Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| characterization of the cysteine residues and disulphide linkages in the protein crystal of bacillus thuringiensis. | bacillus thuringiensis produces a 130-140 kda insecticidal protein in the form of a bipyramidal crystal. the protein in the crystals from the subspecies kurstaki hd-1 and entomocidus was found to contain 16-18 cysteine residues per molecule, present primarily in the disulphide form as cystine. evidence that all the cysteine residues form symmetrical interchain disulphide linkages in the protein crystal was obtained from the following results: (i) the disulphide diagonal procedure [brown & hartle ... | 1990 | 2110449 |
| response of nuclear polyhedrosis virus-resistant spodoptera frugiperda larvae to other pathogens and to chemical insecticides. | selection in the laboratory for spodoptera frugiperda (sf) resistant to nuclear polyhedrosis virus (npv) affected the susceptibility of the insect to certain other mortality agents, including a chemical insecticide. median lethal concentrations (lc50s) and associated statistics were compared for several mortality agents between colonies of npv-resistant and -susceptible (control) insects. compared to the susceptible insects, the npv-resistant insects were cross-resistant to the s. frugiperda gra ... | 1990 | 2108223 |
| isolation and propagation of phages naturally associated with the aizawai variety of bacillus thuringiensis. | this study describes the isolation of a phage, using mitomycin c and u.v. light, from each of four strains (hd67, hd130, hd228 and hd248) of bacillus thuringiensis h-serotype 7 (var. aizawai). it also describes the isolation of two indicator strains (12.13 and hd102) for these phages (phi hd67, phi hd130, phi hd228 and phi hd248) and the ideal conditions, using these indicator strains, for maximum phage production. | 1990 | 2107162 |
| effect of phospholipase c from bacillus cereus on the release of membrane-bound choline-o-acetyltransferase from rat hippocampal tissue. | some of the enzyme choline-o-acetyltransferase (chat) associated with central cholinergic nerve terminals appears to be non-ionically associated with membranes. in the present study, we tested the possibility that some membrane-bound chat might be anchored to membranes by a phosphatidylinositol linkage by incubating rat hippocampal tissue with phospholipase c (plc) from bacillus cereus. the plc selectively augmented the release of chat; also, the glycosylphosphatidylinositol-plc inhibitor, zinc, ... | 1990 | 2106007 |
| chemical management of forest pest epidemics: a case study. | the management of insect epidemics in large tracts of forest is difficult given the climatic conditions encountered, the topography of the forested land, the nature of the forest, the types of chemical and/or biological insecticides registered for use, and the technologies available for insecticide application. since 1952, the province of new brunswick, canada, has been heavily involved in attempting to control an epidemic of the eastern spruce budworm (choristoneura fumiferana. clemens) that ha ... | 1990 | 2099793 |
| integrated use of planaria (dugesia dorotocephala) and bacillus thuringiensis var. israelensis against aedes taeniorhynchus: a laboratory bioassay. | the effectiveness of integrating bacillus thuringiensis var. israelensis (b.t.i.) and the predatory planaria, dugesia dorotocephala against aedes taeniorhynchus was determined under controlled laboratory conditions. there was no significant effect (p greater than 0.05) of b.t.i. on d. dorotocephala either by direct association or through ingestion of b.t.i. dosed larvae. planaria, alone, and b.t.i. combined with planaria, both provided significant (p less than 0.05) reduction of ae. taeniorhynch ... | 1990 | 2098475 |
| [the choice of the optimal aeration conditions for the stab cultivation of bacillus thuringiensis h14 266/2-1]. | optimal conditions of aeration with depth regime of cultivation of bacillus thuringiensis h14 266/2-1, their effect on the output of biomass, endotoxin and activity of bacteria have been studied. the aeration conditions are optimized using the mathematical method of experiment planning. it is established that the air supply favours an increase of the bacillary biomass and insecticide activity for the whole cultivation period. in the first day of fermentation it is inexpedient to increase to rate ... | 1990 | 2097498 |
| molecular characterization of immune inhibitor a, a secreted virulence protease from bacillus thuringiensis. | the gene for the secreted neutral metalloprotease, immune inhibitor a (ina), from bacillus thuringiensis var. alesti has been cloned and sequenced. the deduced amino acid sequence has been confirmed by partial amino acid sequencing. the central part of the amino acid sequence showed similarity to the active site in thermolysin. southern and western blots show that ina-related sequences are common among other b. thuringiensis subspecies. in western blots, 17 out of 25 tested species gave a positi ... | 1990 | 2089225 |
| activation of a cryptic crystal protein gene of bacillus thuringiensis subspecies kurstaki by gene fusion and determination of the crystal protein insecticidal specificity. | dna hybridization with the insecticidal crystal protein gene crylla (formerly crybl) of bacillus thuringiensis supspecies kurstaki has shown that subspecies kurstaki contains a crylla-related sequence in addition to the crylla gene (donovan et al., 1988a). we have cloned the crylla-related sequence and have determined that the sequence, which has been designated cryllb, is 89% identical to the crylla gene. recombinant b. thuringiensis cells harbouring the cloned cryllb gene produced very little ... | 1990 | 2089222 |
| larvicidal activity of chimeric bacillus thuringiensis protoxins. | bacillus thuringiensis subspecies kurstaki (btk) and subspecies berliner (btb) both produce lepidopteran-specific larvicidal protoxins with different activities against the same insect species. toxic activity resides in the amino-terminal half of both protoxins, whereas the carboxy-terminal half of the molecules is not required for toxicity. the protoxins are 90% homologous, with a major cluster of differences in the amino-terminal half, and a 26 consecutive amino-acid insertion within the carbo ... | 1990 | 2082153 |
| [the effect of exposure and feed on the results of the testing of bacterial insecticides on mosquito larvae]. | it has been established that the duration of exposition and the availability of larval feed have a reliable effect on the index of insecticide activity (lc-50) of bacterial preparations as regards mosquito larvae. high degree of correlation between the results obtained in different conditions makes it possible to calculate the lc-50 values for any combination of exposition and feed availability, if an index for one of the combinations is known (the formula is presented). the proposed variant of ... | 1991 | 2067465 |
| photoprotection of bacillus thuringiensis kurstaki from ultraviolet irradiation. | irradiation of bacillus thuringiensis var. kurstaki hd1 at 300-350 nm for up to 12 hr using a photochemical reactor results in a rapid loss of its toxicity to larvae of heliothis armigera. photoprotection of the toxic component was obtained by adsorption of cationic chromophores such as acriflavin (af), methyl green, and rhodamine b to b. thuringiensis. af gave the best photoprotection and a level of 0.42 mmol/g dye absorbed per gram of b. thuringiensis was highly toxic even after 12 hr of ultra ... | 1991 | 2066575 |
