelled with [35s]methionine. specific activity was 82,000 cpm/micrograms (2.44 ci/mmol). using a universal buffer formulated with the same ionic strength at every ph, we determined that native crystals dissolve above ph 10 and below ph 4. at the acidic ph, the rate of solubilization was substantially slower than at the alkaline ph. recrystallization rates for the toxin were simi ... | 1992 | 1315528 |
| [site-specific restrictases from bacillus thuringiensis var. kumantoensis]. | the efficiency of bacteriophages cp-54 and cp-55 plating on bacillus thuringiensis var. kumantoensis h18 (kum) is decreased about 10-fold as compared with the efficiency of plating on bacillus thuringiensis var. galleriae h5 (gal). bacteriophages having propagated for one cycle in kum cells might be further grown in this strain without growth restriction. two site-specific restriction enzymes isolated from bacillus thuringiensis var. kumantoensis were designated btki and btkii. the endonuclease ... | 1992 | 1320199 |
| isolation and partial characterization of binding proteins for immobilized delta endotoxin from solubilized brush border membrane vesicles of the silkworm, bombyx mori, and the common cutworm, spodoptera litura. | 1. brush border membrane vesicles (bbmv) were prepared from the bombyx mori, and spodoptera litura, midguts. bbmv was solubilized. 2. activated delta endotoxin from bacillus thuringiensis were immobilized. 3. solubilized bbmv proteins were applied to the toxin column and the proteins bound were analyzed by sds-page. 4. in the case of b. mori m(r) = 220,000, 150,000 and 130,000 and in the case of s. litura 160,000 bands were detected. 5. the bindings were inhibited by n-acetyl galactosamine and m ... | 1992 | 1323444 |
| acetylcholinesterases of the nematode steinernema carpocapsae. characterization of two types of amphiphilic forms differing in their mode of membrane association. | we analyzed the molecular forms of acetylcholinesterase (ache) in the nematode steinernema carpocapsae. two major aches are involved in acetylcholine hydrolysis. the first class of ache is highly sensitive to eserine (ic50 = 0.05 microm). the corresponding molecular forms are: an amphiphilic 14s form converted into a hydrophilic 14.5s form by mild proteolysis and two hydrophilic 12s and 7s forms. reduction of the amphiphilic 14s form with 10 mm dithiothreitol produces hydrophilic 7s and 4s forms ... | 1992 | 1323459 |
| [modification and expression of insecticidal protein structural gene of bacillus thuringiensis var. aizawai 7-29]. | the regulative region (181bp) and the fifth toxic active domain (217bp) were removed from the insecticidal protein gene of bacillus thuringiensis var. aizawai 7-29. after the synthesis of the adaptor (15bp) that contains initiation codon (atg) and the pcr synthesis of the fifth toxic active domain (229bp) that contains stop codon (taa), were inserted into on 5' truncated and 3' truncated of the coding fod n-terminal peptid's dna fragment, that to become a modified structural gene. the modified s ... | 1992 | 1323897 |
| is231d, e and f, three new insertion sequences in bacillus thuringiensis: extension of the is231 family. | is231 constitutes a family of insertion sequences widespread among bacillus thuringiensis subspecies. three new is231 variants have been isolated from b. thuringiensis subspecies finitimus (is231 d and e) and israelensis (is231f). like the previously described is231a, b and c, these 1.7 kb elements display single open reading frames encoding 477/478-amino-acid proteins which share between 72% and 88% identity with those of the other members of the family. sequence comparisons also reveal that al ... | 1992 | 1324390 |
| genomic amplification and expression of delta-endotoxin fragment of bacillus thuringiensis. | delta-endotoxin gene of bacillus thuringiensis hd-1 var kurstaki codes for the insecticidal crystal protein (icp) specific for lepidopteran insects. since the n-terminal half of the toxin is sufficient both for insect specificity and toxicity, the coding sequence of this part of the gene cryia(b) was amplified by pcr and cloned in puc19. as there was no expression of immunologically detectable delta-endotoxin in this clone in e. coli, the amplified icp gene was transferred to an expression vecto ... | 1992 | 1326952 |
| substrate stereospecificity of phosphatidylinositol-specific phospholipase c from bacillus cereus examined using the resolved enantiomers of synthetic myo-inositol 1-(4-nitrophenyl phosphate). | the substrate stereospecificity of phosphatidylinositol-specific phospholipase c from bacillus cereus is examined using the resolved optical isomers of synthetic myo-inositol 1-(4-nitrophenyl phosphate), a chromogenic substrate for the phospholipase. the synthetic route employs mild acid-labile protecting groups and separation of the substituted myo-inositol enantiomers as the (-)-camphanyl ester diastereomers. measurements of the initial rates of cleavage of the d and l enantiomers of the nitro ... | 1992 | 1327107 |
| effects of ph on conformational properties related to the toxicity of bacillus thuringiensis delta-endotoxin. | the delta-endotoxin of bacillus thuringiensis subspecies kurstaki is an intracellular crystalline proteinaceous inclusion which, upon ingestion, is toxic to lepidopteran insects. upon dissolution at ph > 9 it yields a protein subunit called protoxin. under appropriate conditions, protoxin is hydrolyzed to a toxin molecule, which is responsible for killing the insect. it is known that this toxic activity decreases considerably above ph 10. in this study, circular dichroism spectroscopy has been u ... | 1992 | 1327158 |
| processing of delta-endotoxin from bacillus thuringiensis subsp. kurstaki hd-1 and hd-73 by gut juices of various insect larvae. | midgut juices were prepared from adoxophyes sp., smaller tea tortrix (stt); bombyx mori, silkworm (sw); spodoptera litura, common cutworm (ccw); plutella xylostella, diamondback moth (dbm); and musca domestica, housefly (hf) and immobilized onto sepharose 4b. delta-endotoxins (icps) from bacillus thuringiensis subsp. kurstaki hd-1 and hd-73 were digested by these immobilized gut juice proteases. all gut juices tested derived relatively proteolytic resistant cores from icp. the molecular sizes of ... | 1992 | 1328398 |
| the delta-endotoxin protein family displays a hydrophobic motif that might be implicated in toxicity. | a computer-based analysis of hydropathy and surface probability of representative members of each class of the cry family of proteins was performed. a highly conserved hydrophobic motif within the previously described block, d2, is present not only in lepidopteran toxin genes but also in toxins active against diptera and coleoptera. an interesting feature of this hydrophobic motif is the presence of an aspartic residue (highly hydrophilic) in its middle part. comparison with the amino acid seque ... | 1992 | 1328811 |
