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PubMedDate not supplied

[Optimization of a synthetic nutrient medium for culturing Bacillus thuringiensis].

The requirement of Bacillus thuringiensis subsp. galleriae 69/6 for amino acids and vitamins was studied. The composition of a synthetic nutrient medium was optimized. Alanine and nicotinic acid were found to be necessary for growth while other amino acids (aspartic and glutamic acids, histidine, threonine) were not indispensable although they increased the population density (yield). A deficiency as well as an excess of individual amino acids (threonine and glutamic acid) inhibited growth and decreased the yield of biomass. Elevated concentrations of aspartic and glutamic acids inhibited the formation of spores and crystals. As was demonstrated using the method of mathematical planning of an experiment, the synthetic medium contained optimal concentrations of nicotinic and amino acids and was suitable for the growth of B. thuringiensis strains as well as for the formation of spores and crystals by them.

Amino Acids↗
PubMedDate not supplied

[Effect of gramicidin D on the exoprotease activity of Bacillus thuringiensis].

A treatment of Bacillus thuringiensis cells with gramicidine D in the medium containing the yeast and polysaccharides increases the lag-phase up to 12 h without a change of the rate during the logarithmic phase of the culture growth. The exoprotease activity of cells treated with gramicidine reaches a maximum value 4 h earlier in comparison with the control culture, and the activity level is increased 2-fold. At a concentration increasing the exoprotease activity, gramicidine was found to induce the permeability of Bac. thuringiensis membranes for potassium ions. An additional introduction of 250 mM KCl or NaCl into the medium inhibits only the exoprotease activity of cells treated with gramicidine. It is assumed that the ability of gramicidine to increase the exoprotease activity of Bac. thuringiensis may be due to a change in the intrabacterial ionic composition.

Bacillus thuringiensis↗
PubMed1993

Analysis of common antigen of flagella in Bacillus cereus and Bacillus thuringiensis.

Flagellar antigen of Bacillus cereus H.1 was purified and tested for serodiagnostic antigen by ELISA. The antibody against the flagellar antigen of B. cereus H.1 reacted not only with the homologous specific antigen but also reacted with the flagellar antigens of 23 strains of B. cereus. This common flagellar antigen of B. cereus was found to be due to 61-kDa protein by SDS-PAGE and immunoblot assay. Monoclonal antibody H15A5 against common antigenic epitope of B. cereus also reacted with flagellar antigens of 21 strains of Bacillus thuringiensis by ELISA. This monoclonal antibody reacted with the 61-kDa protein of the flagella of B. cereus H.1 and H.2 and B. thuringiensis Kurstaki HD1, Alesti and Aizawai juroi by immunoblot analysis. These results indicated that the common antigenic epitope of the 61-kDa protein existed in the flagella both of B. cereus and B. thuringiensis.

Antibodies, Bacterial↗
PubMed2004

Fate of Bacillus thuringiensis strains in different insect larvae.

In favorable conditions Bacillus thuringiensis spores germinate and vegetative cells multiply, whereas in unfavorable conditions Bacillus thuringiensis sporulates and produces insecticidal crystal proteins. The development of B. thuringiensis strains was investigated in the larvae of insects belonging to the orders Lepidoptera and Diptera. Bacillus thuringiensis strains able to kill the insects did not always multiply in cadavers. Strains with no specificity to kill the insect sometimes multiplied when the insects were killed mechanically. These results indicate that some insect larvae represent an environment that favors the germination of B. thuringiensis spores and the multiplication of vegetative cells; however, there was no correlation between the toxin specificity and the specificity of the host.

Animals↗
PubMed1984

[Bacteriocinogenic plasmids of Bacillus thuringiensis].

When strains of Bacillus thuringiensis v. morrisoni or v. darmstadiensis were plated on solid medium, the appearance of oligosporogenic (Ospo) mutants and bacteriocin non-producing clones (Thc-) was observed. The comparative analysis of the plasmid content of original and mutant strains revealed that the appearance of Ospo and Thc- phenotypes correlated with the loss of certain plasmids.