| isolation and characterization of a novel insecticidal crystal protein gene from bacillus thuringiensis subsp. aizawai. | bacillus thuringiensis subsp. aizawai eg6346, a novel grain dust isolate, was analyzed by southern blot hybridization for its insecticidal crystal protein (icp) gene profile. strain eg6346 lacks previously characterized cryia icp genes yet does possess novel cryi-related gene sequences. a recombinant genomic plasmid library was constructed for strain eg6346 in escherichia coli. one recombinant plasmid, peg640, isolated from the library contained a novel icp gene on a 5.7-kb sau3a insert. the seq ... | 1991 | 2061280 |
| the solubility of inclusion proteins from bacillus thuringiensis is dependent upon protoxin composition and is a factor in toxicity to insects. | bacillus thuringiensis subsp. aizawai hd133 is one of several strains particularly effective against plodia interpunctella selected for resistance to b. thuringiensis subsp. kurstaki hd1 (dipel). b. thuringiensis subsp. aizawai hd133 produces inclusions containing three protoxins, cryia(b), cryic, and cryid, and the cryic protoxin has been shown to be active on resistant p. interpunctella as well as on spodoptera larvae. the cryia(b) protoxin is very similar to the major one in b. thuringiensis ... | 1991 | 2059054 |
| characterization of mosquitocidal activity of bacillus thuringiensis subsp. fukuokaensis crystal proteins. | the mosquitocidal crystals of bacillus thuringiensis subsp. fukuokaensis were isolated and bioassayed against fourth-instar larvae of two mosquito species. the 50% lethal concentration values of the crystals to aedes aegypti and culex quinquefasciatus were 4.1 and 2.9 micrograms/ml, respectively. in addition, the solubilized crystals had hemolytic activity; 50 micrograms/ml was the lowest detectable level. sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that the cryst ... | 1991 | 2059032 |
| transduction of certain genes by an autonomously replicating bacillus thuringiensis phage. | a derivative of bacillus thuringiensis subsp. kurstaki hd1 (hd1-9) released transducing phage (tp21) from late exponential cultures. three of seven markers tested were transduced into bacillus cereus, but only two of these (cysc and trpb/f) were transduced at a frequency of more than 100 times the reversion rates. a limited transduction capacity was given further support in that few chromosomal markers were carried in the hd1-9 lysate, as demonstrated by southern hybridization. restriction fragm ... | 1991 | 2059027 |
| spiroplasma (mollicutes: spiroplasmataceae) pathogenic for aedes aegypti and anopheles stephensi (diptera: culicidae). | intrathoracic inoculation with the mosquito spiroplasma, spiroplasma taïwanense abalain-colloc et al., was found to reduce significantly the survival of adult male and female aedes aegypti (l.) and anopheles stephensi liston. this spiroplasma also reduced significantly the flight capacity of adult female ae. aegypti 5-8 d after inoculation and adult female an. stephensi 4 d after inoculation. adult female an. stephensi were incapable of flight 5 d after inoculation. as such, s. taïwanense joins ... | 1991 | 2056503 |
| resistance to the bacillus thuringiensis bioinsecticide in a field population of plutella xylostella is due to a change in a midgut membrane receptor. | the biochemical mechanism for resistance to bacillus thuringiensis crystal proteins was studied in a field population of diamondback moths (plutella xylostella) with a reduced susceptibility to the bioinsecticidal spray. the toxicity and binding characteristics of three crystal proteins [cryia(b), cryib, and cryic] were compared between the field population and a laboratory strain. the field population proved resistant (greater than 200-fold compared with the laboratory strain) to cryia(b), one ... | 1991 | 2052591 |
| microbial larvicides for the control of nuisance aquatic midges (diptera: chironomidae) inhabiting mesocosms and man-made lakes in california. | bacillus thuringiensis var. israelensis (b.t.i.) and b. sphaericus were evaluated for chironomid larvicidal activity in freshwater mesocosms. of two b.t.i. formulations, the technical powder abg-6164 provided excellent control of chironomines (94%) at the rate of 11.2 kg/ha whereas the liquid concentrate, vectobac 6 as, achieved only moderate control (57%) at the rate of 22.4 kg/ha. in contrast, similar rates of b. sphaericus products, abg-6184 technical powder and bsp-2 flowable concentrate, pr ... | 1991 | 2045809 |
| identification of a gene (mob14-3) encoding a mobilization protein from the bacillus thuringiensis subsp. israelensis plasmid ptx14-3. | 1991 | 2041752 | |
| insecticidal toxins from bacillus thuringiensis subsp. kenyae: gene cloning and characterization and comparison with b. thuringiensis subsp. kurstaki cryia(c) toxins. | genes encoding insecticidal crystal proteins were cloned from three strains of bacillus thuringiensis subsp. kenyae and two strains of b. thuringiensis subsp. kurstaki. characterization of the b. thuringiensis subsp. kenyae toxin genes showed that they are most closely related to cryia(c) from b. thuringiensis subsp. kurstaki. the cloned genes were introduced into bacillus host strains, and the spectra of insecticidal activities of each cry protein were determined for six pest lepidopteran insec ... | 1991 | 2014985 |
| modification of the coding sequence enhances plant expression of insect control protein genes. | increased expression of the insect control protein genes of bacillus thuringiensis in plants has been critical to the development of genetically improved plants with agronomically acceptable levels of insect resistance. the expression of the cryia(b) gene was compared to partially modified (3% nucleotide difference) and to fully modified (21% nucleotide difference) cryia(b) and cryia(c) genes in tobacco and tomato. the modified genes increased the frequency of plants that produced the proteins a ... | 1991 | 2014252 |
| in vivo generation of hybrids between two bacillus thuringiensis insect-toxin-encoding genes. | the parasporal crystal of bacillus thuringiensis is composed of polypeptides highly toxic to a number of insect larvae. the structural genes (cryia) encoding the lepidoptera-specific toxin from different bacterial strains diverge primarily in a single hypervariable region, whereas the n-terminal and c-terminal parts of the proteins are highly conserved. in this report, we describe the generation of hybrid genes between two cryia genes. two truncated cryia genes were cloned in a plasmid vector in ... | 1991 | 2013409 |
| research on biological pest control moves ahead. | 1991 | 2011760 | |
| peptide mapping of different bacillus thuringiensis toxin gene products by cnbr cleavage in sds-page gels. | a cyanogen bromide fragmentation reaction of 3 hr in sodium dodecyl sulfate gel slices was used for the degradation of the toxins coded by the three cryia genes from bacillus thuringiensis kurstaki. peptide patterns diagnostic for each toxin gene product were observed. treatment longer than 3 hr led to the weakening and disappearance of protein bands. in 9 out of 16 wild b. thuringiensis strains tested, it was determined that only one of the cryia genes was being expressed; in 6 strains, one to ... | 1991 | 2002246 |