| purification and crystallization of insecticidal delta-endotoxin cryiiib2 from bacillus thuringiensis. | cryiiib2, an insecticidal protein from bacillus thuringiensis has been crystallized from 0.6 m nabr and hepes buffer at ph 7.0 and x-ray diffraction data collected on a native crystal to 2.4 a. the insecticidal protein was obtained from a bacillus thuringiensis (bt) strain eg7231. crystals of the endotoxin are orthorhombic, space group c2221, with unit cell dimensions of a = 122.44, b = 131.81, and c = 105.37 a. a unit cell contains one molecule of the 67,000 da endotoxin per asymmetric unit. | 1992 | 1329083 |
| glycolipid-anchored acetylcholinesterases from rabbit lymphocytes and erythrocytes differ in their sensitivity to phosphatidylinositol-specific phospholipase c. | the type of membrane association of acetylcholinesterase (ache, ec 3.1.1.7) was studied in rabbit lymphocytes and erythrocytes. in both cases, the unique ache molecular form was an amphiphilic dimer (referred to as g2a) anchored in the membrane by a glycosylphosphatidylinositol. in lymphocytes, g2a ache was directly converted into its hydrophilic g2h counterpart by a treatment with bacillus thuringiensis phosphatidylinositol-phospholipase c (pi-plc, ec 3.1.4.10). in erythrocytes, ache was resist ... | 1992 | 1329966 |
| tetracycline enhances tn916-mediated conjugal transfer. | pregrowth of the donor on medium containing tetracycline increased conjugative transposition of tn916 and the transposon-dependent mobilization of pc194 19- to 119-fold in matings between bacillus subtilis and bacillus thuringiensis subsp. israelensis. tn916 and pc194 transferred independently under these conditions. when enterococcus faecalis was the donor and b. thuringiensis subsp. israelensis the recipient, pregrowth in tetracycline increased the conjugative transposition frequency by approx ... | 1992 | 1334267 |
| structural comparisons between the soluble and the gpi-anchored forms of the paramecium temperature-specific 156g surface antigen. | biosynthetic labelling experiments performed on p primaurelia strain 156, expressing the temperature-specific g surface antigen, 156g sag, demonstrated that the purified 156g sag contained the components characteristic of a gpi-anchor. [3h]ethanolamine, [3h]myo-inositol, [32p]phosphoric acid and [3h]myristic acid could all be incorporated into the surface antigen. myristic acid labelling was lost after treatment in vitro with bacillus thuringiensis phosphatidylinositol-specific phospholipase c ( ... | 1992 | 1335331 |
| [morphology and delta-endotoxin proteins of bacillus thuringiensis from soils and their toxicities to insects]. | 94 strains of bacillus thuringiensis were isolated from soils in southwest and northwest of china. the morphology of cells, spores and parasporal crystals of these strains was investigated under transmission and scanning electro-microscope. proteins of delta-endotoxins from all strains were analysed by rapid sds-page. 9 species of insects in lepidoptera, coleoptera and diptera were tested for assay of delta-endotoxins. some kinds of parasporal crystals were quite different in form and in composi ... | 1992 | 1338553 |
| characterization and properties of a novel plasmid vector for bacillus thuringiensis displaying compatibility with host plasmids. | a novel plasmid vector, composed of a 1.7-kb bacillus thuringiensis (b.t.) replicon, a multiple cloning site, and an erythromycin-resistance marker gene from bacillus subtilis, was constructed for use in b.t. unlike other vectors which have been reported to be acceptable for b.t., this new b.t. vector was stably maintained in the absence of er and did not displace host plasmids, some of which carry crystal protein-encoding genes (cry genes). the compatibility of this b.t. vector with native plas ... | 1992 | 1339372 |
| isolation and partial purification of cytochrome oxidases from bacillus thuringiensis subsp. israelensis hd-567. | analyses of the cell membrane fractions by spectral absorbance revealed the presence of cytochrome c and three cytochrome oxidases in bacillus thuringiensis subsp. israelensis hd-567-cytochromes a+a3, d, and o. a modified procedure was used to purify the cytochrome c:o complex from this organism. the oxidase complex was first solubilized from a sonic-disrupted cell membrane fraction (r3 fraction) using deoxycholate and kcl. the resulting soluble fraction was further purified by sephadex g-50 gel ... | 1992 | 1341999 |
| a new serotype of bacillus thuringiensis from colombia toxic to mosquito larvae. | during a survey conducted in colombia a new isolate of bacillus thuringiensis that showed toxicity toward culex quinquefasciatus, cx. pipiens, aedes aegypti, and anopheles stephensi larvae was isolated. parasporal crystals were spherical in shape and showed a great degree of similarity with those produced by the reference strain of bacillus thuringiensis subsp. israelensis. supernatant fraction of the whole culture was not toxic, and heat-stable exotoxin production was negative. catalase, urease ... | 1992 | 1347310 |
| the parasporal inclusion of bacillus thuringiensis subsp. shandongiensis: characterization and screening for insecticidal activity. | the parasporal body of bacillus thuringiensis subsp. shandongiensis was characterized in terms of its structure, protein composition, and toxicological properties against several types of insects. the crystals of b. thuringiensis shandongiensis appear to consist of a major protein of 144 kda present in an spherical inclusion, as determined by transmission electron microscopy, titration curve analysis, and sds-page of the solubilized crystals. a second protein of ca. 60 kda is present in trace am ... | 1992 | 1351504 |
| biological control of mosquitoes and other biting flies by bacillus sphaericus and bacillus thuringiensis. | 1992 | 1352283 | |
| involvement of a possible chaperonin in the efficient expression of a cloned cryiia delta-endotoxin gene in bacillus thuringiensis. | the bacillus thuringiensis cryiia delta-endotoxin gene is found as the third-gene in a three-gene operon, with a sporulation-dependent promoter lying upstream of the first gene, orf1. we show here that the polypeptide product of the middle gene (orf2) is required for efficient expression of the toxin gene. in the absence of a functional orf2 polypeptide the toxin does not form the crystalline inclusions characteristic of other known bacillus thuringiensis toxins. we discuss the importance of thi ... | 1992 | 1352615 |
| [the efficacy of a combined preparation based on bacillus sphaericus and bac. thuringiensis h-14 against the larvae of blood-sucking mosquitoes]. | the optimal bactoculicide/sphaerolarvicide ratio in combination using against aedes aegypti larvae was established in laboratory by selection. the field trials of the selected bs/bt sample containing the ingredients in titer: bactoculicide-83, sphaerolarvicide-17 were conducted in the arid area of central asia. with 1 g/m2, complete mortality of culex, aedes and anopheles larvae was obtained with the residual larvicidal action of 15 days. it is recommended to carry out more large-scale trials of ... | 1992 | 1354836 |
| comparison of bacillus thuringiensis subsp. israelensis cryiva and cryivb cloned toxins reveals synergism in vivo. | when the gene for the mosquitocidal protein cryiva was expressed in two strains of bacillus thuringiensis (bt) cured of their resident delta-endotoxin genes, the protein accumulated as large inclusions. the inclusions produced in the bt subsp. kurstaki recipient strain were twice as soluble at alkaline ph as the inclusions produced in bt subsp. israelensis. solubilized protoxins were activated by treatment with mosquito gut extracts or trypsin for varying lengths of time and tested for in vitro ... | 1992 | 1355748 |
