Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| specificity domain localization of bacillus thuringiensis insecticidal toxins is highly dependent on the bioassay system. | the bacillus thuringiensis cryla(a) and cryla(c) gene specificity regions were probed by creating and testing hybrid toxins both in vivo and in vitro against cultured insect cells or dissociated midgut epithelial cells. toxin threshold dose determinations revealed that cryla(c) is highly active against cultured choristoneura fumiferana cells (cf-1) whereas cryla(a) is nontoxic. in live insect bioassays, a reversed order of toxicity was observed. hybrid analysis revealed that the cryla(c) toxicit ... | 1994 | 7715447 |
| comparative toxicity of certain mosquitocidal compounds to larvivorous fish, poecilia reticulata. | toxicity of certain mosquitocidal compounds (both larvicides and adulticides) to the larvivorous fish poecilia reticulata was determined in the laboratory. among the various chemical insecticides tested, the synthetic pyrethroid deltamethrin was most toxic to fish (lc50 = 0.016 ppm), while the organophosphorus insecticide abate was least toxic (lc50 = 34 ppm). the bioinsecticides spherix (bacillus sphaericus) and bactoculicide (bacillus thuringiensis h-14) showed highest safety for the fish (lc5 ... | 1994 | 7713258 |
| bacillus thuringiensis protoxin: location of toxic border and requirement of non-toxic domain for high-level in vivo production of active toxin. | insecticidal crystal proteins, or protoxins, of bacillus thuringiensis are composed of two domains, an amino-terminal half essential for toxicity, and a carboxy-terminal half with an as yet unassigned function. to define the boundary of the two domains, sequential termination codons were introduced from the 3'-end of the dna sequence encoding the toxic domain of the 1155-residue cry1a(b) gene product. the mutated and the intact genes were placed under the control of the escherichia coli inducibl ... | 1995 | 7711901 |
| membrane permeabilization by listeria monocytogenes phosphatidylinositol-specific phospholipase c is independent of phospholipid hydrolysis and cooperative with listeriolysin o. | we have examined potential cooperative interactions of listeria monocytogenes phosphatidylinositol-specific phospholipase c (pi-plc) and listeriolysin o (llo), a pore-forming hemolysin, in a liposome lysis assay. large unilamellar vesicles, approximately 0.1 micron in diameter, encapsulating the fluorescent probe calcein, were treated with pi-plc or llo at ph 6.0, and each was capable of causing dye release. with phosphatidylcholine/phosphatidylinositol/cholesterol liposomes at 0.1 microm lipid, ... | 1995 | 7708759 |
| protocol for the introduction of new bacillus thuringiensis israelensis products into the routine mosquito control program in germany. | the efficacy of new and frequently used formulations of bacillus thuringiensis israelensis (b.t.i.) has been evaluated in the laboratory and in the field conditions under which they will be used in germany. the principles governing the successful introduction of new formulations of microbial control agents into routine programs have been highlighted. the potency of the formulations in use (teknar, bactimos, and vectobac) and their efficacy against the indigenous mosquito species aedes vexans, ae ... | 1994 | 7707059 |
| evaluation of granular corncob formulations of bacillus thuringiensis serovar israelensis against mosquito larvae using a semi-field bioassay method. | a semi-field bioassay method using commonly available laundry tubs evaluated efficacy and residual activity of 6 granular corncob formulations of bacillus thuringiensis serovar israelensis against laboratory-reared late 3rd- and early 4th-instar larvae of aedes taeniorhynchus introduced to the tubs. these formulations produced appreciable larval mortalities (up to 75%) for 9 days posttreatment, with indications of having more prolonged activity. the consistent posttreatment larval mortality tren ... | 1994 | 7707052 |
| production of multiple delta-endotoxins by bacillus thuringiensis: delta-endotoxins produced by strains of the subspecies galleriae and wuhanensis. | a method was developed to assess the number of delta-endotoxins contained in bacillus thuringiensis entomocidal crystals. it utilized proteolytic conversion of 130-kda protoxin into 60- to 65-kda "true" toxin via limited proteolysis with trypsin and separation of stable n-terminal domains by fast-performance liquid chromatography. immunodiffusion experiments and n-terminal sequence determination (applied to the major component isolated by sds-page) completed the analysis of the crystal protein c ... | 1994 | 7704829 |