| chemical modification of bacillus thuringiensis subsp. thuringiensis (hd-524) trypsin-activated endotoxin: implication of tyrosine residues in lepidopteran cell lysis. | a purified protein fraction from a solubilized and trypsin-digested extract of bacillus thuringiensis subsp. thuringiensis (hd-524) fermentation powder was lytic to cells from several lepidopteran lines. maximum yield was obtained by alkaline carbonate-thiocyanate solubilization of washed powder followed by trypsin digestion and sephacryl (s-300) chromatography. the alkaline carbonate-solubilized fraction consisted predominantly of two bands on sodium dodecyl sulfate-polyacrylamide gel electroph ... | 1991 | 2002242 |
| efficient transformation of bacillus thuringiensis requires nonmethylated plasmid dna. | the transformation efficiency of bacillus thuringiensis depends upon the source of plasmid dna. dna isolated from b. thuringiensis, bacillus megaterium, or a dam- dcm- escherichia coli strain efficiently transformed several b. thuringiensis strains, b. thuringiensis strains were grouped according to which b. thuringiensis backgrounds were suitable sources of dna for transformation of other b. thuringiensis strains, suggesting that b. thuringiensis strains differ in dna modification and restricti ... | 1991 | 1991728 |
| the effect of bacillus thuringiensis israelensis [h-14] on emergence of mansonia mosquitos from natural breeding habitat. | the measurement of the ultimate effects of the microbial insecticides on mosquito density is best obtained by assessment of adult populations. the main aims of this study are: (1) to assess the effect of bacillus thuringiensis israelensis (bti) fc skeetal and bactimos briquettes on the emergence rate of mansonia bonneae developed from the introduced first-instar stage larvae and (2) to measure the effect of these two formulations of insecticides on mansonia adult populations emerging from the na ... | 1990 | 1981631 |
| effects of bacillus thuringiensis delta-endotoxin on the permeability of brush border membrane vesicles from tobacco hornworm (manduca sexta) midgut. | 1. the effect of two recombinant bacillus thuringiensis delta-endotoxins on brush border membrane vesicles of manduca sexta midgut was investigated using an in vitro assay system, based on ion-amino acid cotransport. 2. a cryia(b)-toxin provoked an increase in the permeability of the vesicles. 3. a cryib-toxin, not toxic to m. sexta larvae in vivo, had no effect in our assay. 4. in contrast to earlier reports, the increase in permeability was found to be neither selective for k+ nor specifically ... | 1990 | 1977553 |
| efficacy and persistence of bacillus sphaericus, bacillus thuringiensis var. israelensis, and methoprene against culiseta incidens (diptera: culicidae) in tires. | the efficacy and persistence of bacillus sphaericus (2362) was compared at three dosage rates in tires that continually contained cadavers of culiseta incidens (thomson) versus tires with all dead larvae removed. at treatment rates of 3.75 and 7.5 ppm, the continual presence of cadavers in the tire water resulted in higher mortality rates. at the 15 ppm treatment rate, mortality rates were similar in tires with or without cadavers. mortality rates increased in all tires 4-6 wk after treatment, s ... | 1990 | 1976658 |
| function of the hydrophobic transmembrane portion of thy-1 antigen. | thy-1 antigen is anchored in the cell membrane by glycophosphatidyl inositol linkages instead of hydrophobic protein domains. the hydrophobic portion of thy-1 antigen is cleaved by putative "transamidase." mutated genes were constructed by using site-directed mutagenesis. one mutant gene codes thy-1 antigen lacking carboxy terminal amino acids from 112cys to 143leu including cell membrane binding amino acid 112cys. the other mutant gene codes thy-1 antigen lacking from 124trp to 143leu that incl ... | 1990 | 1975422 |
| the medical importance of riceland mosquitoes and their control using alternatives to chemical insecticides. | the medical importance, ecology and control of riceland mosquitoes using alternative strategies is reviewed. over 135 pest and vector anopheline and culicine mosquito species found in association with riceland habitats and their medical importance are presented. malaria and japanese encephalitis are the two most serious human diseases transmitted by riceland mosquitoes, but they have been incriminated as vectors of dozens of arboviruses and other parasites and pathogens including the causal agen ... | 1990 | 1973949 |
| relative potency of bacillus thuringiensis var. israelensis and bacillus sphaericus 2362 for mansonia titillans and mansonia dyari. | bacillus thuringiensis var. israelensis (b.t.i.), hd-968-s-1983, and a primary powder of bacillus sphaericus 2362 were assayed against mansonia titillans and ma. dyari. the susceptibility of the 2 species to the individual bacterial toxins was similar. the b.t.i. lc50 values were 50.5 micrograms/liter for ma. dyari and 54.7 micrograms/liter for ma. titillans; the b. sphaericus lc50 values were 339.0 micrograms/liter and 347.2 micrograms/liter, respectively. the log dose-probit mortality lines we ... | 1990 | 1973452 |
| evaluation of bactimos wettable powder, granules and briquets against mosquito larvae in malaysia. | there was high mortality in late larval instars of aedes albopictus (skuse) from laboratory and field populations in the 24 h after application of three bactimos formulations of bacillus thuringiensis h-14. mortalities were higher and residual effects longer in field populations than in laboratory ones. briquets were the most effective formulation (mortality 96-100% after five weeks; 76-92% after eight weeks). culex quinquefasciatus say larvae were tested only against the briquet formulation. in ... | 1990 | 1973019 |
| [clostridium bifermentans serovar malaysia, a new anaerobic bacterium pathogen to mosquito and blackfly larvae]. | a strain of clostridium bifermentans individualized as serovar malaysia (c.b.m.) according to its specific h antigen is toxic to mosquito and blackfly larvae when given orally. the toxicity occurs in sporulated cells which contain, in addition to spores, proteinic parasporal inclusion bodies and feather-like appendages; the amino acid content of the inclusion bodies is similar to that of bacillus thuringiensis serovar israelensis (b.t.i.) and b. sphaericus crystals. the toxicity to anopheles ste ... | 1990 | 1972899 |
| efficacy of various bacillus thuringiensis var. israelensis formulations against psorophora columbiae larvae as assessed in small rice plots, 1984-88. | granular, liquid and briquette formulations of bacillus thuringiensis var. israelensis were tested in small rice plots during 1984-88 against psorophora columbiae larvae. vectobac as, skeetal g, teknar hpd, abg 6172, abg 6188, abg 6193, abg 6197, abg 6199, abg 6138f and abg 6221 provided excellent control at high dosages and good control (generally greater than 85%) at relatively low concentrations. abg 6221 and abg 6172 provided excellent control at low concentrations. additional testing of the ... | 1990 | 1969931 |
