| a method for the determination of bacterial spore dna content based on isotopic labelling, spore germination and diphenylamine assay; ploidy of spores of several bacillus species. | a reliable method for measuring the spore dna content, based on radioactive dna labelling, spore germination in absence of dna replication and diphenylamine assay, was developed. the accuracy of the method, within 10-15%, is adequate for determining the number of chromosomes per spore, provided that the genome size is known. b subtilis spores were shown to be invariably monogenomic, while those of larger bacilli bacillus megaterium, bacillus cereus and bacillus thuringiensis, often, if not invar ... | 1992 | 1391052 |
| serotyping of bacillus thuringiensis environmental isolates by extracellular heat-stable somatic antigens. | a total of 525 bacillus thuringiensis environmental isolates, belonging to the five flagellar (h) serovars (alesti, sotto, kenyae, aizawai, and morrisoni), were serotyped by extracellular heat-stable somatic antigens (hssas). the isolates belonging to a given h serovar were assigned to a single hssa serogroup at a high frequency, 87-100%. this indicates that the extent of hssa variation within a single h serovar is small in the field populations of these b. thuringiensis serovars. | 1992 | 1393835 |
| mode of replication, size and distribution of naturally occurring plasmids in bacillus thuringiensis. | cloned replication origin regions, derived from both small (4.9-7.5 mda) and large (43-60 mda) plasmids of bacillus thuringiensis subspecies kurstaki strains hd73 and hd263 were used as hybridization probes in a southern-blot analysis to assess both the size and horizontal distribution of native plasmid replicon groups among different subspecies of b. thuringiensis. in general, resident plasmids hybridizing to the replication origin regions derived from strains hd263 and hd73 were more commonly ... | 1992 | 1398029 |
| [site-specific restrictases from bacillus thuringiensis var. kumantoensis]. | the efficiency of bacteriophages cp-54 and cp-55 plating on bacillus thuringiensis var. kumantoensis h18 (kum) is decreased about 10-fold as compared with the efficiency of plating on bacillus thuringiensis var. galleriae h5 (gal). bacteriophages having propagated for one cycle in kum cells might be further grown in this strain without growth restriction. two site-specific restriction enzymes isolated from bacillus thuringiensis var. kumantoensis were designated btki and btkii. the endonuclease ... | 1992 | 1320199 |
| safety of bacillus thuringiensis for earthworms. | | 1975 | 1151099 |
| purification and crystallization of insecticidal delta-endotoxin cryiiib2 from bacillus thuringiensis. | cryiiib2, an insecticidal protein from bacillus thuringiensis has been crystallized from 0.6 m nabr and hepes buffer at ph 7.0 and x-ray diffraction data collected on a native crystal to 2.4 a. the insecticidal protein was obtained from a bacillus thuringiensis (bt) strain eg7231. crystals of the endotoxin are orthorhombic, space group c2221, with unit cell dimensions of a = 122.44, b = 131.81, and c = 105.37 a. a unit cell contains one molecule of the 67,000 da endotoxin per asymmetric unit. | 1992 | 1329083 |
| glycolipid-anchored acetylcholinesterases from rabbit lymphocytes and erythrocytes differ in their sensitivity to phosphatidylinositol-specific phospholipase c. | the type of membrane association of acetylcholinesterase (ache, ec 3.1.1.7) was studied in rabbit lymphocytes and erythrocytes. in both cases, the unique ache molecular form was an amphiphilic dimer (referred to as g2a) anchored in the membrane by a glycosylphosphatidylinositol. in lymphocytes, g2a ache was directly converted into its hydrophilic g2h counterpart by a treatment with bacillus thuringiensis phosphatidylinositol-phospholipase c (pi-plc, ec 3.1.4.10). in erythrocytes, ache was resist ... | 1992 | 1329966 |
| structural comparisons between the soluble and the gpi-anchored forms of the paramecium temperature-specific 156g surface antigen. | biosynthetic labelling experiments performed on p primaurelia strain 156, expressing the temperature-specific g surface antigen, 156g sag, demonstrated that the purified 156g sag contained the components characteristic of a gpi-anchor. [3h]ethanolamine, [3h]myo-inositol, [32p]phosphoric acid and [3h]myristic acid could all be incorporated into the surface antigen. myristic acid labelling was lost after treatment in vitro with bacillus thuringiensis phosphatidylinositol-specific phospholipase c ( ... | 1992 | 1335331 |
| the parasporal inclusion of bacillus thuringiensis subsp. shandongiensis: characterization and screening for insecticidal activity. | the parasporal body of bacillus thuringiensis subsp. shandongiensis was characterized in terms of its structure, protein composition, and toxicological properties against several types of insects. the crystals of b. thuringiensis shandongiensis appear to consist of a major protein of 144 kda present in an spherical inclusion, as determined by transmission electron microscopy, titration curve analysis, and sds-page of the solubilized crystals. a second protein of ca. 60 kda is present in trace am ... | 1992 | 1351504 |
| involvement of a possible chaperonin in the efficient expression of a cloned cryiia delta-endotoxin gene in bacillus thuringiensis. | the bacillus thuringiensis cryiia delta-endotoxin gene is found as the third-gene in a three-gene operon, with a sporulation-dependent promoter lying upstream of the first gene, orf1. we show here that the polypeptide product of the middle gene (orf2) is required for efficient expression of the toxin gene. in the absence of a functional orf2 polypeptide the toxin does not form the crystalline inclusions characteristic of other known bacillus thuringiensis toxins. we discuss the importance of thi ... | 1992 | 1352615 |
| a broad-spectrum cytolytic toxin from bacillus thuringiensis var. kyushuensis. | bacillus thuringiensis (bt) var. kyushuensis synthesizes a mosquitocidal crystalline inclusion containing several proteins ranging from 140 to 14 kda. we have identified a 25 kda protein protoxin in this inclusion which is not cytolytic, but when activated proteolytically to 23-22 kda products is cytolytic to mosquito, lepidopteran and mammalian cells, can release entrapped glucose from liposomes and forms cation-selective channels in a planar lipid bilayer. this broad-spectrum cytolytic toxin i ... | 1992 | 1355907 |
