A facile analytical method for the identification of protease gene profiles from Bacillus thuringiensis strains

AbstractWe estimated the usefulness of spore-crystals preparations of the twoB. thuringiensisisolates, MPU B9 and MPU B54, for reducing the number of pests. The potential insecticidal toxicities ofB. thuringiensisisolates were assessed by the analysis of the genes coding for crystalline proteins. The activities of spore-crystals preparations were determined againstDendrolimus piniL. (Lepidoptera: Lasiocampidae) and compared with the toxicity of spores and crystals ofB. thuringiensissubsp.kurstakiHD-1 from commercial biopesticide Foray. Although the analysis of crystalline toxin gene profiles indicated potentially higher activities of MPU B9 and MPU B54 crystals against the pests than that of HD-1, the toxicities of isolate and HD-1 preparations againstD. pinicaterpillars were similar. The LC50amounted to 3.42×104spores and crystals for HD-1, 3.36×104for MPU B9 and 3.5×104for MPU B54. Additionally, the toxicity of the MPU B54 preparation was evaluated againstSpodoptera exigua(Hubner) (Lepidoptera: Noctuidae). The LC50was 4.5×105spores and crystals of MPU B54, and 2.69×106spores and crystals of HD-1. The LC50of the MPU B54 preparation againstS. exiguawas approximately six-fold higher than that of HD-1. However, due to the very wide fiducidal limits for LC50values, which for both preparations overlap to a large extent, the toxicity of the preparations should be considered the same. The varied profiles of crystalline toxin genes and important toxicity of spore-crystal mixtures of isolates againstS. exiguaandD. piniindicate the effectiveness of the mixtures against pests and make the strains an alternative for HD-1 for reducing the number of insects.

Download Full-text

Dissection of cry Gene Profiles of Bacillus thuringiensis Isolates in Taiwan

Current Microbiology ◽

10.1007/s00284-003-4195-1 ◽

2004 ◽

Vol 48 (4) ◽

pp. 270-275 ◽

Cited By ~ 12

Author(s):

Fu-Chu Chen ◽

Ming-Chu Tsai ◽

Cheng-Hung Peng ◽

Kin-Fu Chak

Keyword(s):

Bacillus Thuringiensis ◽

Cry Gene ◽

Gene Profiles

Download Full-text

Population structure and toxin gene profiles of Bacillus cereus sensu lato isolated from flour products

FEMS Microbiology Letters ◽

10.1093/femsle/fnz240 ◽

2019 ◽

Vol 366 (20) ◽

Cited By ~ 4

Author(s):

Patrick Kindle ◽

Danai Etter ◽

Roger Stephan ◽

Sophia Johler

Keyword(s):

Risk Assessment ◽

Population Structure ◽

Bacillus Thuringiensis ◽

Bacillus Cereus ◽

Toxin Gene ◽

Type Iii ◽

Gene Profiles ◽

Enterotoxin Genes ◽

Parasporal Crystals ◽

Bacillus Cereus Sensu Lato

ABSTRACT Data on the occurrence, population structure and toxinogenic potential of Bacillus cereus sensu lato isolated from flour is essential to enable improved risk assessment. We aimed to provide data on the occurrence of B. cereus sensu lato in flour products at retail level. In addition, we screened the isolates for Bacillus thuringiensis and Bacillus cytotoxicus and determined population structure and toxin gene profiles. We screened 89 flour products for presence of B. cereus sensu lato, resulting in 75 positive samples (84%). We were able to show that the population structure of members of the B. cereus group isolated from flour is highly diverse. Isolates were assigned to panC types II (4%), III (21%), IV (39%) and V (36%). Production of parasporal crystals characteristic for Bacillus thuringiensis was detected in seven isolates assigned to panC type III, IV and V. No B. cytotoxicus were detected. Two of the isolates harbored ces encoding cereulide, which causes the emetic syndrome. Various enterotoxin genes were found, with all isolates harboring nhe, 75% of isolates harboring hbl and 51% of the isolates harboring cytK-2. Our findings suggest that toxinogenic B. cereus sensu lato are common in flour products at retail level.

Download Full-text

Production of Cry11A and Cry11Ba Toxins in Bacillus sphaericus Confers Toxicity towards Aedes aegyptiand Resistant Culex Populations

Applied and Environmental Microbiology ◽

10.1128/aem.65.7.3021-3026.1999 ◽

1999 ◽

Vol 65 (7) ◽

pp. 3021-3026 ◽

Cited By ~ 33

Author(s):

Pascale Servant ◽

Marie-Laure Rosso ◽

Sylviane Hamon ◽

Sandrine Poncet ◽

Armelle Delécluse ◽

...