| development of mutants of the mosquitocidal bacterium bacillus thuringiensis subspecies morrisoni (pg-14) toxic to lepidopterous or dipterous insects. | the parasporal body of the mosquitocidal isolate (pg-14) of bacillus thuringiensis subsp. morrisoni (btm) contains five major proteins with molecular masses of, respectively, 27.3, 65, 128, 135, and 144 kda. proteins corresponding in mass to the first four of these also occur in the mosquitocidal strain, b. thuringiensis subsp. israelensis (bti), and it is thought therefore that the mosquitocidal activity of both strains is due to these four proteins. in other studies it has been shown that each ... | 1990 | 1969828 |
| comparison of development of bacillus thuringiensis subsp. israelensis and bacillus sphaericus in mosquito larvae. | immunofluorescent staining was used with thin sections of paraffin-embedded specimens to detect the development of bacillus thuringiensis var. israelensis and bacillus sphaericus in the gut of mosquito larvae. the third- and fourth-instar larvae of aedes aegypti, anopheles maculatus, and culex quinquefasciatus were fed either vegetative cells or spores of the bacteria. spore germination, multiplication, and sporulation were studied in the larvae of each species. the spores of b. thuringiensis va ... | 1990 | 1969455 |
| characterization of the parasporal inclusion of bacillus thuringiensis subsp. kyushuensis. | electron microscopy of bacillus thuringiensis subsp. kyushuensis revealed that the parasporal inclusions are composed of a homogeneous center surrounded by a thick, electron-dense coating. antibodies directed against the 135- and 65-kilodalton b. thuringiensis subsp. israelensis peptides cross-reacted with the 70- and 26-kilodalton peptides, respectively, of b. thuringiensis subsp. kyushuensis. | 1990 | 1967173 |
| purification of the temperature-specific surface antigen of paramecium primaurelia with its glycosyl-phosphatidylinositol membrane anchor. | the membrane form of the temperature-specific g surface antigen of paramecium primaurelia strain 156 has been purified by a novel procedure utilizing solubilization by detergent, ammonium sulfate precipitation, and high-performance liquid chromatography. the surface antigen, which was prepared in a nondenatured state containing a glycosyl-phosphatidylinositol membrane anchor, migrated as a single band upon electrophoresis in sodium dodecyl sulfate-polyacrylamide gels. following cleavage of the p ... | 1990 | 1967078 |
| models for the structure and function of the bacillus thuringiensis delta-endotoxins determined by compilational analysis. | the protein delta-endotoxins of bacillus thuringiensis are a commercially and environmentally important class of highly specific insecticides. from an alignment of their sequences, certain structural and functional domains can be inferred which may shed light on the mode of action of these toxins. | 1990 | 1966871 |
| phosphatidylinositol-attached 5'-nucleotidase from synaptic plasma membrane of rat brain. | synaptic plasma membranes (spm) of rat brain contained a 5'-nucleotidase that was specifically released by bacillus thuringiensis phosphatidylinositol-specific phospholipase c (piplc). about 30% of the enzyme was readily released and the remainder was less susceptible. purified 5'-nucleotidase was treated with piplc and the resultant enzyme was almost totally partitioned into the detergent-poor phase following phase-separation in triton x-114 indicating that piplc converted the enzyme from an am ... | 1990 | 1965942 |
| formulation of a flowable liquid concentrate of bacillus thuringiensis serotype h-14 spores and crystals as mosquito larvicide. | bacillus thuringiensis serotype h-14 spores and crystals, produced in 51 fermenters, were centrifuged and resuspended in emulsified palm olein to give 3.2 x 10(11) colony forming units (cfu)/ml. the suspension was mixed with a cassava-molasses-palm olein-charcoal (cmpc-2) mixture which served as the carrier, adhesive, dispersant and protectant. the final concentration of the formulation was 3.2 x 10(9) cfu/ml. the lethal concentrations capable of killing 50% of the test population (lc50) of cmpc ... | 1991 | 1955414 |
| bacillus thuringiensis and pest control. | 1991 | 1953905 | |
| fermentation of a malaysian bacillus thuringiensis serotype h-14 isolate, a mosquito microbial control agent utilizing local wastes. | a screening program searching for indigenous microbial control agents of mosquitos in malaysia is initiated since 1987 and to date at least 20 isolates of mosquitocidal bacillus thuringiensis serotypes have been obtained. preliminary field evaluation of several isolates indicated that they are highly effective in the control of medically important mosquito species. for operational purposes, there is an urgent need to produce this agent utilizing cheap and locally available wastes through ferment ... | 1991 | 1948250 |
| a structured model for vegetative growth and sporulation in bacillus thuringiensis. | a mathematical model has been developed for the delta-endotoxin producing bacillus thuringiensis. the structure of the model involves the processes taking place during vegetative growth, those leading to the initiation of sporulation under conditions of carbon and/or nitrogen limitation, and the sporulation events. the key features in the model are the pools of compounds, such as prpp, imp, adp/atp, gdp/gtp, pyrimidine nucleotides, nad/nadh2, amino acids, nucleic acids, cell wall, and vegetative ... | 1991 | 1929383 |
| cloning and characterization of two plasmids from bacillus thuringiensis in bacillus subtilis. | bacillus thuringiensis subspecies israliensis plasmids ptx14-1 and ptx14-3 were cloned and analyzed by southern blot hybridization for their replication mechanism in bacillus subtilis. the cloning of ptx14-1 into the replicon deficient vector pboe335 showed the usual characteristics of single-stranded dna plasmids, i.e., it generated circular single-stranded dna and high molecular weight (hmw) multimers. the other plasmid, ptx14-3, behaved differently; it generated neither single-stranded dna no ... | 1991 | 1924556 |
| binding of bacillus thuringiensis proteins to a laboratory-selected line of heliothis virescens. | a laboratory-selected colony of heliothis virescens displaying a 20- to 70-fold level of resistance to bacillus thuringiensis proteins was evaluated to identify mechanism(s) of resistance. brush-border membrane vesicles were isolated from larval midgut epithelium from the susceptible and resistant strains of h. virescens. two b. thuringiensis proteins, cryia(b) and cryia(c), were iodinated and shown to specifically bind to brush-border membrane vesicles of both insect strains. multiple changes i ... | 1991 | 1924353 |
| functional domains of bacillus thuringiensis insecticidal crystal proteins. refinement of heliothis virescens and trichoplusia ni specificity domains on cryia(c). | insecticidal crystal proteins (delta-endotoxins), cryia(a) and cryia(c), from bacillus thuringiensis are 82% homologous. despite this homology, cryia(c) was determined to have 10-fold more insecticidal activity toward heliothis virescens and trichoplusia ni than cryia(a). reciprocal recombinations between these two genes were performed by the homolog-scanning technique. the resultant mutants had different segments of their primary sequences exchanged. bioassays with toxin proteins from these mut ... | 1991 | 1917934 |