| acetylcholinesterases of the nematode steinernema carpocapsae. characterization of two types of amphiphilic forms differing in their mode of membrane association. | we analyzed the molecular forms of acetylcholinesterase (ache) in the nematode steinernema carpocapsae. two major aches are involved in acetylcholine hydrolysis. the first class of ache is highly sensitive to eserine (ic50 = 0.05 microm). the corresponding molecular forms are: an amphiphilic 14s form converted into a hydrophilic 14.5s form by mild proteolysis and two hydrophilic 12s and 7s forms. reduction of the amphiphilic 14s form with 10 mm dithiothreitol produces hydrophilic 7s and 4s forms ... | 1992 | 1323459 |
| effects of ph on conformational properties related to the toxicity of bacillus thuringiensis delta-endotoxin. | the delta-endotoxin of bacillus thuringiensis subspecies kurstaki is an intracellular crystalline proteinaceous inclusion which, upon ingestion, is toxic to lepidopteran insects. upon dissolution at ph > 9 it yields a protein subunit called protoxin. under appropriate conditions, protoxin is hydrolyzed to a toxin molecule, which is responsible for killing the insect. it is known that this toxic activity decreases considerably above ph 10. in this study, circular dichroism spectroscopy has been u ... | 1992 | 1327158 |
| evaluation of synergism among bacillus thuringiensis toxins. | a simple test for synergism among toxins is described and applied to previously reported data on independent and joint toxicities of insecticidal proteins from bacillus thuringiensis. the analysis shows synergism between a 27-kda (cyta) toxin and 130- or 65-kda (cryiv) toxins from b. thuringiensis subsp. israelensis against aedes aegypti larvae. no positive synergism between 130- and 65-kda toxins or among three cryia toxins tested against seven species of lepidoptera occurred. comparisons with ... | 1992 | 1444368 |
| [influence of carbon sources on the biological activity and morphology of bacillus thuringiensis parasporal crystals]. | the influence of the carbon source on biological activity and morphological properties of the parasporal crystals of bacillus thuringiensis subsp. kurstaki cultivated on three different media has been studied. biological activity of delta-endotoxins contained in crystals was tested according to their impact on insects and microorganisms. variations in carbon sources composition resulted in changes of biological activity and morphology of crystals, caused by alterations in synthesis rate of vario ... | 1992 | 1474939 |
| [comparative electron microscopic study of bacillus thuringiensis cells grown in a chemostat]. | it has been shown that the culture of bacillus thuringiensis subsp. gall. 69-6 dissociates into r- and s-variants in chemostat. although under some conditions the sporogenesis and the synthesis of s-variant toxin began two hours earlier than these processes in r-variant cells which were observed, respectively, after 10 or 12 hours from the beginning of the experiment, the intensities of sporogenesis and toxin production as well as the exit of spores and toxin excretion from cells were similar af ... | 1992 | 1474944 |
| processing of delta-endotoxin from bacillus thuringiensis subsp. kurstaki hd-1 and hd-73 by gut juices of various insect larvae. | midgut juices were prepared from adoxophyes sp., smaller tea tortrix (stt); bombyx mori, silkworm (sw); spodoptera litura, common cutworm (ccw); plutella xylostella, diamondback moth (dbm); and musca domestica, housefly (hf) and immobilized onto sepharose 4b. delta-endotoxins (icps) from bacillus thuringiensis subsp. kurstaki hd-1 and hd-73 were digested by these immobilized gut juice proteases. all gut juices tested derived relatively proteolytic resistant cores from icp. the molecular sizes of ... | 1992 | 1328398 |
| the delta-endotoxin protein family displays a hydrophobic motif that might be implicated in toxicity. | a computer-based analysis of hydropathy and surface probability of representative members of each class of the cry family of proteins was performed. a highly conserved hydrophobic motif within the previously described block, d2, is present not only in lepidopteran toxin genes but also in toxins active against diptera and coleoptera. an interesting feature of this hydrophobic motif is the presence of an aspartic residue (highly hydrophilic) in its middle part. comparison with the amino acid seque ... | 1992 | 1328811 |
| [molecular cloning and identification of 130kd mosquitocidal protein gene of bacillus thuringiensis var. israelensis (bti)]. | the location of 130kd mosquitocidal protein gene of bti 4q5 strain on its 75md plasmid was confirmed by southern hybridization using a 18-base oligonucleotide probe. the crystal protein containing the component of 130kd toxic protein was purified. the crystal protein exhibiting the mosquitocidal activity against larvae of aedes aegypti was shown by bioassay. the purified 75md plasmid dna of bti 4q5 strain was completely digested with hindiii restriction enzyme, ligated with the vector puc18 and ... | 1992 | 1481529 |
| toxicity and residual action of the photoactivated compound, cyano-alpha-terthienyl, and its efficacy for reducing pre-imaginal populations of mosquitoes. | the photoactivated compound, cyano-alpha-terthienyl (cyano-alpha-t), was highly toxic to pre-imagines of the mosquitoes culex restuans, cx. tarsalis and culiseta inornata when synergized with piperonyl butoxide (pbo). lethal concentrations for 50% mortality, determined during an outdoor trial using caged fourth-instar culex spp. larvae, were 19.4, 15.4 and 12.9 g/ha at 24, 48 and 72 h after treatment, respectively. no residual activity of cyano-alpha-t was observed beyond 24 h following treatmen ... | 1992 | 1359007 |
| the occurrence of disporous bacillus thuringiensis cells. | ultrathin sections of sporulating bacillus thuringiensis were examined in a transmission electron microscope. less than 1% of the about 2,000 approximately sagittal sections of the bacterial cells examined contained two endospores per cell. this finding clarifies the majority of textbook and research reports (which tend to be ambiguous), contradicts several of the most recent textbook reports, and confirms three unillustrated textbook reports, in relation to the occurrence of disporous bacilli. ... | 1992 | 1497331 |
| t cell maturation stage-linked heterogeneity of the glycosylphosphatidylinositol membrane anchor of thy-1. | we showed that some of thy-1 molecules on murine thymocytes are resistant to phosphatidylinositol-specific phospholipase c (pi-plc) derived from bacillus thuringiensis. both immature thymocytes with low cd3 expression and mature thymic t lymphocytes with high cd3 expression carried the pi-plc-resistant thy-1, and the pi-plc-sensitivity of thy-1 extensively varied among thymocyte subpopulations. in contrast, the same pi-plc fully hydrolysed the anchor of thy-1 on peripheral t lymphocytes. when th ... | 1992 | 1360444 |