Bacillus thuringiensis↗
PubMed1976

[The effect of repeated amputations on planarian regeneration in the presence of the heat-stable toxin from Bacillus thuringiensis].

The exotoxin of Bacillus thuringiensis, which is an inhibitor of RNA synthesis, inhibits Planarian regeneration. Planarians which have been cut twice at the same level are able to regenerate after the second section in the presence of the toxin. This indicates that the first amputation stimulates a synthesis of stable RNAs which thus are available for regeneration at the moment of the second section.

Animals↗
PubMedDate not supplied

[Bacteriocin-like factor in Bacillus thuringiensis].

The paper describes Bacillus thuringiensis var. galleriae strains possessing a bacteriocin-like factor (factor K) which inhibits the cultures of a number of serotypes of Bac. thuringiensis. The K+ cultures exhibit no antibacterial effect on other gram-positive and gram-negative microorganisms. The maximal level of factor K is found by the 8--9th hour of cultivation. No correlation has been established between the strucutred elements in the preparations of K+ cultures and the antibacterial activity. Apparently, factor K can be transferred to other strains.

Antibiosis↗
PubMed2000

A replication origin of Bacillus thuringiensis.

A replication origin of Bacillus thuringiensis (Bt) was found in a Bacillus thuringiensis-Escherichia coli shuttle vector of pHT3101. Deletion analysis showed that the replication origin was segregationally stable at suitable temperature for Bt growth. The fragment containing the replication origin was cloned in pUC18 and sequenced. It was 261 base pairs in length, located in the open reading frame 2 (ORF2) of BTSPB sequence. The 261-bp fragment was cloned in pBR322, creating an improved Bt-E. coli shuttle vector pBR261, which contained two resistance genes responsible for ampicillin and tetracycline. Our study showed that the replication origin structure could be recognized by replication protein of host cells.

Bacillus thuringiensis↗
PubMed2004

Molecular characterization of Bacillus thuringiensis strains from Argentina.

Bacillus thuringiensis INTA 7-3, INTA 51-3, INTA Mo9-5 and INTA Mo14-4 strains were obtained from Argentina and characterized by determination of serotype, toxicity, plasmid composition, insecticidal gene content ( cry and vip ) and the cloning of the single- vip3A gene of the INTA Mo9-5 strain. The serotype analysis identified the serovars tohokuensis and darmstadiensis for the INTA 51-3 and INTA Mo14-4 strains, respectively, whereas the INTA Mo9-5 strain was classified as "autoagglutinated". In contrast to the plasmid patterns of INTA 7-3, INTA 51-3 and INTA Mo9-5 (which were similar to B. thuringiensis HD-1 strain), strain INTA Mo14-4 showed a unique plasmid array. PCR analysis of the four strains revealed the presence of cry genes and vip3A genes. Interestingly, it was found that B. thuringiensis 4Q7 strain, which is a plasmid cured strain, contained vip3A genes indicating the presence of these insecticidal genes in the chromosome. Bioassays towards various lepidopteran species revealed that B. thuringiensis INTA Mo9-5 and INTA 7-3 strains were highly active. In particular, the mean LC(50) obtained against A. gemmatalis larvae with the INTA Mo9-5 and INTA 7-3 strains were 7 (5.7-8.6) and 6.7 (5.6-8.0) ppm, respectively. The INTA Mo14-4 strain was non-toxic and strain INTA 51-3 showed only a weak larvicidal activity.

Animals↗
PubMed1999

Detection of genetic polymorphism by RAPD-PCR among isolates of Bacillus thuringiensis.

Sixteen isolates of Bacillus thuringiensis recovered from different Jordanian habitats were compared using random amplification of polymorphic DNA (RAPD) to determine whether they could be differentiated at the molecular level. Total genomic DNA from each isolate and three reference strains were amplified using 10-mer primers. Electrophoretic analysis of the amplification products revealed the incidence of polymorphism among the isolates. Pair-wise comparisons of polymorphic products were used to construct a dendrogram applying the cluster analysis. Fifteen of the isolates were all in one major cluster which was divided into six small groups. Such analysis showed some regional variation among the isolates, but did not indicate a clearly defined habitat locational pattern of the DNA polymorphism.