| identity of hemolysins produced by bacillus thuringiensis and bacillus cereus. | a hemolysin (bt-hemolysin) produced by bacillus thuringiensis var. kurstaki hd-1 producing crystalline toxin(s) was purified by successive treatments of ammonium sulfate (45-65%) and column chromatography using deae-cellulose, sephadex g-75 and kb-002 (a hydroxyapatite column for fast protein liquid chromatography). a hemolysin (bc-hemolysin) produced by b. cereus hg-6a was also purified by the same procedure. the purified bt-hemolysin and bc-hemolysin, both of which are thiol-activated hemolysi ... | 1991 | 1905656 |
| molecular cloning and characterization of two genes encoding sigma factors that direct transcription from a bacillus thuringiensis crystal protein gene promoter. | two sigma factors, sigma 35 and sigma 28, direct transcription from the bt i and bt ii promoters of the cryia(a) gene of bacillus thuringiensis; this gene encodes a lepidopteran-specific crystal protoxin. these sigma factors were biochemically characterized in previous work (k. l. brown and h. r. whiteley, proc. natl. acad. sci. usa 85:4166-4170, 1988; k. l. brown and h. r. whiteley, j. bacteriol. 172:6682-6688, 1990). in this paper, we describe the cloning of the genes encoding these two sigma ... | 1991 | 1904859 |
| effect of a 20-kilodalton protein from bacillus thuringiensis subsp. israelensis on production of the cyta protein by escherichia coli. | cyta, a 27-kda cytolytic crystal protein of bacillus thuringiensis subsp. israelensis, is produced only at very low levels by recombinant escherichia coli cells unless a 20-kda b. thuringiensis subsp. israelensis protein is also present (k. m. mclean and h. r. whiteley, j. bacteriol. 169:1017-1023, 1987; l. f. adams, j. e. visick, and h. r. whiteley, j. bacteriol. 171:521-530, 1989). however, the data reported here demonstrate that the 20-kda protein is not required for high-level cyta productio ... | 1991 | 1900280 |
| the toxic moiety of the bacillus thuringiensis protoxin undergoes a conformational change upon activation. | proteolytic processing of the 133-kda crystal protein (protoxin) from bacillus thuringiensis subsp. kurstaki yields a 67-kda insecticidal toxin. differential scanning calorimetry was used to investigate whether the toxic moiety in the protoxin molecule has the same conformation as activated toxin. compared to protoxin, toxin gives rise to a more complex endotherm which extends over a 10 degrees c broader temperature range and contains a component occurring at a substantially higher temperature t ... | 1991 | 1898414 |
| [genetic properties of the nonflagellar bacillus thuringiensis mutant]. | the nonflagellar mutant has been selected in bacillus thuringiensis strain 33-69 var. galleriae. the absence of flagella in the mutant cells is confirmed by electron microscopy, by the specific "trench transit" test. the mutant preserved the biochemical characteristics of the parent strain, possesses the same phage sensitivity but lower sporulation ability. fla+ phenotype is cotransduced with the his+ one in general transduction. | 1991 | 1896059 |
| a simple technique for determining relative toxicities of bacillus thuringiensis var. israelensis formulations against larval blackflies (diptera: simuliidae). | a laboratory system for assaying the potency of bacillus thuringiensis var. israelensis formulations against larval blackflies was developed. an orbital shaker was used to create a water current in 250-ml erlenmeyer flasks containing the test larvae. this system produced dose-mortality relationships with acceptable statistical parameters. | 1991 | 1895092 |
| aerially applied, liquid bacillus thuringiensis var. israelensis (h-14) for control of spring aedes mosquitoes in michigan. | liquid b.t.i. (vectobac 12as), when mixed with water at a 1:3 ratio and applied by helicopter at a rate of 1.17 liters b.t.i. (4.68 liters mix) per ha, was 99% effective in a small (mass median diameter on dye cards: 178 microns) droplet size but ineffective (65%) in a large (553 microns) droplet against spring aedes larvae in snowmelt pools. there were about 6 times as many smaller droplets as larger ones impacting the treated pools, which probably explained the difference in effectiveness for ... | 1991 | 1895091 |
| perspectives on management of pestiferous chironomidae (diptera), an emerging global problem. | in recent years, adult chironomidae emerging from some urban natural or man-made habitats have increasingly posed a variety of nuisance and economic problems, and in some situations medical problems to humans in different parts of the world. although there are an estimated 4,000 or more species of chironomid midges worldwide, less than 100 species have been reported to be pestiferous. among midge control methods, numerous laboratory and field studies have been conducted on the use of organochlor ... | 1991 | 1895084 |
| compatibility of bacillus thuringiensis var. israelensis and bacillus sphaericus with the fungal pathogen lagenidium giganteum (oomycetes: lagenidiales). | larvae of culex quinquefasciatus were exposed to infection by lagenidium giganteum and various concentrations of b.t.i. or b. sphaericus. the resulting larval mortalities, percentages of infected dead larvae and percentages of larval body regions containing the fungus were compared. overall, the effectiveness of lagenidum giganteum against the larvae was not significantly affected by the presence of b.t.i. or b. sphaericus, and the fungal and bacterial agents were compatible. in experiments usin ... | 1991 | 1895077 |
| field trials with vectolex (bacillus sphaericus) and vectobac (bacillus thuringiensis (h-14)) against anopheles gambiae and culex quinquefasciatus breeding in zaire. | under field conditions in kinshasa, zaire, an aqueous suspension of bacillus thuringiensis (h-14), vectobac (12-as), lost most of its larvicidal activity at all concentrations after 48 h against culex quinquefasciatus breeding in polluted gutter water and anopheles gambiae breeding in clear water irrigation ponds. however, good control of cx. quinquefasciatus was obtained using a granular formulation of b. sphaericus, vectolex-g (abg-6185), at concentrations of 10-30 kg/ha. high concentrations o ... | 1991 | 1895075 |
| viral and bacterial pathogens of insects. | 1991 | 1887272 | |
| two new isolates of bacillus thuringiensis pathogenic to spodoptera litura. | both the standard bacillus thuringiensis kurstaki (hd-1) and the formulated commercial product resulted from this strain have shown limited pathogenicity against the tobacco cutworm (spodoptera litura). however, two new isolates of bacillus thuringiensis (k-2074 and k-2178) isolated from taiwan have been identified through an active screening program to be highly pathogenic against the tobacco cutworm. in this paper, we present results of characterization and the pathogenicity of these two new i ... | 1991 | 1885923 |
| characterization and comparative sequence analysis of replication origins from three large bacillus thuringiensis plasmids. | the replication origins of three large bacillus thuringiensis plasmids, derived from b. thuringiensis hd263 subsp. kurstaki, have been cloned in escherichia coli and sequenced. the replication origins, designated ori 43, ori 44, and ori 60, were isolated from plasmids of 43, 44, and 60 mda, respectively. each cloned replication origin exhibits incompatibility with the resident b. thuringiensis plasmid from which it was derived. recombinant plasmids containing the three replication origins varied ... | 1991 | 1885511 |