| a broad-spectrum cytolytic toxin from bacillus thuringiensis var. kyushuensis. | bacillus thuringiensis (bt) var. kyushuensis synthesizes a mosquitocidal crystalline inclusion containing several proteins ranging from 140 to 14 kda. we have identified a 25 kda protein protoxin in this inclusion which is not cytolytic, but when activated proteolytically to 23-22 kda products is cytolytic to mosquito, lepidopteran and mammalian cells, can release entrapped glucose from liposomes and forms cation-selective channels in a planar lipid bilayer. this broad-spectrum cytolytic toxin i ... | 1992 | 1355907 |
| host range of clostridium bifermentans serovar. malaysia, a mosquitocidal anaerobic bacterium. | clostridium bifermentans serovar. malaysia (c.b.m.) is toxic to mosquito larvae. in this study, we quantified its toxicity to the mosquitoes, aedes aegypti, ae. albopictus, ae. caspius, ae. detritus, anopheles stephensi, an. gambiae, culex pipiens and cx. quinquefasciatus. anopheles larvae are the most susceptible, followed by ae. detritus and ae. caspius, then culex and other aedes larvae. according to mosquito species, the lc50 varies from 7 x 10(3) to 1.3 x 10(6) cells/ml. three concentration ... | 1992 | 1357087 |
| factors influencing the activity of bacillus thuringiensis var. israelensis treatments. | environmental factors influence the effectiveness of microbial control agents in mosquito control programs. four of these factors (water temperature, larval density, sunlight and the effect of associated filter feeders) were studied with bacillus thuringiensis var. israelensis under laboratory and semifield conditions in europe using different instars of aedes vexans, ae. aegypti and culex pipiens. bioassays conducted at a low temperature (5 degrees c) yielded 10-fold higher lc50 and lc90 values ... | 1992 | 1357088 |
| toxicity and residual action of the photoactivated compound, cyano-alpha-terthienyl, and its efficacy for reducing pre-imaginal populations of mosquitoes. | the photoactivated compound, cyano-alpha-terthienyl (cyano-alpha-t), was highly toxic to pre-imagines of the mosquitoes culex restuans, cx. tarsalis and culiseta inornata when synergized with piperonyl butoxide (pbo). lethal concentrations for 50% mortality, determined during an outdoor trial using caged fourth-instar culex spp. larvae, were 19.4, 15.4 and 12.9 g/ha at 24, 48 and 72 h after treatment, respectively. no residual activity of cyano-alpha-t was observed beyond 24 h following treatmen ... | 1992 | 1359007 |
| t cell maturation stage-linked heterogeneity of the glycosylphosphatidylinositol membrane anchor of thy-1. | we showed that some of thy-1 molecules on murine thymocytes are resistant to phosphatidylinositol-specific phospholipase c (pi-plc) derived from bacillus thuringiensis. both immature thymocytes with low cd3 expression and mature thymic t lymphocytes with high cd3 expression carried the pi-plc-resistant thy-1, and the pi-plc-sensitivity of thy-1 extensively varied among thymocyte subpopulations. in contrast, the same pi-plc fully hydrolysed the anchor of thy-1 on peripheral t lymphocytes. when th ... | 1992 | 1360444 |
| sensitivity of mosquito-pathogenic bacterial strains to various antibodies. | four strains of bacillus sphaericus, 1593, 2362, 9001 and 9002, b. thuringiensis h-14 and b. thuringiensis neoleonensis were tested for sensitivity against 18 antibiotics. the results revealed that all the four strains of b. sphaericus are resistant to colistin, nalidixic acid, polymyxin b and streptomycin. however, b. thuringiensis h-14 was resistant to 9 antibiotics, viz. ampicillin, cephalexin, carbenicillin, co-trimoxazole, colistin, cloxacillin, penicillin, nitrofurantoin and polymyxin b wh ... | 1992 | 1363415 |
| [an evaluation of the genotoxicity activity of the microbial preparation bulmoscide]. | the genotoxic activity of the microbial preparation bulmoscid "in vivo" for somatic cells of mammals is studied by micronucleus method in marrow of mice. the experiments are performed on inbred mice c57bl6 of both sexes at unrepeated oral introduction of the preparation in two doses: 2200 mg/kg-1 (2.64.10(10) cells kg-1), and 1100 mg/kg-1 (1.32.10(10) cells kg-1) presenting 80% and respectively 40% of the unrepeated maximum tolerable dose of "bulmoscid" for mice (2750 mg/kg-1). the genotoxic ind ... | 1992 | 1364531 |
| [the acute toxicity of the microbial preparation bulmoscide]. | the acute toxicity of a new bulgarian microbial preparation bulmoscid on the basis of bacillus thuringiensis h-14 in the conditions of oral, dermal, inhalation and intraperitoneal introduction in experimental animals is determined. the assessment of toxicity is made by using toxicometric, integral, hematologic, histologic and microbiologic methods in accordance with bulgarian and international criteria and standards. it is established, that the preparation bulmoscid introduced orally in dose 550 ... | 1992 | 1364532 |
| broad-spectrum resistance to bacillus thuringiensis toxins in heliothis virescens. | evolution of pest resistance to insecticidal proteins produced by bacillus thuringiensis (bt) would decrease our ability to control agricultural pests with genetically engineered crops designed to express genes coding for these proteins. previous genetic and biochemical analyses of insect strains with resistance to bt toxins indicate that (i) resistance is restricted to single groups of related bt toxins, (ii) decreased toxin sensitivity is associated with changes in bt-toxin binding to sites in ... | 1992 | 11607319 |
| managing insect resistance to bacillus thuringiensis toxins. | bacillus thuringiensis (b.t.) delta-endotoxins provide an alternative to chemical insecticides for controlling many species of pest insects. recent biotechnological developments offer the promise of even greater use of b.t. toxins in genetically transformed pest-resistant crops. however, the discovery that insects can adapt to these toxins raises concerns about the long-term usefulness of b.t. toxins. several methods for managing the development of resistance to b.t. toxins have been suggested, ... | 1992 | 17755107 |
| construction of novel bacillus thuringiensis strains with different insecticidal activities by transduction and transformation. | the shuttle vector pht3101 and its derivative pht408, bearing a copy of a cryia(a) delta-endotoxin gene, were transferred into several bacillus thuringiensis subspecies through phage cp-54ber-mediated transduction, with frequencies ranging from 5 x 10 to 2 x 10 transductant per cfu, depending on the strain and on the plasmid. in cry and cry native recipients, the introduction of the cryia(a) gene resulted in the formation of large bipyramidal crystals that were active against the insect plutella ... | 1992 | 16348674 |