Keyword(s):

Bacillus Thuringiensis ◽

Culex Pipiens ◽

Recombinant Strain ◽

Bacillus Sphaericus ◽

Binary Toxin ◽

Protease Gene ◽

Gene Encoding ◽

In Vivo Recombination ◽

Target Sites

ABSTRACT Cry11A from Bacillus thuringiensis subsp.israelensis and Cry11Ba from Bacillus thuringiensis subsp. jegathesan were introduced, separately and in combination, into the chromosome of Bacillus sphaericus 2297 by in vivo recombination. Two loci on theB. sphaericus chromosome were chosen as target sites for recombination: the binary toxin locus and the gene encoding the 36-kDa protease that may be responsible for the cleavage of the Mtx protein. Disruption of the protease gene did not increase the larvicidal activity of the recombinant strain against Aedes aegyptiand Culex pipiens. Synthesis of the Cry11A and Cry11Ba toxins made the recombinant strains toxic to A. aegyptilarvae to which the parental strain was not toxic. The strain containing Cry11Ba was more toxic than strains containing the added Cry11A or both Cry11A and Cry11Ba. The production of the two toxins together with the binary toxin did not significantly increase the toxicity of the recombinant strain to susceptible C. pipiens larvae. However, the production of Cry11A and/or Cry11Ba partially overcame the resistance of C. pipiens SPHAE andCulex quinquefasciatus GeoR to B. sphaericus strain 2297.

Download Full-text

Densitometric Identification of Primitive Erythroblasts After Reaction With Diaminobenzidine

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100072083 ◽

1973 ◽

Vol 31 ◽

pp. 328-329

Author(s):

John A. Trotter

Keyword(s):

Red Blood Cells ◽

Analytical Method ◽

Blood Cells ◽

Guinea Pigs ◽

Specific Protein ◽

Visual Examination ◽

Hemoglobin Synthesis ◽

Peroxidatic Activity ◽

Small Density

Hemoglobin is the specific protein of red blood cells. Those cells in which hemoglobin synthesis is initiated are the earliest cells that can presently be considered to be committed to erythropoiesis. In order to identify such early cells electron microscopically, we have made use of the peroxidatic activity of hemoglobin by reacting the marrow of erythropoietically stimulated guinea pigs with diaminobenzidine (DAB). The reaction product appeared as a diffuse and amorphous electron opacity throughout the cytoplasm of reactive cells. The detection of small density increases of such a diffuse nature required an analytical method more sensitive and reliable than the visual examination of micrographs. A procedure was therefore devised for the evaluation of micrographs (negatives) with a densitometer (Weston Photographic Analyzer).

Download Full-text

Bulk standards for low-temperature biological x-ray microanalysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100111525 ◽

1984 ◽

Vol 42 ◽

pp. 282-283

Author(s):

P. Echlin ◽

M. McKoon ◽

E.S. Taylor ◽

C.E. Thomas ◽

K.L. Maloney ◽

...

Keyword(s):

Phase Separation ◽

Low Temperature ◽

Analytical Method ◽

Salt Solutions ◽

Absolute Concentration ◽

Cooling Process ◽

X Ray ◽

The Absolute ◽

Analytical Procedures ◽

Electrical Conductors

Although sections of frozen salt solutions have been used as standards for x-ray microanalysis, such solutions are less useful when analysed in the bulk form. They are poor thermal and electrical conductors and severe phase separation occurs during the cooling process. Following a suggestion by Whitecross et al we have made up a series of salt solutions containing a small amount of graphite to improve the sample conductivity. In addition, we have incorporated a polymer to ensure the formation of microcrystalline ice and a consequent homogenity of salt dispersion within the frozen matrix. The mixtures have been used to standardize the analytical procedures applied to frozen hydrated bulk specimens based on the peak/background analytical method and to measure the absolute concentration of elements in developing roots.

Download Full-text

Distinct Differences in Monocyte Gene Profiles Between Men and Women With PTSD

PsycEXTRA Dataset ◽

10.1037/e517292011-347 ◽

2009 ◽

Author(s):

Thomas Neylan ◽

Bing Sun ◽

Maryann Lenoci ◽

Hans Rempel ◽

Lynn Pulliam

Keyword(s):

Men And Women ◽

Gene Profiles

Download Full-text