| effect of nutritive elements on the extracellular protein of different bacillus strains, toxic to mosquito larvae. | the effect of 5 nutritional elements (glucose, peptone, yeast extract, beef extract and lactic acid) on the growth of the 4 tested bacillus strains (bacillus thuringiensis bactimos 78, b. thuringiensis ips 82, b. sphaericus solvay 85 and b. sphaericus rb 80) as well as on the concentration of their extracellular proteins were studied. the nutritive elements were individually tested either dissolved in distilled water or in a buffer base. results indicated that the bacterial growth was higher whe ... | 1991 | 1875084 |
| effect of certain formulations of the bacterial larvicide, bacillus thuringiensis, serotype h-14 on culex pipiens l. in egypt. | 1991 | 1875070 | |
| [inversion polymorphism in malaria mosquito anopheles messeae. part x. resistance of larvae with different genotypes to toxins of crystal-forming bacteria bacillus thuringiensis subsp. israelensis (serovar h14)]. | insensibility of larvae with different chromosomal inversions to the toxins of bacillus thuringiensis subsp. israelensis (bti) was examined. it has been shown that larvae with inversion combinations xl0(xl1)2r0-3r0-3l0 had greater variability after treatment with bti than larvae with inversions xl1(xl2)2r1-3r1-3l1(3l0). the former inversion combinations were previously shown to dominate in the south of the species area and to be supported by k-selection. the latter inversion combinations form "n ... | 1991 | 1874433 |
| shuttle vectors containing a multiple cloning site and a lacz alpha gene for conjugal transfer of dna from escherichia coli to gram-positive bacteria. | the mobilizable shuttle cloning vectors, pat18 and pat19, are composed of: (i) the replication origins of puc and of the broad-host-range enterococcal plasmid pam beta 1; (ii) an erythromycin-resistance-encoding gene expressed in gram- and gram+ bacteria; (iii) the transfer origin of the incp plasmid rk2; and (iv) the multiple cloning site and the lacz alpha reporter gene of puc18 (pat18) and puc19 (pat19). these 6.6-kb plasmids contain ten unique cloning sites that allow screening of derivative ... | 1991 | 1864514 |
| analysis of unstable rna transcripts of insecticidal crystal protein genes of bacillus thuringiensis in transgenic plants and electroporated protoplasts. | we have examined expression of several insecticidal crystal protein (icp) genes of bacillus thuringiensis in transgenic tobacco plants and electroporated carrot protoplasts. we determined that low levels of lepidopteran toxin cryia(b) icp gene expression in plants and electroporated carrot cells is due to rna instability. we used a series of 3' deleted by cryia(b) constructs directed by the cauliflower mosaic virus 35s promoter to demonstrate that this instability is minimally contained in the f ... | 1991 | 1863758 |
| characterization and sequence analysis of a small plasmid from bacillus thuringiensis var. kurstaki strain hd1-dipel. | the complete nucleotide sequence of a small (2.055 kb) plasmid phd2 from bacillus thuringiensis var. kurstaki strain hd1-dipel was obtained. the sequence encoded two open reading frames (orfs) which corresponded to polypeptides of mr 26,447 and 9122. comparison of the sequence with those obtained for other plasmids from gram-positive organisms suggested that phd2 may belong to the extensive and highly interrelated family of plasmids exhibiting replication via a ssdna intermediate: a putative nic ... | 1991 | 1857751 |
| isolation of mosquito-pathogenic bacillus sphaericus & b. thuringiensis from the root surface of hydrophytes. | attempts were made to isolate b. sphaericus and b. thuringiensis active against mosquito larvae from the root surface of hydrophytes. out of 139 samples processed, 86 b. sphaericus and 23 b. thuringiensis isolates were obtained. sixty two of the b. sphaericus isolates belonged to the serotype h5a5b, 2 to h6 and 22 isolates did not agglutinate with any of the 6 antisera tested. twenty of the b. thuringiensis isolates belonged to the h14 serotype, 1 each to the h10 and h17 serotype(s) and 1 to an ... | 1991 | 1855819 |
| cloning and expression of bacillus thuringiensis israelensis delta-endotoxin dna in b. sphaericus. | bacillus thuringiensis israelensis delta-endotoxin genes were cloned into bacillus sphaericus 2362, producing stable transformants reacting with antibody to the 28- and 65-kda b. thuringiensis israelensis crystal proteins and approximately 10 times more toxic to aedes mosquito larvae than the original host strain. the lc50 after 48 hr of exposure of aedes larvae to the most active transformed clone was 0.19 microgram/ml, compared with an lc50 of 1.9 microgram/ml for b. sphaericus 2362 and less t ... | 1991 | 1850771 |
| rapid analysis of glycolipid anchors in amphiphilic dimers of acetylcholinesterases. | 1. we describe two simple procedures for the rapid identification of certain structural features of glycolipid anchors in acetylcholinesterases (aches). 2. treatment with alkaline hydroxylamine (that cleaves ester-linked acyl chains but not ether-linked alkyl chains) converts molecules possessing a diacylglycerol, but not those with an alkylacylglycerol, into hydrophilic derivatives. aches in human and bovine erythrocytes possess an alkylacylglycerol (roberts et al., j. biol. chem. 263:18766-187 ... | 1991 | 1849455 |
| phosphatidylinositol-specific phospholipase c induces biosynthesis of acetylcholinesterase via diacylglycerol in schistosoma mansoni. | we have previously shown that two ectoenzymes, acetylcholinesterase (ache) and alkaline phosphatase, are released from the surface and from particulate fractions of the parasite schistosoma mansoni, by a phosphatidylinositol-specific phospholipase c (ptdins-plc) of bacterial origin. exposure to ptdins-plc not only removes large amounts of ache from the surface of intact, viable schistosoma in culture, but is accompanied by a concomitant increase in overall levels of ache in the parasite. the sam ... | 1991 | 1847873 |
| two structural domains as a general fold of the toxic fragment of the bacillus thuringiensis delta-endotoxins. | the unfolding by guanidine hydrochloride of the toxic fragment of a bacillus thuringiensis toxin belonging to the cryic class reveals a two-step denaturation under both acid and alkaline conditions. this demonstrates the existence of two structural domains as building blocks for this toxin. protease digests performed on a cryia(b) and cryic b. thuringiensis toxin, under native and partially denatured conditions, confirm this conclusion. whereas the native cryic toxin is completely protease resis ... | 1991 | 1847865 |
| listeria monocytogenes mutants lacking phosphatidylinositol-specific phospholipase c are avirulent. | a number of bacterial species secrete phosphatidylinositol-specific phospholipase c (pi-plc). in this report, we show that the facultative intracellular bacterial pathogen, listeria monocytogenes, contains a gene, plca, predicting a polypeptide with 31% amino acid identity to a bacillus thuringiensis pi-plc. accordingly, l. monocytogenes secretes pi-plc activity, while a mutant with a transposon insertion in plca lacks detectable pi-plc activity. in addition, expression of plca in b. subtilis re ... | 1991 | 1847723 |