| distribution, frequency, and diversity of bacillus thuringiensis in an animal feed mill. | bacillus thuringiensis was isolated from 36 of 50 residue samples obtained from an animal feed mill (a stored-product environment). of 710 selected colonies having bacillus cereus-b. thuringiensis morphology isolated from the samples, 477 were classified as b. thuringiensis because of production of parasporal delta-endotoxin crystals. there was a diverse population of b. thuringiensis, as revealed by differentiation of the isolates into 36 subgroups by using (i) their spectra of toxicity to the ... | 1992 | 16348699 |
| perspectives on the bacterial control of vectors in the tropics. | biological agents have not found wide application in the control of insects that transmit agents of human disease. fungal pathogens may have a potential for field use, but environmental constraints, lack of knowledge of their life cycle, or dependence on production in vivo, have prevented their widespread use. in fact, sporogenous bacteria are the only biological agents used on a large scale for the control of mosquitoes and blackflies that transmit diseases in the tropics. two bacteria, bacillu ... | 1992 | 15463539 |
| resistance to toxins from bacillus thuringiensis subsp. kurstaki causes minimal cross-resistance to b. thuringiensis subsp. aizawai in the diamondback moth (lepidoptera: plutellidae). | repeated exposure in the field followed by laboratory selection produced 1,800- to >6,800-fold resistance to formulations of bacillus thuringiensis subsp. kurstaki in larvae of the diamondback moth, plutella xylostella. four toxins from b. thuringiensis subsp. kurstaki [cryia(a), cryia(b), cryia(c), and cryiia] caused significantly less mortality in resistant larvae than in susceptible larvae. resistance to b. thuringiensis subsp. kurstaki formulations and toxins did not affect the response to c ... | 1993 | 16348929 |
| biotinylation of bacillus thuringiensis insecticidal crystal proteins. | biotinylation of bacillus thuringiensis insecticidal crystal proteins (icps) was evaluated for its potential use in an alternative icp screening method and in the characterization of icp receptors. in vivo biological activity of cryia(b), as inferred from bioassays with manduca sexta and ostrinia nubilalis and from histopathological effects on o. nubilalis midgut cells induced by force feeding, was not affected by biotinylation at moderate biotinylation ratios. a competitive radioreceptor assay ... | 1993 | 16348959 |
| two different bacillus thuringiensis delta-endotoxin receptors in the midgut brush border membrane of the european corn borer, ostrinia nubilalis (hübner) (lepidoptera: pyralidae). | binding of three bacillus thuringiensis insecticidal crystal proteins (icps) to the midgut epithelium of ostrinia nubilalis larvae was characterized by performing binding experiments with both isolated brush border membrane vesicles and gut tissue sections. our results demonstrate that two independent icp receptors are present in the brush border of o. nubilalis gut epithelium. from competition binding experiments performed with i-labeled and native icps it was concluded that cryia(b) and cryia( ... | 1993 | 16348960 |
| nonenzymatic glycosylation of lepidopteran-active bacillus thuringiensis protein crystals. | we used high-ph anion-exchange chromatography with pulsed amperometric detection to quantify the monosaccharides covalently attached to bacillus thuringiensis hd-1 (dipel) crystals. the crystals contained 0.54% sugars, including, in decreasing order of prevalence, glucose, fucose, arabinose/rhamnose, galactose, galactosamine, glucosamine, xylose, and mannose. three lines of evidence indicated that these sugars arose from nonenzymatic glycosylation: (i) the sugars could not be removed by n- or o- ... | 1993 | 16349021 |
| expression of cryiva and cryivb genes, independently or in combination, in a crystal-negative strain of bacillus thuringiensis subsp. israelensis. | the cryiva and cryivb genes, encoding the 125- and 135-kda proteins, respectively, of bacillus thuringiensis subsp. israelensis, were cloned either alone or together into a shuttle vector and expressed in a nontoxic strain of b. thuringiensis subsp. israelensis. the cryivb protein was produced at a high level during sporulation and accumulated as inclusions; in contrast, the cryiva polypeptide did not form such structures unless it was cloned on a higher-copy-number plasmid. transcriptional fusi ... | 1993 | 16349095 |
| production of bacillus thuringiensis spores in total cell retention culture and two-stage continuous culture using an internal ceramic filter system. | the production of bacillus thuringiensis spores was investigated in a bioreactor incorporating a ceramic membrane filter to improve spore concentration and volumetric productivity. two cultivation methods were used in this study: a total cell retention culture (tcrc), and a two-stage continuous culture with partial cell bleeding. in the tcrc, fed by 50 g/l of glucose, a spore concentration of 1.6 x 10(10) cfu/ml was obtained with a spore percentage of greater than 95% and a maximum cell mass of ... | 1993 | 18613240 |
| recent advances in vector control in filariasis. | three factors are involved when vector control is incorporated into an integrated control program for filariasis: (1) the vector species or species complex of each filarial worm; (2) type of control measures employed; (3) pesticide application. recent advances in vector control in filariasis include the use of bed nets, environmental manipulation, insecticides and biological control. three promising advances in vectrol control are the use of pathogenic bacteria such as bacillus thuringiensis h-1 ... | 1993 | 7973950 |
| [laboratory studies of the usefulness of biopreparation dipel in reducing the german cockroach (blattella germanica l.) population]. | in the studies conducted for finding of biological factors effectively controlling insects of hygienic importance german cockroaches were subjected to the action of an insecticide containing spores of bacillus thuringiensis var. kurstaki. one gram of the insecticide contained 25 miliard (us billion) spores with protein endotoxin crystals. the insects were given drinking water and food containing 1.0%, 0.5%, 0.25%, 0.125% of the initial preparation. the experiment was carried out on 1800 cockroac ... | 1993 | 8016546 |
| [the nature of the interrelations of different bacillus thuringiensis serotypes between themselves and other species of the genus bacillus]. | intraspecies interrelations between representatives of 7 serotypes of bacillus thuringiensis, as well as antagonistic interrelations between b. thuringiensis and 130 strains of 16 species of bacillus bacteria were studied. antagonistic activity was determined for 18 strains, representatives of genus bacillus, with respect to b. thuringiensis var. tuviensis. antagonism was the most pronounced between the strains of the alesti serotype and representatives of other serotypes as well as between the ... | 1993 | 8025694 |
| [the suitability of bacterial preparations intended for mosquito control in salt water]. | laboratory experiments have brought the authors to a conclusion on the efficacy of b. thuringiensis and b. sphaericus-based insecticides in salty water mosquito breeding sites. species difference of mosquito larvae susceptibility to the insecticides related to salt concentration in water were detected. | 1993 | 8041317 |