Bacillus thuringiensis↗
PubMed1995

Cloning and characterization of a Bacillus thuringiensis homolog of the spoIIID gene from Bacillus subtilis.

The SpoIIID protein of Bacillus subtilis (Bs) is a small DNA-binding protein that is essential for gene expression of the mother cell compartment during sporulation. We have cloned a DNA fragment from Bacillus thuringiensis (Bt) that showed a specific hybridization with the Bs spoIIID gene. Sequence analysis found an open reading frame encoding 90 amino acids (aa), which are 89% identical to the deduced aa sequence of Bs spoIIID. Upstream from the transcription start point (tsp), a nucleotide sequence highly homologous to the consensus sequence motif for the sigma 35-recognized promoters was found. Northern blot analysis has indicated that the expression of the gene is induced only at the midsporulation stage, and that the gene constitutes an operon with a downstream gene, mreB. The Bs strain carrying the spoIIID delta erm or spoIIID83 mutation completely restored sporulation ability upon introduction of the spoIIID homologous gene from Bt. These results strongly suggest that the gene we have cloned is a Bt homolog of spoIIID.

Amino Acid Sequence↗
PubMed2003

Protection of mice infected with Plasmodium berghei by Bacillus thuringiensis crystal proteins.

Eight Bacillus thuringiensis strains were used to test their activity against Plasmodium berghei. When crystal proteins extracted from strains 007, 017, 020, 021, 030, 032, and 037 were injected into plasmodium-infected mice through the tail vein at a rate of 0.45-1.5 mg per mouse, the lengths of survival for the mice were extended up to 5 days (from 8.5 days to 13.5-15 days). Blood-cell staining demonstrated that normal erythrocytes were lightly stained and regularly shaped while the erythrocytes from plasmodia-infected mice swelled, lost shape and even lysed. This means that the crystal proteins could protect erythrocytes from the plasmodium's attack. Proteins analysis revealed that most of the proteins are homologues of classic crystal proteins, with the exception of the 120-kDa protein of strain 020, a surface-layer protein. This study suggested a novel way to control plasmodial infections and even malaria.

Amino Acid Sequence↗
PubMed1987

Five-month oral (diet) toxicity/infectivity study of Bacillus thuringiensis insecticides in sheep.

Bacillus thuringiensis insecticides (Bt) [Dipel (test substance D or Thuricide-HP (test substance T)] were administered in the diet for 5 months to castrated mixed rambouillet/merino sheep (24-34 kg at the beginning of the study) at a dose of 500 mg/kg/day (approximately 10(12) spores per day). No treatment-related effect was seen on weight gain or clinical chemistry parameters nor were significant gross clinical changes observed. Several blood and tissue samples taken just prior to the time the animals were killed or at necropsy were found to be positive for Bt when cultured. Detailed gross and microscopic pathologic examination of the sheep revealed several incidental lesions. However, the only lesion that may have been associated with the treatment was lymphocytic hyperplasia in Peyer's patches seen in the cecum of three sheep and it was not considered to be clinically significant.

Administration, Oral↗
PubMed2004

A strategy for shuffling numerous Bacillus thuringiensis crystal protein domains.

Bacillus thuringiensis that produce Cry1Ba are toxic to Lucilia cuprina Wiedemann blow fly maggots in vivo, and when applied in quantity to sheep fleece, provide up to 6 wk protection against flystrike in the field. These strains also are toxic to Epiphyas postvittana (Walker) light brown apple moth caterpillars. B. thuringiensis expressing Cry1Db are toxic only to E. postvittana. When Cry1Ba and Cry1Db proteins are expressed within Escherichia coli, the recombinant bacteria have the same toxicity profile as the wild-type B. thuringiensis strain. In an effort to develop a Cry protein with improved blow fly toxicity, three different internal regions of Cry1Ba coding DNA, encoding all or part of domains I, II and III respectively were systematically exchanged with the corresponding region from a pool of other Cry protein coding DNAs. The chimeric products were then expressed in recombinant E. coli, and the resulting bacteria assayed for toxicity on L. cuprina and E. postvittana. Clones having insecticide bioactivity were characterized to identify the source of the replacement Cry domain. Despite successfully expressing a large number and variety of chimeric proteins within E. coli, many with measurable insecticidal activity, none of the chimeras had greater potency against L. cuprina than the wild-type Cry1Ba. Chimeric replacements involving domains I and II were rarely active, whereas a much higher proportion of domain III chimeras had some bioactivity. We conclude that shuffling of Cry coding regions through joining at the major conserved sequence motifs is an effective means for the production of a diverse number of chimeric Cry proteins but that such toxins with enhanced bioactive properties will be rare or nonexistent.