| sensitivity of mosquito-pathogenic bacterial strains to various antibodies. | four strains of bacillus sphaericus, 1593, 2362, 9001 and 9002, b. thuringiensis h-14 and b. thuringiensis neoleonensis were tested for sensitivity against 18 antibiotics. the results revealed that all the four strains of b. sphaericus are resistant to colistin, nalidixic acid, polymyxin b and streptomycin. however, b. thuringiensis h-14 was resistant to 9 antibiotics, viz. ampicillin, cephalexin, carbenicillin, co-trimoxazole, colistin, cloxacillin, penicillin, nitrofurantoin and polymyxin b wh ... | 1992 | 1363415 |
| [an evaluation of the genotoxicity activity of the microbial preparation bulmoscide]. | the genotoxic activity of the microbial preparation bulmoscid "in vivo" for somatic cells of mammals is studied by micronucleus method in marrow of mice. the experiments are performed on inbred mice c57bl6 of both sexes at unrepeated oral introduction of the preparation in two doses: 2200 mg/kg-1 (2.64.10(10) cells kg-1), and 1100 mg/kg-1 (1.32.10(10) cells kg-1) presenting 80% and respectively 40% of the unrepeated maximum tolerable dose of "bulmoscid" for mice (2750 mg/kg-1). the genotoxic ind ... | 1992 | 1364531 |
| [the acute toxicity of the microbial preparation bulmoscide]. | the acute toxicity of a new bulgarian microbial preparation bulmoscid on the basis of bacillus thuringiensis h-14 in the conditions of oral, dermal, inhalation and intraperitoneal introduction in experimental animals is determined. the assessment of toxicity is made by using toxicometric, integral, hematologic, histologic and microbiologic methods in accordance with bulgarian and international criteria and standards. it is established, that the preparation bulmoscid introduced orally in dose 550 ... | 1992 | 1364532 |
| insect resistant cotton plants. | we have expressed truncated forms of the insect control protein genes of bacillus thuringiensis var. kurstaki hd-1(cryia(b) and hd-73 (cryia(c) in cotton plants at levels that provided effective control of agronomically important lepidopteran insect pests. total protection from insect damage of leaf tissue from these plants was observed in laboratory assays when tested with two lepidopteran insects, an insect relatively sensitive to the b.t.k. insect control protein, trichoplusia ni (cabbage loo ... | 1990 | 1366777 |
| genetic manipulation of bacillus thuringiensis insecticidal crystal protein genes in bacteria. | | 1991 | 1367416 |
| are b.t.k. plants really safe to eat? | | 1990 | 1369294 |
| design and use of synthetic oligonucleotide probes in the cloning of delta-endotoxin genes from bacillus thuringiensis. | a detailed protocol is described for the design and use of synthetic oligonucleotide probes for screening dna libraries from bacillus thuringiensis var. kurstaki (strain hd191) for copies of the gene (tox) encoding the insecticidal delta-endotoxin. two homologous tox genes were identified in this organism; one of these was located on a 75-kb plasmid and the other on a second large plasmid or the bacterial chromosome. a tox gene was isolated as a 6.5-kb hindiii fragment of b. thuringiensis plasmi ... | 1991 | 1369333 |
| nucleotide sequence of gene cryiiid encoding a novel coleopteran-active crystal protein from strain bti109p of bacillus thuringiensis subsp. kurstaki. | the nucleotide sequence of a novel insecticidal crystal protein(cry)-encoding gene from a bacillus thuringiensis serotype kurstaki isolate is described. the gene is related to the known coleopteran-active cryiii genes and encodes a cryiiid that is much more active against colorado potato beetle than other cryiii. | 1992 | 1544571 |
| biopesticides and resistance. | | 1992 | 1546283 |
| identification of an insecticidal crystal protein from bacillus thuringiensis dsir517 with significant sequence differences from previously described toxins. | the nucleotide (nt) sequence of a dna segment containing the majority of a gene cloned from bacillus thuringiensis dsir517 encoding a 130 kda insecticidal crystal protein has been determined. sequence analysis reveals an open reading frame (orf) of 3453 nt. the atg initiation codon, which is preceded by a potential ribosome-binding site sequence, was confirmed by n-terminal amino acid sequencing. the orf extends beyond the 3' terminus of the cloned fragment; however, the high degree of homology ... | 1992 | 1556556 |
| overproduction, purification and characterization of m.hinfi methyltransferase and its deletion mutant. | we have used the polymerase chain reaction to alter transcriptional and translational signals surrounding the hinfim gene [encoding m.hinfi methyltransferase (mtase)] so as to achieve overexpression in escherichia coli. the pcr-generated hinfim gene was subcloned in a high-expression vector under control of the hybrid trp-lac promoter. in addition, the positive retroregulator stem-loop sequence derived from the crystal protein-encoding gene of bacillus thuringiensis was inserted downstream from ... | 1992 | 1563635 |
| expression of the mosquitocidal toxins of bacillus sphaericus and bacillus thuringiensis subsp. israelensis by recombinant caulobacter crescentus, a vehicle for biological control of aquatic insect larvae. | in the quest for effective control of mosquitoes, attention has turned increasingly to strains of the bacteria bacillus sphaericus and bacillus thuringiensis subsp. israelensis, which produce potent toxins with specific mosquitocidal activities. however, sedimentation of the bacterial spores limits the duration of effective control after field application of these bacilli. we describe here the cloning of genes encoding the 51.4- and 41.9-kda toxins from b. sphaericus 2297, the 100-kda toxin from ... | 1992 | 1575492 |
| expansion of insecticidal host range of bacillus thuringiensis by in vivo genetic recombination. | we describe a novel approach for the insertion of an insecticidal toxin gene into a resident plasmid in bacillus thuringiensis (bt). a gene encoding a coleopteran-specific toxin was cloned within a fragment of is232 and inserted into a plasmid thermosensitive for replication in bt. the plasmid was used to transform a bt strain toxic to lepidoptera, and the transformants were then selected at non-permissive temperature for clones in which the vector had integrated into a copy of is232 present on ... | 1992 | 1369394 |
| hyperthermic potentiation of bleomycin cytotoxicity in the presence of bacillus thuringiensis subsp. israelenis delta-endotoxin. | we previously reported that a 25-kda bacillus thuringiensis subsp. israelensis (bti) delta-endotoxin potentiated the antitumor activity of bleomycin (blm) in both in vitro and in vivo systems. we report here a characteristic hyperthermic synergy toward the cytocidal activity of blm in the presence of bti endotoxin in cultured l1210 cells. cytocidal gain, i.e., the ratio of the ic50 of blm in the absence versus the presence of bti delta-endotoxin, reached ca. 20 at 40 degrees c, suggesting that a ... | 1992 | 1380225 |