| insect tolerance of transgenic populus nigra plants transformed with bacillus thuringiensis toxin gene. | leaves and stem segments of populus nigra were transformed with a. tumefaciens lba4404 harboring a binary vector containing chimeric genes of npt and 35s-omega-b.t. toxin-nos. nineteen regenerated kanamycin resistant plants were analyzed by dna hybridization, out of which 10 were shown to be the candidates of transgenic plants. insect tolerance tests showed that the transgenic plants were toxic to two lepidopteran pests, lymantria dispar l. and apocheimia cinerarius erschoff. based on the result ... | 1993 | 8061230 |
| [hygienic standardization of biological insecticide contents and biological factory waste in soil]. | 1993 | 8063150 | |
| tolerance of sewage treatment plant microorganisms to mosquitocides. | beneficial protozoa and rotifers collected from a wastewater treatment plant in panama city, fl, were tested for tolerance to 11 commonly used mosquito larvicides and adulticides in the laboratory. the acute effects were assessed using selected concentrations of the adulticides fenthion, malathion, naled, permethrin, and resmethrin; and the larvicides bacillus thuringiensis israelensis, bacillus sphaericus, diflubenzuron, larviciding oil, methoprene, and temephos for the following microorganism ... | 1993 | 8126488 |
| [actual and potential possibilities of using delta-endotoxins of bacillus spp. for control of harmful and nuisance insects]. | 1993 | 8128722 | |
| experimental study of subacute oral, dermal and inhalation toxicity of bulmoscide preparation. | the purpose of this study is to give the toxicological characteristics of subacute oral, dermal and inhalation exposure of microbial preparation bulmoscide, which is based on bacterium bacillus thuringiensis, serotype h-14. the study was performed on sexually mature wistar rats of both sexes. no significant changes in non-specific, clinico-laboratory and biochemical parameters as well as morphological examinations in any tested groups compared to the control groups were revealed. the doses 110 m ... | 1993 | 8219894 |
| cloning, expression, and mutagenesis of phosphatidylinositol-specific phospholipase c from staphylococcus aureus: a potential staphylococcal virulence factor. | staphylococcus aureus secretes a phosphatidylinositol (pi)-specific phospholipase c (pi-plc) which is able to hydrolyze the membrane lipid pi and membrane protein anchors containing glycosyl-pi. the gene for pi-plc (plc) was cloned from s. aureus into escherichia coli. oligonucleotide probes based on partial protein sequence and polyclonal antibodies raised against the purified protein were used to identify positive clones. e. coli transformed with a plasmid containing the plc gene expressed pi- ... | 1993 | 8225585 |
| expression of full-length and truncated forms of crystal protein genes from bacillus thuringiensis subsp. kurstaki in a baculovirus and pathogenicity of the recombinant viruses. | full-length and truncated forms of the crystal protein gene cryia(b) derived from bacillus thuringiensis subsp. kurstaki hd-1 and full-length cryia(c) gene of b. thuringiensis subsp. kurstaki hd-73 were introduced into the genome of the baculovirus autographa californica nuclear polyhedrosis virus, in place of the polyhedrin gene. all gene constructs were expressed at high levels in insect cells and insects upon infection with the recombinant viruses. the protein products were shown to be biolog ... | 1993 | 8228317 |
| protection from ultraviolet irradiation by melanin of mosquitocidal activity of bacillus thuringiensis var. israelensis. | a process for production, isolation, and purification of melanin produced by the fermentation of streptomyces lividans 66 harboring a recombinant plasmid pij702-bearing tyrosinase gene has been developed. the efficacy of melanin in the protection of mosquito larvacidal activity of bacillus thuringiensis var. israelensis against uv light has been studied. results obtained by the live cell counts and the bioassay of residual mosquitocidal activity of b. thuringiensis var. israelensis after exposur ... | 1993 | 8228318 |
| fine mapping and dna sequence of replication functions of bacillus thuringiensis plasmid ptx14-3. | ptx14-3 is a 7.5-kb cryptic plasmid isolated from a bacillus thuringiensis subspecies israelensis strain. like many other small plasmids in gram-positive bacteria, ptx14-3 replicates via a single-stranded dna intermediate. the nucleotide sequence of the replication region was determined and an open reading frame of 636 base pairs encoding a protein necessary for plasmid replication was identified by deletion analysis. no significant homology was found between this open reading frame and those en ... | 1993 | 8234484 |
| is231v and w from bacillus thuringiensis subsp. israelensis, two distant members of the is231 family of insertion sequences. | is231 constitutes a family of related insertion sequences (is) from bacillus thuringiensis. two new is231-related elements, is231v and is231w, have been isolated from the 72-mda plasmid of b. thuringiensis subsp. israelensis. these closely related 1964-bp is are delimited by 22-bp imperfect inverted repeats strongly similar to those of the other iso-is231. although the other known is231 harbor a single long open reading frame (orf), is231v and w display two slightly overlapping orf on the same d ... | 1993 | 8234486 |
| complete nucleotide sequence and identification of a putative promoter region for the expression in escherichia coli of the cryia(b) gene from bacillus thuringiensis var. aizawai hd133. | the sequence of a cry gene from bacillus thuringiensis var. aizawai hd133 was determined. this cry gene encodes a protein of 1155 amino acids, the molecular weight of which is 130622 da. when the nucleotide sequence of this cry gene was compared with the nucleotide sequence from b.t. var. aizawai ipl7 and var. berliner 1715, only five nucleotide changes were found. therefore, this cry gene should be grouped into the cryia(b) gene type. a 72 nucleotide sequence upstream of the open reading frame ... | 1993 | 8234543 |
| a study of five bacteriophages of the myoviridae family which replicate on different gram-positive bacteria. | a comparative study is reported on five phages of the myoviridae family which propagate on bacillus subtilis, b. thuringiensis, enterococcus sp., lactobacillus plantarum, or staphylococcus aureus. the phages are morphologically identical and characterized by isometric heads with conspicuous capsomers and by contractile tails with complex base plates. the phages show similar protein profiles, but vary considerably in burst size. phage dnas are about 95-166 kb in size and are unrelated by dna-dna ... | 1993 | 8240019 |