| ion channel activity of n-terminal fragments from cryia(c) delta-endotoxin. | proteolytically-derived amino-terminal fragments from the bacillus thuringiensis delta-endotoxin, cryia(c), demonstrated ion channel activity in two in vitro assays in the absence of any membrane receptors. a 24.5 kda fragment (from spodoptera frugiperda digestive proteolysis) formed cation-selective channels (10mv for a 3:1 salt gradient) in planar lipid bilayers up to several hundred picosiemen conductance. a 21.5 kda fragment doublet (from alkaline hydrolysis) also showed large conductance in ... | 1993 | 7694582 |
| characterization of an avirulent pleiotropic mutant of the insect pathogen bacillus thuringiensis: reduced expression of flagellin and phospholipases. | an avirulent pleiotropic mutant of the insect pathogen bacillus thuringiensis subsp. gelechiae, isolated by heierson et al. (a. heierson, i. sidén, a. kivaisi, and h. g. boman, j. bacteriol. 167:18-24, 1986) as a spontaneous phage-resistant mutant, was further characterized and found to lack the expression of phosphatidylcholine- and phosphatidylinositol-degrading phospholipase c, beta-lactamase, and flagellin because of the absence of corresponding mrnas. the avirulent mutant was also found to ... | 1993 | 7693592 |
| effect of promoter modification on mosquitocidal cryivb gene expression in synechococcus sp. strain pcc 7942. | the impact of promoter modification on the expression of the mosquitocidal bacillus thuringiensis subsp. israelensis cryivb gene when used to transform the cyanobacterium synechococcus sp. strain pcc 7942 has been examined. maximal transcript and protein abundances were achieved by the addition of the lacz promoter upstream of the cryivb sequence. replacement of the endogenous corresponding bacillus sequences with the synechococcus petf1 promoter, ribosome binding site, and initiation codon also ... | 1993 | 7690220 |
| lepidopteran-specific crystal toxins from bacillus thuringiensis form cation- and anion-selective channels in planar lipid bilayers. | previous studies in our laboratory have shown that cryic, a lepidopteran-specific toxin from bacillus thuringiensis, triggers calcium and chloride channel activity in sf-9 cells (spodoptera frugiperda, fall armyworm). chloride currents were also observed in sf-9 membrane patches upon addition of cryic toxin to the cytoplasmic side of the membrane. in the present study the ability of activated cryic toxin to form channels was investigated in a receptor-free, artificial phospholipid membrane syste ... | 1993 | 7681482 |
| expression and synergistic effect of three types of crystal protein genes in bacillus thuringiensis. | bacillus thuringiensis nt0423 newly isolated from sericultural farms in korea produces quite atypical bipyramidal crystals of a common major band of ca. 130 kda, and has dual specificity against lepidoptera and diptera. to enforce the diptera toxicity of b. thuringiensis nt0423, cryivd and cyta genes were transformed into b. thuringiensis nt0423. the transformant b. thuringiensis pt0529 was obtained from introduction of pcg5 into b. thuringiensis nt0423 by electroporation. the expression of crys ... | 1995 | 7677771 |
| deletion mutants of the gene encoding delta-endotoxin specific to scarabaeid beetles: minimum region of the gene required to express the activity. | various deletion genes for the delta-endotoxin protein of bacillus thuringiensis strain buibui were made. the truncated proteins were produced in e. coli, and their larvicidal activity against the cupreous chafer was checked. the fifth block of the five blocks described as "conserved" was shown to be necessary for the activity. | 1995 | 7670204 |
| domain organization of bacillus thuringiensis cryiiia delta-endotoxin studied by denaturation in guanidine hydrochloride solutions and limited proteolysis. | denaturation of bacillus thuringiensis cryiiia delta-endotoxin--an insecticidal protein, active against coleoptera larvae--in concentrated guanidine hydrochloride solutions was pursued by fluorescence and circular dichroism spectroscopy and limited proteolysis. it was found that the protein consists of two fragments that differ by their stability to denaturation by guanidine hydrochloride at ph 3. the less stable fragment corresponds to the n-terminal alpha-helical domain limited by leu-279; the ... | 1995 | 7662112 |