| identification and characterization of a novel bacillus thuringiensis delta-endotoxin entomocidal to coleopteran and lepidopteran larvae. | a new class of bacillus thuringiensis delta-endotoxins, or insecticidal control proteins (icps), is defined by an apparently cryptic protein with a unique primary structure and novel entomocidal specificity for certain coleopteran and lepidopteran species. the discovery of a new group of icps will extend the use of this natural insecticide in integrated pest-management systems. | 1992 | 1588820 |
| vasopressin stimulation of vanadate-sensitive na+ transport by liver plasma membrane vesicles. evidence for regulation via phospholipase c and protein kinase c activities. | the rate of vanadate-sensitive 22na+ uptake by isolated liver membrane vesicles, reflecting transport by na+/k(+)-atpase, was measured to study the role played by phospholipase c and protein kinase c in the regulation of this process by vasopressin. na+ uptake was enhanced 2-3-fold by 100 nm [arg8]vasopressin and the hormone effect was mimicked by 0.1 microm inositol 1,4,5-trisphosphate as well as by 1.0 microm myo-inositol. the stimulation by vasopressin was potentiated by phosphatidylinositol- ... | 1992 | 1390861 |
| [inversion polymorphism in the malaria mosquito anopheles messeae. xi. the group effect of larval infection with bacillus thuringiensis subsp. israeliensis bacteria]. | genetic consequences of the group and individual infections of anopheles messeae larvae with bacteria bacillus thuringiensis subsp. israelensis (bti) were examined. the group effect of infections was manifested by increase in mortality and the speed-up of selection of chromosomal inversions resistant to bti. connection between the group and individual selections during the process of populations' adaptation is under discussion. | 1992 | 1427060 |
| efficacy of bacillus thuringiensis var. israelensis against larvae of the southern buffalo gnat, cnephia pecuarum (diptera: simuliidae), and the influence of water temperature. | susceptibility of southern buffalo gnat larvae to bacillus thuringiensis var. israelensis (b.t.i.) was studied during 1986-88. tests were conducted using vectobac 12as in a mini-gutter aquatic bioassay system. mini-gutter tests using a 4.5 ppm b.t.i. concentration and a 10 min exposure period confirmed a positive correlation between water temperature and b.t.i. effectiveness. significantly lower larval mortality occurred as water temperature decreased below 9 degrees c, indicating that proper ti ... | 1992 | 1431853 |
| properties of a 72-kilodalton mosquitocidal protein from bacillus thuringiensis subsp. morrisoni pg-14 expressed in b. thuringiensis subsp. kurstaki by using the shuttle vector pht3101. | the mosquitocidal properties of bacillus thuringiensis subsp. israelensis and b. thuringiensis subsp. morrisoni pg-14 are attributable to protein inclusions grouped together within a parasporal body. in both of these strains, the mosquitocidal activity resides in proteins with molecular masses of 27, 72, 128, and 135 kda. in an attempt to determine the toxicity of each protein, the shuttle vector pht3101 was used to express the cryivd gene (encoding the 72-kda cryivd protein) from b. thuringiens ... | 1992 | 1610175 |
| insecticidal properties of a crystal protein gene product isolated from bacillus thuringiensis subsp. kenyae. | a protoxin gene, localized to a high-molecular-weight plasmid from bacillus thuringiensis subsp. kenyae, was cloned on a 19-kb bamhi dna fragment into escherichia coli. characterization of the gene revealed it to be a member of the cryie toxin subclass which has been reported to be as toxic as the cryic subclass to larvae from spodoptera exigua in assays with crude e. coli extracts. to directly test the purified recombinant gene product, the gene was subcloned as a 4.8-kb fragment into an expres ... | 1992 | 1610185 |
| fate of bacillus sphaericus and bacillus thuringiensis serovar israelensis in the aquatic environment. | bacillus sphaericus spores were suspended in bottles of filtered (0.45 microns) freshwater and seawater under various conditions of temperature, ph and salinity. heat resistant culturable counts (spores) slowly decreased with time. spores suspended in dialysis bags submerged in a freshwater pond or in flowing seawater underwent a more rapid drop in heat resistant spore counts than did spores held in bottles. thus, laboratory studies may overestimate spore longevity in the environment. spore sett ... | 1992 | 1431856 |
| toxicity of bacillus thuringiensis against damalinia ovis (phthiraptera:mallophaga). | | 1992 | 1619297 |
| cloning and expression of the cryivd gene of bacillus thuringiensis subsp. israelensis in the cyanobacterium agmenellum quadruplicatum pr-6 and its resulting larvicidal activity. | a mosquitocidal cyanobacterium has been developed by introducing the mosquito-toxic cryivd gene from bacillus thuringiensis subsp. israelensis into the unicellular cyanobacterium agmenellum quadruplicatum pr-6 (synechococcus sp. strain pcc 7002). the cryivd gene was introduced into the cyanobacterium on a derivative of the pr-6 expression vector paqe19 delta sal in which the cryivd gene was translationally fused to the initial coding sequence of the highly expressed pr-6 cpcb gene. coomassie blu ... | 1992 | 1622235 |
| reduction of mortality rates of bacillus thuringiensis var. israelensis aqueous suspensions due to freezing and thawing. | when studying the behavior (carry, dispersion, persistence) of bacillus thuringiensis var. israelensis (b.t.i.) formulations used in the treatment of rivers or streams for black fly control, a large number of samples containing small quantities of b.t.i. are required for proper analysis. freezing is a useful procedure to prevent enzymatic alteration or bacterial growth in samples before bioassays are to be performed. using aedes atropalpus neonate larvae, we studied the effect of freezing and th ... | 1992 | 1431857 |
| an episode of resistance to permethrin in larvae of simulium squamosum (diptera: simuliidae) from cameroon, after 3 1/2 years of control. | because of the biting nuisance from females of simulium squamosum, a 30 km section of the sanaga river (cameroon) was treated since 1987 with permethrin for the control of larval populations. in 1990, resistance to permethrin occurred in a small proportion of the larvae, with a resulting 2-4x increase of the lc95 for dead larvae (moribund larvae considered as live). in 1991, after a 6-month interruption of the treatments, susceptibility to permethrin returned to the initial level, and was simila ... | 1992 | 1431861 |