| release of a membrane surface glycoprotein from human platelets by phosphatidylinositol specific phospholipase(s) c. | phosphatidylinositol (pi) specific phospholipase c (piase c) treatment of human platelets caused release of a surface glycoprotein in the medium. human blood platelets were isolated by low speed centrifugation and surface glycoproteins were labelled with periodate/[3h]borohydride procedure. intact surface-labelled platelets were treated with piase c purified from culture filtrates of staphylococcus aureus (sa) or bacillus thuringiensis (bt). after piase c treatments platelets were spun at low sp ... | 1991 | 1847299 |
| the mechanism of sunlight-mediated inactivation of bacillus thuringiensis crystals. | detailed photostability studies were carried out using purified delta-endotoxin crystals from bacillus thuringiensis subspecies hd-1 and hd-73. the mechanism and time course of sunlight inactivation was investigated by: (a) monitoring the tryptophan damage in the intact crystals by raman spectroscopy, (b) amino acid analysis and (c) biological assays using insects. the results demonstrate that, for purified hd-1 or hd-73 crystals, the 300-380 nm range of the solar spectrum is largely responsible ... | 1991 | 1846530 |
| mechanism of inhibition of adenylate cyclase by phospholipase c-catalyzed hydrolysis of phosphatidylcholine. involvement of a pertussis toxin-sensitive g protein and protein kinase c. | the phospholipase c-mediated hydrolysis of phosphatidylcholine has been shown recently to be activated by a number of agonists. muscarinic receptors, which trigger various signal transduction mechanisms including inhibition of adenylate cyclase through gi, have been shown to be potent stimulants of this novel phospholipid degradative pathway. we demonstrate here, by exogenous addition of bacillus cereus phosphatidylcholine-hydrolyzing phospholipase c, that phosphatidylcholine breakdown mimics th ... | 1991 | 1845988 |
| [implications of biological pest and parasite control for environment]. | biological control of parasites, vectors and pests must consider safety to non-target organisms and to the environment. the who safety procedure was discussed in respect to such agents as bacillus thuringiensis, romanomermis culicivorax, gambusia affinis and others. monitoring of the environment in which biological control treatments are performed is necessary to secure safety requirements as well as the efficiency of biological control programmes. | 1991 | 1844787 |
| plasmid vectors for 'unclonable' dna constructions. | 1991 | 1841362 | |
| expression of the cryib crystal protein gene of bacillus thuringiensis. | the cryib gene of bacillus thuringiensis subsp. thuringiensis hd-2 codes for a mr 139492 protein that is lethal to certain lepidopteran larvae. we used primer extension to map transcriptional initiation sites and found that cryib was transcribed from two sites that are activated at different times during sporulation. the presumed promoter regions for the two start sites are very similar to the two promoters preceding the cryia (a) gene, and the in vivo transcriptional start sites were found to b ... | 1991 | 1840641 |
| cloning of a tumor-associated antigen: mov18 and mov19 antibodies recognize a folate-binding protein. | monoclonal antibodies mov18 and mov19, raised against a membrane preparation of an ovarian carcinoma surgical specimen, react with a surface antigen present on the majority of nonmucinous ovarian malignant tumors tested but not with normal adult tissue (s. miotti, s. canevari, s. ménard, d. mezzanzanica, g. porro, s. m. pupa, m. regazzoni, e. tagliabue, and m. i. colnaghi, int. j. cancer, 39: 297-303, 1987). this surface antigen was purified as a soluble glycoprotein (molecular mass, 36-38 kda) ... | 1991 | 1840502 |
| aminoacylase i is not a glycolipid-anchored ectoenzyme in pig kidney. | subcellular fractionation of pig kidney cortex revealed that aminoacylase i (ec 3.5.1.14, n-acyl-l-amino-acid aminohydrolase) is predominantly a soluble enzyme with only 0.5% of the total activity being recovered in the membrane fraction. the aminoacylase i activity associated with the membrane preparations displayed neither rapid release following incubation with phosphatidylinositol-specific phospholipase c from bacillus thuringiensis nor the distinctive differential pattern of detergent solub ... | 1991 | 1825788 |
| [usefulness of thuridan in the control of fly larvae in animal houses]. | the studies were carried out in a pig farm and in a dairy cattle farm in south poland. thuridan was applied as 0.3% suspension in 3 replications in 7 days interval. the efficacy of thuridan was established using fly--catchers which were hung on the same places--once before and three times after thuridan was used. in the animal houses 86% less flies were found. | 1991 | 1823488 |
| [insecticidal activity of various strains of bacillus against larvae of houseflies (musca domestica)]. | insecticidal activity of b. thuringiensis subsp. morrisoni and b. thuringiensis subsp. darmstadiensis as well as b. sphaericus 2362 and 2297 was evaluated against larvae of the house fly (musca domestica) under laboratory condition. the activity of all tested strains was similar, lc50 ranges from 4 x 10(7) to 1 x 10(8) spores/ml. the higher spores concentration (2 x 10(9)) caused ca 70 per cent mortality. the relative low sensitivity of house fly larvae could results from weakly alkalic ph of th ... | 1991 | 1822051 |
| laboratory evaluation of bacillus thuringiensis h-14 against aedes aegypti larvae in the northeast region of thailand. | laboratory bioassays using a preparation of bacillus thuringiensis h-14 (bt.h-14), namely skeetal were conducted to determine their effectiveness against late 3rd/early 4th instar larvae of aedes aegypti. the larvae were collected from municipal areas in 7 provinces, namely burirum, roi-et, khon kaen, ubol ratchatani, nakorn phanom, surin and nakorn ratchasima, in the northeast of thailand. it was found that for skeetal, lc50 ranged from 128 to 151 nl/l (average 143) and lc90 ranged from 254 to ... | 1991 | 1818396 |
| isolation and cloning of bacillus thuringiensis var kurstaki hd73 toxin gene and construction of a chimaeric gene for expression in plants. | necessity for the production of transgenic crop plants of india, capable of expression of insecticidal bt protein in plant to combat lepidopteran pest damage has been strongly felt. bacillus thuringiensis kurstaki hd73 crystal protein coded by cryia(c)73 gene has been found to be sufficiently effective against the major pests of jute and chickpea. an attempt to isolate the gene and make its use in a chimaeric gene construct for expression in plant was carried out. the plasmid cryia(c)73 gene was ... | 1991 | 1816076 |
| long-term effects of bacillus thuringiensis subsp. israelensis on aedes aegypti. | immediate (24 hours exposure) and long-term (until the emergence of the adults) effects of different doses of a primary powder of bacillus thuringiensis subsp. israelensis (b.t.i.) against first and second instar aedes aegypti larvae were monitored. the long-term effect was dose-dependent and was materialized by a prolongation of the preimaginal development and continuous cumulative mortality until the emergence of the adults. mortality values were higher during the fourth larval instar and the ... | 1991 | 1802053 |