Animals↗
PubMed1961

Serological studies on the formation of protein parasporal inclusions in Bacillus thuringiensis.

A strain of Bacillus thuringiensis has been isolated, and methods have been developed for separation of the crystalline, parasporal inclusions in a pure form. Normal sporulation with concomitant crystal formation takes place when cells are incubated under suitable conditions in a nutrient free medium. Serological techniques have been used to study the origin and development of the crystals. Rabbit antisera have been prepared to a vegetative cell extract, suspensions of crystals, and a solution of crystal protein (obtained by alkali treatment of crystals). Tests have been carried out mainly by the Ouchterlony gel plate technique. Crystal protein solutions were found to be more active than suspensions of intact crystals both in reaction with, and in neutralization of, the crystal antibodies. Antisera to the vegetative cell extract gave no reaction with crystal protein. Ultrasonic extracts of cells taken before or during crystal formation gave no reaction with the crystal antibodies. Tests with alkali extracts of disrupted cells showed that the crystal antigen is absent in vegetative cells but arises during sporulation. The appearance of the antigen can be correlated with the formation and growth of the crystals as followed by examination of disrupted cell preparations under the electron microscope. It can be concluded that the crystalline protein inclusions do not arise from precursors in the same antigenic state.

Animals↗
PubMed2002

Silencing of midgut aminopeptidase N of Spodoptera litura by double-stranded RNA establishes its role as Bacillus thuringiensis toxin receptor.

Insecticidal crystal proteins of Bacillus thuringiensis bind to receptors in the midgut of susceptible insects leading to pore formation and death of the insect. The identity of the receptor is not clearly established. Recently a direct interaction between a cloned and heterologously expressed aminopeptidase (slapn) from Spodoptera litura and the Cry1C protein was demonstrated by immunofluorescence and in vitro ligand blot interaction. Here we show that administration of slapn double-stranded RNA to S. litura larvae reduces its expression. As a consequence of the reduced expression, a corresponding decrease in the sensitivity of these larvae to Cry1C toxin was observed. The gene silencing was retained during the insect's moulting and development and transmitted to the subsequent generation albeit with a reduced effect. These results directly implicate larval midgut aminopeptidase N as receptor for Bacillus thuringiensis insecticidal proteins.

Animals↗
PubMed2002

Cloning and characterization of an insecticidal crystal protein gene from Bacillus thuringiensis subspecies kenyae.

A sporulating culture of Bacillus thuringiensis subsp. kenyae strain HD549 is toxic to larvae of lepidopteran insect species such as Spodoptera litura, Helicoverpa armigera and Phthorimaea operculella, and a dipteran insect, Culex fatigans. A 1.9-kb DNA fragment, PCR-amplified from HD549 using cryII-gene-specific primers, was cloned and expressed in E. coli. The recombinant protein produced 92% mortality in first-instar larvae of Spodoptera litura and 86% inhibition of adult emergence in Phthorimaea operculella, but showed very low toxicity against Helicoverpa armigera, and lower mortality against third-instar larvae of dipteran insects Culex fatigans, Anopheles stephensi and Aedes aegypti. The sequence of the cloned crystal protein gene showed almost complete homology with a mosquitocidal toxin gene from Bacillus thuringiensis var. kurstaki, with only five mutations scattered in different regions. Amino acid alignment with different insecticidal crystal proteins using the MUTALIN program suggested presence of the conserved block 3 region in the sequence of this protein. A mutation in codon 409 of this gene that changes a highly conserved phenylalanine residue to serine lies in this block.

Amino Acid Sequence↗