| identification of phosphatidylinositol-specific phospholipase c activity in listeria monocytogenes: a novel type of virulence factor? | a phospholipase c which cleaves phosphatidylinositol and glycosylphosphatidylinositol (gpi) anchors was identified in listeria monocytogenes. this 36 kda protein is encoded by the gene plca, and is homologous to the bacillus cereus, bacillus thuringiensis and eukaryotic phosphatidylinositol-specific phospholipases c (pi-plc). expression of the plca gene in escherichia coli correlates with the appearance of pi-plc activity in the cells. in listeria monocytogenes, the activity is secreted to the c ... | 1991 | 1645839 |
| phosphatidylinositol-specific phospholipases c from bacillus cereus and bacillus thuringiensis. | | 1991 | 1646937 |
| is231a from bacillus thuringiensis is functional in escherichia coli: transposition and insertion specificity. | a kanamycin resistance gene was introduced within the insertion sequence is231a from bacillus thuringiensis, and transposition of the element was demonstrated in escherichia coli. dna sequencing at the target sites showed that is231a transposition results in direct repeats of variable lengths (10, 11, and 12 bp). these target sequences resemble the terminal inverted repeats of the transposon tn4430, which are the preferred natural insertion sites of is231 in b. thuringiensis. | 1991 | 1648561 |
| sequence of an operon containing a novel delta-endotoxin gene from bacillus thuringiensis. | an insect larval toxin designated cryii is produced by several subspecies of bacillus thuringiensis and differs from the other major delta-endotoxins in these bacteria in its size, toxicity profile and presence as part of an operon with three open reading frames (orf). such an operon from a novel b. thuringiensis isolate has been cloned and differs from one previously characterized in the following ways: (a) the size and number of amino acid repeats in one of the orfs; (b) the smaller size of th ... | 1991 | 1651878 |
| amphiphilic forms of butyrylcholinesterase in mucosal cells of rat intestine. | the properties of a cholinesterase from mucosal cells of rat intestine have been characterized. the enzyme was identified as butyrylcholinesterase because it was more sensitive to iso-ompa (ic50 = 1.0 x 10(-6) m) than to bw284c51 (ic50 = 5.5 x 10(-5) m) and was not inhibited by substrate excess. it displayed a higher affinity for acetylthiocholine than for butyrylthiocholine. a major molecular form was observed sedimenting at 5.9 s. two other minor molecular forms were identified as a hydrophili ... | 1992 | 1420201 |
| cloning and analysis of delta-endotoxin genes from bacillus thuringiensis subsp. alesti. | bacillus thuringiensis subsp. alesti produced only cryia(b)-type protoxins, and three cryia(b) genes were cloned. one was cryptic because of an alteration near the 5' end, and the other two were very similar to each other. the protoxin encoded by one of the latter genes differed from other cryia(b) protoxins in its greater stability and relative toxicity for two members of the order lepidoptera. | 1991 | 1655719 |
| the study on phosphatidylinositol-specific phospholipase c from bacillus thuringiensis: synthesis of homogeneous substrates, substrate specificity and other properties. | the properties of phosphatidylinositol-specific phospholipase c (pi-plc) from bacillus thuringiensis were studied in detail. the enzyme was extremely thermostable in 0.1% bovine serum albumin and retained 73% of its activity at 100 degrees c for 10 min, while it was labile in the absence of albumin. the enzymatic activity was inhibited by hgcl2 or p-chloromercuriphenylsulfonic acid and restored by dithiothreitol. the kinetic parameters (km and vmax) of pi-plc were determined for the mixed micell ... | 1992 | 1423768 |
| isolation and sequence of a 2-kbp miniplasmid from bacillus thuringiensis var. kurstaki hd-3a3b: relationship with miniplasmids of other b. thuringiensis strains. | the miniplasmid profiles of 18 bacillus thuringiensis strains belonging to 8 different serotypes were determined using an alkaline hydrolysis method for isolation of low molecular mass plasmids. nearly all the strains contained covalently closed circular (ccc) dna species ranging from 2 to 5 species per strain and from 1.5 to 10.5 kbp in size (values corresponding to ccc forms). a 2-kbp plasmid from b. thuringiensis var. kurstaki hd-3a3b futura strain was used in southern hybridization experimen ... | 1992 | 1426990 |
| a novel bioassay system for evaluating the toxicity of bacillus thuringiensis israelensis against mosquito larvae. | a bioassay system employing acutely toxic concentrations of a spore-crystal mixture of bacillus thuringiensis subspecies israelensis against fourth instar larvae of aedes aegypti (l.) is described. individual larvae are separately exposed to toxin in glass-lined miniature wells or scintillation vials. this method is free from the deaths due to predation among larvae. such larval deaths are commonly encountered in bioassay groups of 25 larvae as currently specified in the world health organizatio ... | 1992 | 1607671 |
| [a trial of the possible joint use of mermithids and bacterial preparations for the control of mosquito larvae]. | the action of bacterial insecticides based on bacillus thuringiensis h-14 and b. sphaericus in a dose of 0.005-2 mg/l on the mermithids romanomermis iyengari, r. culicivorax and r. jingdeensis was studied. it was shown that though bacterial agents suppressed mermithid preparasite larvae density about 30-40%, the survivors might invade 100% of mosquito larvae. the viability and fertility of adult mermithids did not change under the influence of bactoculicide in doses 5-50 times higher than those ... | 1992 | 1435554 |
| properties of bacillus thuringiensis and its intracellular crystal proteins. | | 1992 | 1504588 |
| construction of cloning vectors for bacillus thuringiensis. | the replication region of the bacillus thuringiensis plasmid, pht1030, was treated with hydroxylamine. various copy-number mutants were selected and subsequently used to construct shuttle vectors with multiple cloning sites. these recombinant plasmids are very stable and allowed the cloning of a delta-endotoxin-encoding gene in b. thuringiensis. comparison between gene expression level and vector copy-number indicated that a plateau in delta-endotoxin production is reached with a copy-number of ... | 1991 | 1662180 |
| novel bacillus thuringiensis insecticidal crystal protein with a silent activity against coleopteran larvae. | a novel bacillus thuringiensis crystal protein with a silent activity against the colorado potato beetle is described. the crystal proteins are produced as bipyramidal crystals. these crystals contain a protein of 129 kda with a trypsin-resistant core fragment of 72 kda. neither a spore-crystal mixture nor in vitro-solubilized crystals are toxic to any of several lepidoptera and coleoptera species tested. in contrast, a trypsin-treated solution containing the 72-kda tryptic core fragment of the ... | 1992 | 1514800 |