| structural characterization, membrane interaction, and specific assembly within phospholipid membranes of hydrophobic segments from bacillus thuringiensis var. israelensis cytolytic toxin. | the bacillus thuringiensis var. israelensis (bti) cytolytic toxin is hypothesized to exert its toxic activity via pore formation in the cell membrane as a result of the aggregation of several monomers. to gain insight into the toxin's mode of action, 2 putative hydrophobic 22 amino acid peptides were synthesized and characterized spectroscopically and functionally. one peptide corresponded to the putative amphiphilic alpha-helical region (amino acids 110-131, termed helix-2), and the other to am ... | 1993 | 8241124 |
| field trials of bacillus thuringiensis h-14 and bacillus sphaericus (strain 2362) formulations against anopheles arabiensis in the central highlands of madagascar. | malaria is highly endemic and unstable in the central highlands plateau of madagascar. the infection is seasonally transmitted by anopheles funestus and an. arabiensis. the latter species is abundant especially in rice-growing areas. the field efficacies of commercial formulations of bacillus thuringiensis h-14 and b. sphaericus (strain 2362) were assessed against an. arabiensis in 5 types of larval habitats. the granular formulation of b. thuringiensis (vectobac gr) provided very good control i ... | 1993 | 8245944 |
| use of cellular fatty acid analysis to characterize commercial brands of bacillus thuringiensis var. israelensis. | the cellular fatty acid composition of bacillus thuringiensis var. israelensis (b.t.i.) from 5 commercial brands (vectobac, acrobe, skeetal, bactimos and teknar), as well as of the current international standard for b.t.i. (ips 82), was determined using a hewlett-packard microbial identification system. the original strain of b.t.i., b.t. var. kurstaki, b.t. var. thuringiensis, b.t. var. morrisoni and bacillus sphaericus strain 2362 were used as outgroups. acrobe, bactimos, teknar, vectobac and ... | 1993 | 8245945 |
| field trial of two bacillus thuringiensis var. israelensis formulations for control of aedes species mosquitoes in michigan woodlands. | vectobac and bactimos corn cob granules were evaluated for control of aedes species mosquito larvae in woodland pools. no significant differences were seen between the 2 formulations. both provided greater than 90% control at application rates as low as 100 mg/m2 (0.89 lb/acre) and greater than 98% control at label-specified field application rates (2.5 or 5 lb/acre). | 1993 | 8245946 |
| immunological localization of bacillus thuringiensis serovar israelensis toxins in midgut cells of intoxicated anopheles gambiae larvae (diptera: culicidae). | fourth instar larvae of anopheles gambiae were intoxicated with doses of purified crystals from bacillus thuringiensis serovar israelensis (bti) corresponding to 50-fold the lc50 after 24 h. midguts were dissected after various contact times, then processed for immuno-light and -electron microscopy. immunodetection on thin sections was performed using affinity-purified rabbit igg against bti crystal cryivd or cyta polypeptides, in combination with anti-rabbit igg/peroxidase. both polypeptides we ... | 1993 | 8248622 |
| cholesterol oxidase: a potent insecticidal protein active against boll weevil larvae. | the discovery of proteins that control insects is critical for the continued growth of the agricultural biotechnology industry. a highly efficacious protein that killed boll weevil (anthonomus grandis grandis boheman) larvae was discovered in streptomyces culture filtrates. the protein was identified as cholesterol oxidase (e.c. 1.1.3.6). purified cholesterol oxidase was active against boll weevil larvae at a concentration (lc50 = 20.9 micrograms/ml) comparable to the bioactivity of bacillus thu ... | 1993 | 8250897 |
| [complete primary structure of bacillus thuringiensis extracellular ribonuclease]. | complete primary structure of an extracellular low molecular mass ribonuclease of bacillus thuringiensis was determined using edman degradation and mass-spectrometry analysis of individual peptides obtained after hydrolysis of the protein by cyanogen bromide and staphylococcal protease. the peptides were isolated and purified by hplc and denaturing page. the enzyme consists of 109 amino acid residues (asp 8, asn 6, thr 6, ser 10, glu 3, gln 1, pro 3, gly 9, ala 12, val 7, ile 7, leu 7, tyr 7, ph ... | 1993 | 8250978 |
| listeria monocytogenes phosphatidylinositol (pi)-specific phospholipase c has low activity on glycosyl-pi-anchored proteins. | the ability of the phosphatidylinositol-specific phospholipase c (pi-plc) from listeria monocytogenes to hydrolyze glycosyl phosphatidylinositol (gpi)-anchored membrane proteins was compared with the ability of the pi-plc from bacillus thuringiensis to hydrolyze such proteins. the l. monocytogenes enzyme produced no detectable release of acetylcholinesterase from bovine, sheep, and human erythrocytes. the cleavage of the gpi anchors of alkaline phosphatase from rat and rabbit kidney slices was l ... | 1993 | 8253689 |
| formation of melanin pigment by a mutant of bacillus thuringiensis h-14. | a mutant of bacillus thuringiensis h-14 produced a dark brown pigment during sporulation. production of the pigment depended on the nutritional properties of the growth medium. the pigment was identified as melanin, based on chemical tests and its infra-red spectrum. incorporation of l-tyrosine in the culture medium enhanced the level of melanin production, and l-3,4-dihydroxyphenylalanine (l-dopa) was detected in the culture broth during the late-exponential phase of growth. this indicates that ... | 1993 | 8254306 |
| rendering a membrane protein soluble in water: a common packing motif in bacterial protein toxins. | the recently determined structures of three different protein toxins by x-ray crystallography has unexpectedly revealed a common membrane-insertion domain. this domain consists of an alpha-helical bundle of between seven and ten helices, some of which are hydrophobic. the three toxins, colicin, insecticidal delta-endotoxin and diphtheria toxin are directed towards different hosts, have different killing mechanisms and bear no sequence homology. the observation of a common membrane-insertion doma ... | 1993 | 8256289 |
| primary structure of cryx**, the novel delta-endotoxin-related gene from bacillus thuringiensis spp. galleriae. | a cry-related sequence, designated cryx (embl x75019), was localized upstream of cryig, the delta-endotoxin gene cloned from spp. galleriae of bacillus thuringiensis and sequenced earlier [(1991) febs lett. 293, 25-28]. analysis of the cryx complete nucleotide sequence enabled us to explain its virtual crypticity and to reveal the chimeric structure of the genes, cryx and cryig. the amino acid sequence of 1,151 residues encoded by the continuous reading frame of cryx is similar to the other delt ... | 1993 | 8262221 |
| evidence for a glycolipid anchor of gp64, a putative cell-cell adhesion protein of polysphondylium pallidum. | the membrane-bound glycoprotein (gp64) of the cellular slime mold polysphondylium pallidum, is a putative cell-cell adhesion protein identified by adhesion-blocking antibody fragments. since gp64 can be purified in a few days and in substantial yields, it is a good candidate for clarifying the structure of a cell-cell adhesion protein. this study reveals that gp64 possesses a glycolipid anchor which is sensitive to deamination but resistant to phosphatidylinositol-specific phospholipase c from b ... | 1993 | 8269952 |