| a glycoprotein multimer from bacillus thuringiensis sporangia: dissociation into subunits and sugar composition. | two glycoproteins (205 and 72 kda) were found in bacillus thuringiensis sporangia. they were predominantly localized in the exosporium and/or the spore coat, although a small proportion was also found in membranes. a method for the dissociation of hydrophobic aggregates that resist the usual conditions of sds-page is described. using this method we established that the 205 kda glycoprotein is a multimer of the 72 kda one. deglycosylation of the 205 kda and 72 kda glycoproteins with trifluorometh ... | 1995 | 7659076 |
| safety testing of bacillus thuringiensis preparations, including thuringiensin, using the salmonella assay. | the aim of this study was to test genotoxicity aspects of the safety of two strains of bacillus thuringiensis. the strains were of serotype h-1, producing thuringiensin, toxic to flies, and serotype h-14, producing endotoxin, toxic to mosquitoes, but not thuringiensin. four preparations were tested: tenfold concentrated cell-free culture media of serotypes h-1 and h-14, prepurified thuringiensin, and purified endotoxin. no increases in revertant colony numbers of the tester strains of salmonella ... | 1995 | 7658050 |
| 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 ... | 1995 | 7658049 |
| 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 ... | 1995 | 7657602 |
| 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 ... | 1995 | 7646454 |
| 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 ... | 1995 | 7639990 |
| 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 ... | 1995 | 7632920 |
| 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 ... | 1995 | 7629076 |
| 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 ... | 1995 | 7626052 |
| 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 ... | 1995 | 7618886 |
| 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 ... | 1995 | 7618866 |
| 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 ... | 1995 | 7616196 |
| 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 ... | 1995 | 7616194 |
| 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 ... | 1995 | 7616175 |
| 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 ... | 1995 | 7608080 |
| 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 ... | 1995 | 7608077 |
| 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 ... | 1995 | 7595459 |
| 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 ... | 1995 | 7595442 |
| 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 ... | 1995 | 7592988 |
| how does bacillus thuringiensis produce so much insecticidal crystal protein? | 1995 | 7592363 | |
| [change in the bacillus thuringiensis subsp. israelensis plasmid dna spectrum during growth dynamics]. | 1995 | 7580992 | |
| 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 ... | 1995 | 7576527 |
| 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 ... | 1995 | 7568463 |
| 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 ... | 1995 | 7559587 |
| 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 ... | 1995 | 7549769 |
| 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 ... | 1995 | 7548766 |
| 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 ... | 1995 | 7547144 |
| 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 ... | 1995 | 7538281 |
| 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 ... | 1995 | 7533728 |
| 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 ... | 1995 | 7531814 |
| 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 ... | 1994 | 7529493 |
| 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 ... | 1994 | 7527203 |
| 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. | 1994 | 7521154 |
| 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 ... | 1994 | 7516963 |
| 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 ... | 1994 | 7514590 |
| 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 ... | 1993 | 7504667 |
| the safety of bacillus species as insect vector control agents. | 1994 | 7499181 | |
| 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 ... | 1995 | 7494502 |
| 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 ... | 1995 | 7490762 |
| 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 ... | 1995 | 7488105 |
| 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 ... | 1995 | 7487039 |
| 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 ... | 1995 | 7487029 |
| 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 ... | 1995 | 7486995 |