| insect resistance of transgenic tobacco plants expressing delta-endotoxin gene of bacillus thuringiensis. | the initiative b.thuringiensis delta-endotoxin (bt toxin) gene clones th12 and th48 contain two different classes of homologous genes, the 5.3 kb class and 6.6 kb class, respectively. bt toxin genes of both classes, modified at the 5'-end and truncated at the 3'-end, can still be expressed to produce the insecticidal, truncated toxin proteins in e. coli. the modified bt toxin genes were inserted into the plant binary expression vector pbin 437 (a derivative plasmid of pbin 19) and were transferr ... | 1991 | 1663400 |
| the c-terminal domain of the toxic fragment of a bacillus thuringiensis crystal protein determines receptor binding. | the insecticidal crystal proteins of bacillus thuringiensis show a high degree of specificity. in vitro binding studies with several crystal proteins demonstrated a correlation between toxicity and binding to receptors of larval midgut epithelial cells. in order to study the domain-function relationships of the toxic fragment, hybrid crystal proteins based on cryia(b) and cryic were constructed. two out of 11 hybrid proteins constructed exhibited insecticidal activity. both dispalyed an insectic ... | 1991 | 1664021 |
| stability of the delta-endotoxin gene from bacillus thuringiensis subsp. kurstaki in a recombinant strain of clavibacter xyli subsp. cynodontis. | deletion of chromosomally inserted gene sequences from clavibacter xyli subsp. cynodontis, a xylem-inhabiting endophyte, was studied in vitro and in planta. we found that nonreplicating plasmid pcg610, which conferred resistance to kanamycin and tetracycline and contained segments of c. xyli subsp. cynodontis genomic dna, integrated into a homologous sequence in the bacterial chromosome. in addition, pcg610 contains two copies of the gene encoding the cryia(c) insecticidal protein of bacillus th ... | 1991 | 1664710 |
| arabidopsis thaliana small subunit leader and transit peptide enhance the expression of bacillus thuringiensis proteins in transgenic plants. | the expression of the modified gene for a truncated form of the cryia(c) gene, encoding the insecticidal portion of the lepidopteran-active cryia(c) protein from bacillus thuringiensis var. kurstaki (b.t.k.) hd73, under control of the arabidopsis thaliana ribulose-1,5-bisphosphate carboxylase (rubisco) small subunit ats1a promoter with and without its associated transit peptide was analyzed in transgenic tobacco plants. examination of leaf tissue revealed that the ats1a promoter with its transit ... | 1992 | 1515613 |
| fed-batch fermentation studies with bacillus thuringiensis h-14 synthesising endotoxin. | cell yield and toxicity of b. thuringiensis h-14 was improved markedly by adopting a simple fed-batch fermentation technique based on controlling glucose concentration. maintenance of steady glucose concentration (0.3-0.5%) in the culture medium was achieved by the continuous addition of concentrated glucose solution. addition of glucose at 3 g/hr/l of culture starting from 3rd hr till 16th hr of fermentation was found to yield cell densities of 80 g/l (wet weight) which represented a nearly 3-f ... | 1991 | 1667779 |
| high-level expression in escherichia coli and rapid purification of phosphatidylinositol-specific phospholipase c from bacillus cereus and bacillus thuringiensis. | the construction of four vectors for high-level expression in escherichia coli of the phosphatidylinositol-specific phospholipase c from bacillus cereus or bacillus thuringiensis is described. in all constructs the coding sequence for the mature phospholipase is precisely fused to the e. coli heat-stable enterotoxin ii signal sequence for targeting of the protein to the periplasm. in one set of plasmids expression of the b. cereus or b. thuringiensis enzyme is under control of the e. coli alkali ... | 1991 | 1668269 |
| delivery of an accessory signal for cell activation by exogenous phosphatidylinositol-specific phospholipase c. | digestion of phosphatidylinositol (pi) or glycosylphosphatidylinositol (gpi) anchors of membrane proteins on the external cell surface with exogenous pi-specific phospholipase c (piplc) from bacillus thuringiensis was shown to transmit a signal into the thymocyte to modulate the tcr/cd3 complex-induced signal delivery for cell activation. this was demonstrated for very early protein tyrosine phosphorylation, early c-fos transcription and late dna synthesis. for this effect preincubation of the c ... | 1992 | 1535048 |
| deletion by in vivo recombination shows that the 28-kilodalton cytolytic polypeptide from bacillus thuringiensis subsp. israelensis is not essential for mosquitocidal activity. | the cyta gene encoding the 28-kda polypeptide of bacillus thuringiensis subsp. israelensis crystals was disrupted in the 72-mda resident plasmid by in vivo recombination, thus indicating that homologous recombination occurs in b. thuringiensis. the absence of the 28-kda protein in b. thuringiensis did not affect the crystallization of the other toxic components of the parasporal body (68-, 125-, and 135-kda polypeptides). the absence of the 28-kda protein abolished the hemolytic activity of b. t ... | 1991 | 1675212 |
| translation enhancing properties of the 5'-leader of potato virus x genomic rna. | the double-stranded dna copy corresponding to the 5'-nontranslated alpha beta-leader of potato virus x (pvx) genomic rna (positions -3 to-85 according to aug initiator) was chemically synthesized and fused to the transcription plasmids containing three different reporter genes: neomycinphosphotransferase type ii (npt ii) gene, bacillus thuringiensis coleopteran-specific toxic protein gene and beta-glucuronidase (gus) gene. expression of the reporter genes in vitro and in plant protoplasts (in th ... | 1992 | 1537401 |
| membrane-bound aminopeptidase p from bovine lung. its purification, properties, and degradation of bradykinin. | the membrane-bound form of aminopeptidase p (aminoacylprolyl-peptide hydrolase) (ec 3.4.11.9) was purified to apparent homogeneity from bovine lung microsomes. the enzyme was solubilized using phosphatidylinositol-specific phospholipase c (bacillus thuringiensis), indicating that bovine lung amino-peptidase p is attached to membranes via a glycosylphosphatidylinositol anchor. the enzyme was purified 1900-fold with a yield of 25% by chromatography on decyl-agarose, omega-aminodecyl-agarose, a sec ... | 1992 | 1537867 |
| the insecticidal crystal protein cryia(c) from bacillus thuringiensis is highly toxic for heliothis armigera. | | 1992 | 1541846 |