| the effects of coexisting lipids on the action of bacillus thuringiensis phosphatidylinositol-specific phospholipase c toward liposomal substrate. | the hydrolytic activity of phosphatidylinositol (pi)-specific phospholipase c (pi-plc) from bacillus thuringiensis was studied in detail toward mixed liposomes consisting of pi and one of other phospholipids and cholesterol. among pi-liposomes, small unilamellar vesicles (suv) were the most sensitive to pi-plc; the enzymatic hydrolysis of pi in suv was not less than 10-fold that in large unilamellar vesicles (luv) or in multilamellar vesicles (mlv). thus, in a survey of the effects of coexisting ... | 1991 | 1799944 |
| action of phosphatidylinositol-specific phospholipase c from bacillus thuringiensis is significantly influenced by coexisting lipids in substrate-detergent micelles. | the effects of phosphatidylcholine (pc), phosphatidylethanolamine (pe), sphingomyelin (sm), and cholesterol on the activity of phosphatidylinositol-specific phospholipase c (pi-plc) from bacillus thuringiensis were studied in detail in phosphatidylinositol (pi)/detergent mixed micelles. by addition of pc, the enzymatic hydrolysis of pi was significantly stimulated in pi/triton x-100 as well as pi/sodium deoxycholate (sdc) mixed micelles. sm stimulated enzyme activity toward pi/triton x-100 micel ... | 1991 | 1797426 |
| [a comparison of some malarial mosquito species in their reaction to bacterial insecticides]. | considerable differences have been detected in the sensitivity of various anopheles species to bacterial insecticides. these differences might be associated with features in larval nutrition and do not depend on their size and taxonomic species position. an. pulcherrimus or an. sacharovi and an. stephensi species are suggested as the most suitable test objects for the representatives of the given genus. | 1991 | 1795691 |
| [the autoselection of neustonic forms of bacteria]. | self-breeding of neuston forms of methylobacterium sp., pseudomonas putida bc-2, alcaligenes paradoxus bc-1, bacillus thuringiensis var. israilensis bacteria as well as of a mixed culture of methylotrophs is shown possible. in spite of ability of hydrophobicity of the cell surface the suggested method of self-breeding may be used to perfect properties of larvicidal biopreparations, and bacterial preparations which intensify self-purification of water bodies. | 1991 | 1791780 |
| delayed mortality and morphogenetic anomalies induced by the microbial control agent bacillus thuringiensis ser. (h-14) in culex quinquefasciatus. | sublethal concentrations of bacillus thuringiensis ser. h-14 were applied to early 4th-instar larvae of culex quinquefasciatus to assess mortality and morphogenetic aberrations in larvae, pupae and adults. at the 24 h lc10, lc25, lc50 and lc80, additional mortality occurred in surviving larvae beyond a 24 h exposure period. the cumulative mortalities increased daily and the overall mortality of larvae up to 7 days posttreatment were 12, 73, 82 and 96% at the indicated concentrations, respectivel ... | 1991 | 1791452 |
| cloning and expression of the lepidopteran toxin produced by bacillus thuringiensis var sotto in escherichia coli. | during sporulation, bacillus thuringiensis var. sotto produces a parasporal crystalline protein which is toxic for the silk-worm, bombyx mori and the cotton leaf worm, spodoptera littoralis. the gene coding this crystal protein is present in a single plasmid. the plasmid dna was isolated, purified and physically mapped using restriction endonuclease enzymes (r.e.). the gene coding the delta-endotoxin was inserted into escherichia coli-jm103, using cloning vector puc8. transformed e. coli cells w ... | 1991 | 1791407 |
| frass failure and pupation failure as quantal measurements of bacillus thuringiensis toxicity to lepidoptera. | 1991 | 1787331 | |
| bioencapsulation and delivery to mosquito larvae of bacillus thuringiensis h14 toxicity by tetrahymena pyriformis. | 1991 | 1787330 | |
| two novel strains of bacillus thuringiensis toxic to coleopterans. | two novel strains of bacillus thuringiensis were isolated from native habitats by the use of genes coding for proteins toxic to coleopterans (cryiii genes) as hybridization probes. strain eg2838 (isolated by the use of the cryiiia probe) contained a cryiiia-hybridizing plasmid of approximately 100 mda and synthesized crystal proteins of approximately 200 (doublet), 74, 70, 32, and 28 kda. strain eg4961 (isolated by the use of a cryiiia-related probe) contained a cryiiia-hybridizing plasmid of ap ... | 1991 | 1781691 |
| prediction of insecticidal activity of bacillus thuringiensis strains by polymerase chain reaction product profiles. | a rapid analysis of bacillus thuringiensis strains predictive of insecticidal activity was established by using polymerase chain reaction (pcr) technology. primers specific to regions of high homology within genes encoding three major classes of b. thuringiensis crystal proteins were used to generate a pcr product profile characteristic of each insecticidal class. predictions of insecticidal activity were made on the basis of the electrophoretic patterns of the pcr products. included in the scre ... | 1991 | 1781673 |
| [the flotation characteristics of bacillus cells and spores]. | variations in hydrophobicity of the surface of bacillary cells and their capacity to flotation in the process of batch cultivation have been studied. it is shown that hydrophobicity of the cell surface increases in the course of batch cultivation of bacillus thuringiensis, b. licheniformis and b. megaterium. hydrophobicity of spores of the mentioned cultures is considerably higher than that of the vegetative cells. the increase of hydrophobicity of bacillary cells positively correlated with thei ... | 1991 | 1779906 |
| production & formulation of bacillus thuringiensis var. israelensis & b. sphaericus 1593. | three fermentation media each for bulk growth of b. thuringiensis var. israelensis and b. sphaericus 1593 were formulated using defatted groundnut cake (arachis hypogea) as the first nitrogen source and gram flour (cicer arientinum), soy bean (glycine max) and defatted milk powder as the second nitrogen source. medium containing gram flour showed highest toxicity (14.45 micrograms/l) in case of b. thuringiensis var. israelensis whereas medium containing milk powder was found to be highly toxic w ... | 1991 | 1778620 |
| cytotoxicity of a cloned bacillus thuringiensis subsp. israelensis cryivb toxin to an aedes aegypti cell line. | a cloned cryivb toxin was purified from a cured strain of bacillus thuringiensis (bt) containing the cryivb gene on the recombinant plasmid cam135. solubilized protoxin was treated with aedes gut extract or trypsin for varying times and tested for toxicity in vitro on three dipteran and one lepidopteran cell line. treatment with the aedes extract but not trypsin, produced an active toxin which lysed only aedes aegypti cells out of those tested. this activation was time-dependent reaching a maxim ... | 1991 | 1769533 |