| [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 ... | 1995 | 7483588 |
| 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 ... | 1995 | 7478260 |
| effects of the spore-endotoxin complex of a strain of bacillus thuringiensis serovar morrisoni upon triatoma vitticeps (hemiptera: reduviidae) under laboratory conditions. | 1994 | 7476224 | |
| 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 ... | 1981 | 7462165 |
| 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 ... | 1981 | 7462158 |
| 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 ... | 1980 | 7459713 |
| role of glutamic acid & glutamate dehydrogenase in sporulation of bacillus thuringiensis var. thuringiensis in chemically defined media. | 1980 | 7450794 | |
| 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 ... | 1980 | 7420053 |
| 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 ... | 1980 | 7417468 |
| bacillus thuringiensis parasporal crystal toxin: dissociation into toxic low molecular weight peptides. | 1980 | 7417316 | |
| 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 ... | 1980 | 7414596 |
| [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 ... | 1980 | 7405137 |
| patterns of plasmid dna in crystalliferous and acrystalliferous strains of bacillus thuringiensis. | 1980 | 7335824 | |
| isolation of a protein from the parasporal crystal of bacillus thuringiensis var. kurstaki toxic to the mosquito larva, aedes taeniorhynchus. | 1981 | 7332548 | |
| [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 ... | 1981 | 7324378 |
| 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. | 1981 | 7320315 | |
| [toxicity of bacillus thuringiensis var. israelensis serotype hi4, for larvae of sandflies, the leishmaniasis vectors (author's transl)]. | 1981 | 7318051 | |
| [detection of thermolabile exotoxin in b. thuringiensis and its separation from phospholipase c]. | 1981 | 7315023 | |
| [activity of the serotype h-14 of bacillus thuringiensis against the principal species of anthropophilic mosquitoes of the french mediterranean coast]. | 1980 | 7312403 | |
| [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 ... | 1980 | 7312402 |
| [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]. | 1980 | 7312401 | |
| [sensitization and hyposensitization to bac. thuringiensis]. | 1981 | 7308791 | |
| [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 ... | 1981 | 7306883 |
| 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 ... | 1981 | 7306875 |
| [innocuousness of bacillus thuringiensis var. israelensis for the larvae of oysters]. | 1981 | 7296737 | |
| [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. | 1981 | 7296735 |
| correlation between specific plasmids and delta-endotoxin production in bacillus thuringiensis. | 1981 | 7267811 | |
| 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 ... | 1980 | 7252480 |
| [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 ... | 1981 | 7249246 |
| occurrence of resistance to neomycin and kanamycin in bacillus popilliae and certain serotypes of bacillus thuringiensis: mutation potential in sensitive strains. | 1981 | 7240780 | |
| 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. | 1981 | 7217007 |
| [growth characteristics of polylysogenic culture of bacillus thuringiensis subspecies galleriae in a chemostat]. | 1980 | 7207265 | |
| [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. | 1980 | 7207263 |
| 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 ... | 1981 | 7204384 |
| [hygienic basis of processes utilizing plant products grown using bac. thuringiensis-based bacterial insecticides]. | 1980 | 7203061 | |
| [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 ... | 1981 | 7198072 |
| [initiators and inhibitors of spore germination of bacillus thuringiensis]. | 1982 | 7176973 | |
| [study of sporulation of the bacterium bac. thuringiensis apropos of its infection by phages, using the method of mathematical planning of experiments]. | 1982 | 7168255 | |
| activity of a "thermostable exotoxin" of bacillus thuringiensis subsp. morrisoni in the salmonella/microsomal assay for bacterial mutagenicity. | 1982 | 7153535 | |
| laboratory evaluation of bacillus thuringiensis var. israelensis serotype h-14 against mosquito larvae with particular reference to aedes aegypti. | 1982 | 7153478 | |
| [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. | 1982 | 7144612 |
| 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 ... | 1982 | 7139413 |
| [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 ... | 1982 | 7138972 |