| bacillus thuringiensis crystal protein: effect of chemical modification of the cysteine and lysine residues. | the 16 cysteine residues of reduced protoxin from bacillus thuringiensis subsp. kurstaki hd-73 can be quantitatively reacted with: (a) iodoacetic acid, to give carboxymethyl protoxin; (b) iodoacetamide, giving carbaminomethyl protoxin and (c) n-(beta-iodoethyl)trifluoroacetamide to give aminoethyl protoxin. the carboxymethyl derivative was found to be significantly more soluble at neutral ph values where both the native protoxin and the carbaminomethyl derivative exhibit low solubilities. at the ... | 1992 | 1541850 |
| isolation of mosquito-toxic bacteria from mosquito-breeding sites in kenya. | a large number of source materials were collected for isolating entomopathogenic bacteria from larval mosquito habitats in kirinyaga district, kenya. mosquito-toxic bacteria were included among the numerous types of microorganisms isolated from the habitats. the pathogenic isolates shared common structural characteristics; they were gram-positive, spore-forming bacilli that produced parasporal inclusions conferring broad-spectrum larvicidal activity against anopheles, culex and aedes mosquitoes. ... | 1992 | 1583497 |
| [the optimization of a method for determining the insecticidal activity of bacterial preparations vis-à-vis mosquito larvae]. | | 1992 | 1435585 |
| extra cellular hydrolytic enzyme secretion in bacillus thuringiensis h14 & b. sphaericus & their significance in media design. | level of extracellular proteolytic and amylolytic enzyme production was determined to assess the ability of these strains in utilizing complex carbon and nitrogen sources. protease secretion reached maximum at around 12th h of growth in case of all the three b. thuringiensis strains and declined sharply thereafter. in b. sphaericus strains the protease level gradually increased and reached maximum at around 24th h of growth. amylase activity was not detectable in the culture supernatants of b. s ... | 1990 | 1693135 |
| [antigenic structure of endotoxins from bacillus thuringiensis]. | the proteins of parasporal crystals of 9 strains of entomopathogenic bacteria of the bacillus thuringiensis group of different h-serotypes were studied by different methods. electrophoresis showed that crystals from the bacteria of 1, 3, 4, 5, 8, and 10 serotypes contained 1-2 proteins with a molecular weight of 130-145 kd and an additional fraction with a molecular weight of 55-120 kd. double-radial immunodiffusion revealed that the crystals of all the serotypes studied are immunologically rela ... | 1990 | 1693428 |
| delta-endotoxins form cation-selective channels in planar lipid bilayers. | delta-endotoxins cryia(c) and cryiiia, two members of a large family of toxic proteins from bacillus thuringiensis, were each allowed to interact with planar lipid bilayers and were analyzed for their ability to form ion-conducting channels. both of these toxins made clearly resolved channels in the membranes and exhibited several conductance states, which ranged from 200 ps to about 4000 ps (in 300 mm kcl). the channels formed by both toxins were highly cation-selective, but not ideally so. the ... | 1990 | 1694077 |
| characterization of two genes encoding bacillus thuringiensis insecticidal crystal proteins toxic to coleoptera species. | bacillus thuringiensis eg2838 and eg4961 are highly toxic to colorado potato beetle larvae, and only strain eg4961 is toxic to southern corn rootworm larvae. to investigate the cause of the different insecticidal activities of eg2838 and eg4961, cryiii-type genes toxic to coleopterans were cloned from each strain. the cryiiib gene, cloned as part of an 8.0-kb ecori fragment of eg2838 dna, encoded a crystal protein (cryiiib) of 74,237 da. the cryiiib2 gene, cloned as part of an 8.3-kb psti-asp718 ... | 1992 | 1476436 |
| increase in the resistance to the bacillus thuringiensis supernatant effect in a drosophila melanogaster wild type oregon r line. | we report here the genetical and x chromosome rdna molecular study of two drosophila melanogaster oregon r lines. these lines differ extensively in the degree of resistance of the females both to the lethal effect of an increased temperature and to that of bacillus thuringiensis beta-exotoxin, which is an inhibitor of the nucleolar rna polymerase. the 3b line, whose females are resistant, came from an oregon r population subjected over several generations to increased temperature, 28 degrees c o ... | 1992 | 1478886 |
| [extracellular alkaline ribonuclease of bacillus thuringiensis var. subtoxicus]. | intraspecific selection of bacillus thuringiensis strains producing extracellular alkaline ribonucleases was carried out. subtoxicus subspecies with increased expression of the enzyme was detected. a method was developed to isolate preparative amounts of homogeneous extracellular rnase of b. thuringiensis var. subtoxicus. the physico-chemical and catalytic properties of the enzyme was studied and compared with extracellular rnases of others bacillus species. the conclusion about the structural a ... | 1992 | 1491677 |
| early response of cultured lepidopteran cells to exposure to delta-endotoxin from bacillus thuringiensis: involvement of calcium and anionic channels. | the role of ion channels in the initial steps following exposure of sf-9 lepidopteran insect cells in culture to the delta-endotoxin cryic from the insecticidal bacterium bacillus thuringiensis was investigated using single ionic channel measurements and microspectrofluorescence of the calcium-sensitive probe fura-2. it was found that: (1) the toxin triggers an immediate rise in intracellular calcium; (2) the surge is due to calcium entering the cells via calcium channels; (3) the toxin recruits ... | 1991 | 1711900 |
| comparative analysis of bacillus anthracis, bacillus cereus, and related species on the basis of reverse transcriptase sequencing of 16s rrna. | the primary structures of the 16s rrnas of bacillus anthracis, bacillus cereus, bacillus mycoides, and bacillus thuringiensis were determined by using the reverse transcription-dideoxy sequencing method. all of the strains exhibited very high levels of sequence similarity (greater than 99%) that were consistent with the close relationships shown by previous dna hybridization studies. the sequences of b. anthracis sterne and b. cereus emetic strain nctc 11143 were found to be identical for a cont ... | 1991 | 1715736 |
| inhibition of potassium-gradient-driven phenylalanine uptake in larval lymantria dispar midgut by two bacillus thuringiensis delta-endotoxins correlates with the activity of the toxins as gypsy moth larvicides. | | 1991 | 1661774 |
| lethal and sublethal effects of bacillus thuringiensis var. kurstaki on aquatic insects in laboratory bioassays and outdoor stream channels. | | 1992 | 1611248 |