| hexadecylpalmitoylglycerol or ceramide is linked to similar glycophosphoinositol anchor-like structures in trypanosoma cruzi. | the lipopeptidophosphoglycan from trypanosoma cruzi is a glycosylated inositol-phosphoceramide isolated from epimastigotes at the stationary phase of growth (4-5 days). we have now purified two similar glycoinositolphospholipids (glycoinositolphospholipid a and glycoinositolphospholipid b) from epimastigotes after the second day of culture growth. [3h]palmitic acid was incorporated into 1-o-hexadecyl-2-o-palmitoylglycerol in glycoinositolphospholipid a and into ceramide in glycoinositolphospholi ... | 1993 | 8281945 |
| role of the cryivd polypeptide in the overall toxicity of bacillus thuringiensis subsp. israelensis. | the gene encoding the cryivd protein of b. thuringiensis subsp. israelensis crystals was disrupted by in vivo recombination. the toxicity of the cryivd protein-free inclusions was similar to that of the wild-type crystals on anopheles stephensi larvae but was half the wild-type toxicity on culex pipiens and aedes aegypti larvae. | 1993 | 8285695 |
| characterization of a bacillus thuringiensis strain which is toxic to the housefly musca domestica. | a bacillus thuringiensis isolate has been discovered which is toxic to the common housefly (musca domestica) as well as other diptera and lepidoptera. crystal delta-endotoxins purified from this isolate killed 50% of musca larvae at a concentration of 10.2 micrograms/ml, and beta-exotoxin was not detected. sodium dodecyl polyacrylamide gel electrophoresis of the purified crystals revealed three protein species which were related to cryia(b), cryib and cryiia toxins on the basis of immunoreactivi ... | 1993 | 8293955 |
| identification of a cryptic gene associated with an insertion sequence not previously identified in bacillus thuringiensis. | after screening several bt strains with a cryii toxin probe, clones from two strains were found to contain a cryptic cryiib gene associated with an insertion sequence element belonging to the is2/is3 family. the lack of expression of this gene appears to result from mutation of the upstream orf2 gene which has been shown to be necessary for cryii expression. | 1993 | 8293956 |
| identification of a promoter for the crystal protein-encoding gene cryivb from bacillus thuringiensis subsp. israelensis. | the cryivb gene of bacillus thuringiensis subsp. israelensis (bti) codes for a 135-kda insecticidal crystal protein, which is specifically toxic to dipteran larvae. we have identified a transcription start point (tsp) of cryivb by a primer extension experiment. the promoter sequence alignment, together with the chronology of appearance of the transcript, suggested that cryivb is transcribed by rna polymerase containing sigma 35 (e sigma 35). this was confirmed by investigation of cryivb transcri ... | 1993 | 8299955 |
| is an amphiphilic region responsible for the haemolytic activity of bacillus thuringiensis toxin? | the amino acid sequence of the 27 kda protein responsible for the haemolytic activity of bacillus thuringiensis subsp. israelensis toxin has been analysed by secondary structure prediction, helical wheel/net diagrams and molecular mechanics calculations. we found that segment 116-126 presumably forms a strongly amphiphilic alpha-helix. this is supported by the findings that the synthesized segment 116-126 (a) has a significant alpha-helical content in water, and (b) displays an in vitro haemolyt ... | 1993 | 8307684 |
| an analysis of bacillus thuringiensis delta-endotoxin action on insect-midgut-membrane permeability using a light-scattering assay. | changes in the membrane permeability of manduca sexta midgut brush-border-membrane vesicles (bbmv) after addition of bacillus thuringiensis delta-endotoxins were studied using osmotic swelling experiments, volume changes being monitored as the change in 90 degrees light scattering. typically, control bbmv exhibited limited permeability for sucrose and salts (kcl), while being permeable for urea and glucose. the action of delta-endotoxin was examined using proteolytically activated cry-ia(c) and ... | 1993 | 8319686 |
| x chromosome variations of bacillus thuringiensis supernatant resistance and ribosomal dna content in drosophila melanogaster wild-type oregon r lines. | we have used the supernatant of bacillus thuringiensis cultures to follow variations of the ribosomal dna content in a wild-type oregon r line of drosophila melanogaster. these variations are revealed by differences in the degree of resistance to the lethal effect of the supernatant added in the culture medium. different x chromosomes, all originated from the same x chromosome, confer different degrees of resistance. increases and reductions in the number of the x ribosomal dna transcriptional u ... | 1993 | 8335478 |
| [the efficacy of entomopathogenic bacilli against ancylostomide larvae--nippostrongylus braziliensis travassons, 1914]. | effects of seven bioinsecticides, containing bacillus thuringiensis and b. sphaericus toxins, against n. braziliensis larvae were studied in vitro. bitoxibacillin, astur-3, astur-4, gomelin, lepidocide, dendrobacillin, thuringin and sphaerix were found highly effective larvicides. protein endotoxin was the principal component responsible for the larvicidal effect, the spores were of no importance. | 1993 | 8336643 |
| [the effect of water temperature on the action of bacterial insecticides against mosquito larvae]. | the ld50 logarithm of bacillus thuringiensis and b. sphaericus toxins effects on the larvae of aedes aegypti and culex pipiens is in inverse correlation with the water temperature. the influence of the temperature on the toxins effect on c. pipiens larvae is higher than that for a. aegypti larvae. similarly, b. sphaericus toxin effect depends on the water temperature to a greater measure than that of b. thuringiensis toxin. the authors predict a high efficacy of b. sphaericus-based insecticides ... | 1993 | 8336659 |
| purification and cdna cloning of bovine liver 5'-nucleotidase, a gpi-anchored protein, and its expression in cos cells. | a glycosylphosphatidylinositol (gpi)-anchored protein, 5'-nucleotidase [ec 3.1.3.5], was released from the membrane of bovine liver by use of phosphatidylinositol-specific phospholipase c (pi-plc) of bacillus thuringiensis and purified by several column chromatographies to a homogeneous state. the purified protein has an apparent molecular mass of 61 kda, as estimated by sds-polyacrylamide gel electrophoresis. from the partial amino acid sequence of a tryptic peptide, mixed oligonucleotides were ... | 1993 | 8340354 |
| a 20-kilodalton protein preserves cell viability and promotes cyta crystal formation during sporulation in bacillus thuringiensis. | the effect of a 20-kda protein on cell viability and cyta crystal production in its natural host, bacillus thuringiensis, was studied by expressing the cyta gene in the absence or presence of this protein. in the absence of the 20-kda protein, b. thuringiensis cells either were killed during sporulation (strain cryb) or produced very small cyta crystals (strain 4q7). expression of cyta in the presence of the 20-kda protein, however, preserved cell viability, especially in strain cryb, and in bot ... | 1993 | 8349568 |