| plasma-membrane-intercalated heparan sulphate proteoglycans in an osteogenic cell line (umr 106-01 bsp). | the heparan sulphate (hs) proteoglycans associated with the cell layer of a rat osteosarcoma cell line [umr 106-01 (bsp)] were compared with similar cell-associated proteoglycans from other cells, and their interaction with the plasma membrane was studied. hs proteoglycans were metabolically labelled by incubation of cell cultures with [3h]glucosamine or [3h]leucine and [35s]sulphate. hs proteoglycan core protein preparation generated by heparitinase digestion of the major species from umr 106-0 ... | 1992 | 1637308 |
| molecular characterization of two novel crystal protein genes from bacillus thuringiensis subsp. thompsoni. | two genes encoding the predominant polypeptides of bacillus thuringiensis subsp. thompsoni cuboidal crystals were cloned in escherichia coli and sequenced. the polypeptides have electrophoretic mobilities of 40 and 34 kda, with the deduced amino acid sequences predicting molecular masses of 35,384 and 37,505 da, respectively. no statistically significant similarities were detected between the 40- or 34-kda crystal protein and any other characterized b. thuringiensis crystal protein, nor were the ... | 1992 | 1729243 |
| synthesis and toxicity of full-length and truncated bacterial cryivd mosquitocidal proteins expressed in lepidopteran cells using a baculovirus vector. | full-length (72k) and truncated (61k) cryivd mosquitocidal proteins of bacillus thuringiensis (bt) were expressed in spodoptera frugiperda cells and larvae of trichoplusia ni using a baculovirus vector to investigate the role of cryivd peptides in toxicity as well as to evaluate further the baculovirus/lepidopteran system for expressing bt proteins. the cryivd genes were inserted into the autographa californica multinucleocapsid nuclear polyhedrosis virus (acmnpv) under control of the polyhedrin ... | 1992 | 1730944 |
| spba locus ensures the segregational stability of pth1030, a novel type of gram-positive replicon. | the replication region of the plasmid pht1030 of bacillus thuringiensis was previously mapped to a 2.9 kb dna fragment. the dna sequence was analysed and it was shown that the minimal replicon resides within a 1 kb fragment of dna carrying no potential protein coding sequence. moreover, no production of single-stranded dna intermediates was detected in the plasmid-containing cells. pht1030 therefore belongs to a class of replicons not previously described in gram-positive bacteria. examination o ... | 1992 | 1738313 |
| [mobilization transfer of the pub110 plasmid between gram-positive bacteria]. | the three factor crosses between the donor strain bacillus subtilis 168 harbouring the plasmid pub102-4, bacillus thuringiensis strain carrying the mobilizing plasmid pam beta 1 and recipient strain lactobacillus fermenti were conducted in order to elaborate the optimal conditions of the plasmid pub102-4 mobilization for transfer into gram-positive microorganisms and to elucidate the possible expression of endogluconase genes in a lactobacillus strain. the lactobacillus fermenti transconjugants ... | 1991 | 1745269 |
| biopesticides and resistance. | | 1992 | 1637378 |
| a study of human erythrocyte acetylcholinesterase inhibition by chlorpromazine. | membrane-bound acetylcholinesterase (ache) from the human erythrocyte is inhibited by chlorpromazine (cpz) in a concentration range within this amphiphilic drug has been demonstrated to interact with erythrocyte membranes, causing a large spectrum of physical and structural effects; membrane solubilization with 0.5% triton x-100 results in a complete loss of cpz inhibitory potency. although these observations might suggest a role of membrane lipid environment in mediating human erythrocyte ache ... | 1991 | 1654884 |
| toxicity of bacillus thuringiensis to laboratory populations of the olive fruit fly (dacus oleae). | a survey of bacillus thuringiensis recovered from the environments of olive groves in greece was carried out. of 80 soil samples, 24 were found to contain b. thuringiensis with parasporal crystal inclusions; these were tested for toxicity against the olive fruit fly (dacus oleae). mortality levels of larvae caused by the different isolates varied from 7 to 87%. higher levels of mortality were observed if a mixture of relatively pure crystals and spores was used compared with the mortality result ... | 1991 | 1768100 |
| 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 |
| 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 |
| identification and characterization of heliothis virescens midgut membrane proteins binding bacillus thuringiensis delta-endotoxins. | to investigate the specificity of bacillus thuringiensis var. kurstaki strain hd1 insecticidal crystal proteins (icp), we used membrane preparations obtained from the midgut of heliothis virescens larvae to perform separate ligand-blot experiments with the three activated cryia toxins. the cryia(a) and the cryia(b) toxins bind the same 170-kda protein, but most likely at two different binding sites. the cryia(c) toxin binds two proteins of molecular masses 140 kda and 120 kda. we also demonstrat ... | 1991 | 1662137 |
| differential inhibition by bacillus thuringiensis delta endotoxin of leucine and aspartic acid uptake into bbmv from midgut of manduca sexta. | pre-incubation of brush border membrane vesicles (bbmv) isolated from the midgut of manduca sexta with activated bacillus thuringiensis delta endotoxin for a short period resulted in differential inhibition of k(+)-dependent transport of leucine relative to the effect on k(+)-dependent transport of aspartic acid. the difference in i1/2 (5 fold greater for aspartic acid than for leucine) is interpreted as the result of enhanced binding of the b. thuringiensis delta endotoxin to the leucine transp ... | 1991 | 1662492 |
| 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 |
| [search for producers of restriction endonucleases with a given specificity]. | six site-specific restriction endonucleases were isolated from bacillus thuringiensis strains chosen of 58 strains ought purposefully for production of restriction enzymes. all six strains produce isoschisomers of sau3a. | 1991 | 1667028 |
| [bacillus thuringiensis: biological characteristics and production perspectives]. | in this paper the potential activity of bacillus thuringiensis as insecticide is reviewed. it is presented recent knowledges of its metabolism, production system and the rinetic constants already reported finally the possibilities for production in batches or continuous culture is discussed in order to improve the productivity and economical aspects. | 1991 | 1670264 |
| 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 |