| compatibility of cyclopoid copepods with mosquito insecticides. | larvivorous copepods (macrocyclops, mesocyclops and acanthocyclops) were tested for their sensitivities to commonly used mosquito larvicides and adulticides. the cyclopoids were not harmed by bacillus thuringiensis (h-14) (b.t.i.) or larviciding oil. control of mosquito larvae in field trials was accelerated by applying b.t.i. at the same time cyclopoids were introduced to a breeding site. among adulticides tested, the cyclopoids were least sensitive to permethrin. field trials demonstrated that ... | 1993 | 8350070 |
| investigations on possible resistance in aedes vexans field populations after a 10-year application of bacillus thuringiensis israelensis. | in the upper rhine valley (germany), bacillus thuringiensis var. israelensis has been widely used against floodwater mosquitoes over an area of approximately 500 km2 for more than 10 years. the susceptibility of larvae of aedes vexans field populations in 3 untreated (lake constance) and 3 treated areas (upper rhine valley) was assessed by means of bioassays with b.t.i. (bactimos wp, 6,000 aau/mg), following who guidelines. log-probit analyses and statistical evaluations of the data showed that ... | 1993 | 8350079 |
| purification and characterization of a trypsin-like digestive enzyme from spruce budworm (choristoneura fumiferana) responsible for the activation of delta-endotoxin from bacillus thuringiensis. | a trypsin-like enzyme purified from spruce budworm (choristoneura fumiferana) gut juice has a molecular mass of 25 kda and its ph activity profile indicates a pka of 8. sequence homology with bovine trypsin of the n-terminus and active site, and the ionization dependence for catalysis, reflect the typical trypsin-like activities measured. the action of this enzyme (designated cft-1) is compared to the neat gut juice with regard to the proteolytic activation of the delta-endotoxin from bacillus t ... | 1993 | 8353523 |
| insect-resistant chrysanthemum calluses by introduction of a bacillus thuringiensis crystal protein gene. | a 3'-end truncated crystal protein gene, derived from bacillus thuringiensis (bt) subsp. aizawai 7.21, encoding the toxic fragment of the insecticidal protein cryia(b), was constructed. the gene was inserted into a transformation vector, also carrying the neomycin phosphotransferase ii (nptii) gene and the beta-glucuronidase (gus) gene, and introduced in the oncogenic agrobacterium tumefaciens strain a281, harbouring the ti-plasmid ptibo542. the recombinant agrobacterium strain was used to trans ... | 1993 | 8353535 |
| [the role of bacillus thuringiensis in natural biocenoses]. | the results of the author's data and those from literature on ecology and genetic exchange of bacillus thuringiensis strains have been analyzed in this brief review. it has been concluded that there is no strict confinement of b. thuringiensis strains of the particular serotypes to certain habitat and that the bacteriocinogenicity is of great importance in the intraspecies competition and stability of strains in nature. it has been emphasized that the plasmid conjugation process in b. thuringien ... | 1993 | 8355625 |
| use of synthetic peptides to probe functional domains of a bacillus thuringiensis toxin. | two 10-residue peptides exhibiting sequence homology to cryia(a) toxin were chemically synthesized. one corresponds to a segment from residues 48-57 (peptide a) and is common to all cryia toxins and the second corresponds to a segment from residues 348-357 (peptide b) and is specific to the cryia(a) toxin. antibodies were raised in rabbits against both peptides. antipeptide a did not protect either bombyx mori or choristoneura fumiferana larvae against cryia(a) toxin. however, antipeptide b offe ... | 1993 | 8360514 |
| [creation of a hybrid protein gene based on bacillus thuringiensis delta endotoxins cryiiia and cria(a) and expression of its derivatives in escherichia coli]. | the 5'-terminal fragment (containing 1-565th codons) of bacillus thuringiensis var. tenebrionis gene for the coleoptera-specific delta-endotoxin cryiiia was cloned. this sequence was extended with either only a homologous fragment of cryia(a) or that one together with in-frame nptii or gus coding sequences. the obtained gene derivatives were expressed in e. coli. the analysis of hybrid polypeptides confirmed the enzymatic activities of bifunctional proteins and showed toxic properties of "insect ... | 1993 | 8361500 |
| [change in the permeability of liposome phospholipid membranes under the effect of bacillus thuringiensis delta-endotoxins]. | we studied release of the fluorescent calcein marker from egg-lecithin liposomes under action of intact delta-endotoxin from bacillus thuringiensis var. israilensis, and hydrolysed preparation of delta-endotoxin from bacillus thuringiensis var. kurstaki together with the motional parameters of 5- and 12-doxyl stearic radical probes in the liposomal membrane. the yield of the non-penetrating fluorescent marker was shown to be a sensitive indicator of the disturbance of the membrane barrier functi ... | 1993 | 8364069 |
| structural stability of bacillus thuringiensis delta-endotoxin homolog-scanning mutants determined by susceptibility to proteases. | forty homolog-scanning (double-reciprocal-crossover) mutant proteins of two bacillus thuringiensis delta-endotoxin genes (cryiaa and cryiac) were examined for potential structural alterations by a series of proteolytic assays. three groups of mutants could be identified. group 1, consisting of 13 mutants, showed no delta-endotoxin present during overexpression conditions in escherichia coli (48 h at 37 degrees c, with a ptac promoter). these mutants produced full-sized delta-endotoxin detectable ... | 1993 | 8368834 |
| a field survey of bacteriophage contamination of mosquito breeding places, inhibiting bacterial insecticide. | twelve geographically different mosquito breeding places were described and sampled for the detection of naturally existed bacteriophage viruses which could transduct and lysate 5 entomopathogenic bacteria. the surveyed places are classified into seepage, sewage, and irrigation breeding water. bacterial free filtrates of the collected samples were assayed against the tested bacteria in vitro and against 3rd instar culex pipiens larvae as well. nine out of the twelve places could demonstrate the ... | 1993 | 8376856 |
| characterization of tn1546, a tn3-related transposon conferring glycopeptide resistance by synthesis of depsipeptide peptidoglycan precursors in enterococcus faecium bm4147. | sequence determination of the flanking regions of the vancomycin resistance van gene cluster carried by pip816 in enterococcus faecium bm4147 revealed similarity to transposons of the tn3 family. imperfect inverted repeats (36 of 38 bp) delineated a 10,851-bp element designated tn1546. the 4-kb region located upstream from the vanr gene contained two open reading frames (orf) transcribed in opposite directions. the deduced amino acid sequence of orf1 (988 residues) displayed, respectively, 56 an ... | 1993 | 8380148 |