• Journal of Microbiology and Biotechnology
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• 제14권4호
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• pp.772-776
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• 2004

Physiological and molecular characteristics of Bacillus thuringiensis SR6 and SR8 were investigated, and phase contrast and electron microscopies revealed that a large rhomboidal crystal protein was present in the sporulating cells. SDS-PAGE and Western blot analyses showed that B. thuringiensis SR8 produced 70 kDa protein much more than other proteins, and that the 70 kDa protein could bind to the antibody of B. thuringiensis subsp. tenebrionis-crystal toxin protein, indicating that the crystal 70 kDa protein has an immunological homology with B. thuringiensis subsp. tenebrionis-crystal toxin protein. The DNA fragment of B. thuringiensis subsp. tenebrionis-toxin gene was detected in B. thuringiensis SR6 and SR8 by using PCR amplification analysis. Furthermore, the insect bioassay showed the insecticidal activity against Colorado potato beetle larvae. Based on the physiological and molecular similarities to B. thuringiensis subsp. tenebrionis, it is suggested that the B. thuringiensis SR6 and SR8 may be mutants of the B. thuringiensis subsp. tenebrionis strain overexpressing the crystal of 70 kDa toxin protein.

• 한국잠사곤충학회지
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• 제35권2호
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• pp.129-133
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• 1993

Bacillus thruingiensis var. kurstaki HD-1의 내독소 단백질 유전자의 발현기작을 규명하기 위하여 이 균으로부터 내독소 단백질 유전자가 존재하는 것으로 확인된 29Md와 44Md plasmid를 분리한 후, Sau3AI 제어효소로 부분절단하고, pBR322 BamHI site에 ligation하여, E. coli HB101 strain에 transformation시켜, 3,000여개의 Ampr/Ters한 colony를 얻어 면역학적 방법과 살충적 검정으로 통해 재조합 균주 KC1을 얻었다. PKC1 plasmid DNA는 vector DNA를 포함하여 약 12kb 정도의 크기를 가지며, B. t k HD-1 내독소 단백질과 이동도가 같거나 일치하는 132kd, 117kd의 KC1 specific band 2개를 얻었다. KC1 cell extract를 첨식한 결과 약 80% 치사율을 보였다.

• Biodesign
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• 제7권2호
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• pp.35-37
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• 2019

Xanthomonas oryzae pv. oryzae (Xoo) is a plant pathogen, which causes a bacterial blight of rice. The bacterial blight is one of the most devastating diseases of rice in most of the rice growing countries and there is no effective pesticide against bacterial blight. The β-ketoacyl-acyl carrier protein synthase III (FabH) plays a key role in fatty acid synthesis (FAS) and is a promising drug target for the development of antibacterial agents. Xoo0878 gene, a fabH gene, from Xoo was cloned and its gene product Xoo0878 was expressed, purified and crystallized. Xoo0878 crystal diffracted to 2.1Å resolution and belonged to the triclinic space group P1, with unit-cell parameters a = 57.3Å, b = 64.7Å, c = 104.2Å and α = 81.6°, β = 84.7°, γ = 74.4°. There are four monomers in the asymmetric unit, with a corresponding crystal volume per protein weight of 2.65 ų Da^-1 and a solvent content of 53.6%. Xoo0878 structure will be useful to develop new antibacterial agents against Xoo.

• 한국응용곤충학회지
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• 제32권3호
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• pp.300-306
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• 1993

Bacillus thuringiensis subsp. kurstaki HD-1으로부터 생산된 살충성 내독소 단백질을 coding하는 CryIIA 유전자를 클로닝하고 염기서열을 조사하였다. HD-1 균주의 12개 plasmid 중 225kb plasmid를 분리하여 CryIIA 유전자를 포함하는 5kb HindIII 절편을 hybridization하여 찾아냈다. 이 절편을 plasmid pUC19에 ligation하여 E. coli에 형질 전환하였다. 이 독소 유전자를 포함하는 4kb BamHI-HindIII 절편은 vector pT7-5에 ligation하여 pSKIIA라하였다. pSKIIA는 3개의 open reading frames(orf1, orf2, orf3)로 구성되어 있으며 염기서열은 3,952base로 되어 있었다. 이러한 3개의 orf 각각의 발현 여부를 확인하기 위하여 생물검정을 하였다. 그러나 orf1 또는 orf2에 의한 형질 전환체는 독성이 없는 것으로 나타났다. orf3를 포함하는 형질 전환체는 3종의 나비목 곤충(배추점나방, 담배거세미나방, 담배나방) 및 1종의 파리목 곤충(집모기) 유충에 대하여 독성을 나타내었다.

• 한국미생물·생명공학회지
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• 제24권2호
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• pp.173-177
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• 1996

Bacillus thuringiensis subsp. morrisoni PG-14 is a gram-positive soil bacterium producing mosquitocidal parasporal inclusions composed of several crystal proteins. Among these crystal protein genes, cryIVD gene is one of major component which has 72 kDa in size. However, these parasporal inclusions sink quickly from the surface of water where mosquito larval feeding occurred. To develope mosquitocidal cyanobacterium, therefore, we constructed the expression vector, pCYASK 5-1 harboring cryIVD gene. The expression vector, pCYASK5-1 was transformed into the cyanobacterium Syne- chocystis PCC6803 reported as a natural mosquito larval food source and the transformants were selected with kanamycin. Expression of IVD gene in transformant was characterized by SDS-polyacrylamide gel electrophoresis (PAGE) and immunoblot analysis. The mosquitocidal activity of a transformant was determined with Culex tritaeniorhynchus. The results showed that, the transformed cyanobacterium is toxic to mosquito larvae and will be expected as a potential agent that is used for mosquito control.

• 대한바이러스학회지
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• 제29권3호
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• pp.145-153
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• 1999

We have now constructed a novel recombinant baculovirus Autographa californica nuclear polyhedrosis virus (AcNPV) producing polyhedra with Bacillus thuringiensis (Bt) CryIAc crystal protein. The recombinant polyhedra produced by the recombinant baculovirus, Btrus, in insect cells was characterized. The recombinant baculovirus has two independent transcription units in opposite orientations with two promoters, p10 or polyhedrin gene promoter each initiating transcription of either native polyhedrin or fusion protein with polyhedrin and Bt Cry1Ac crystal protein. Surprisingly, this recombinant baculovirus stably produced recombinant polyhedra which were nearly similar to those of wild-type AcNPV. The immunogold staining experiment showed that the recombinant polyhedra were assembled with polyhedrin and Bt Cry1Ac crystal protein, and contained virus particles. Insecticidal toxicity of recombinant polyhedra of Btrus to the fall webworm, Hyphantria cunea, was strikingly improved in comparison with the wild-type AcNPV.

• Journal of Microbiology and Biotechnology
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• 제1권4호
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• pp.240-245
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• 1991

We have constructed a promoter-probe vector pKU20 using pKT230, a derivative of broad-host-range plsmid RSF1010, as a base. The pKU20 contains structural gene for aminoglycoside phos-photransferase (aph), without promoter, and a multiple cloning site upstream the aph. Using this vector, a 412base pairs (bp) PstI fragment showing strong promoter activity both in Escherichia coli LE392 and Pseudomonas putida KCTC1644 has been cloned from Pseudomonas fluorescens chromosomal DNA on the basis of streptomycin resistance. The nucleotide sequence of the 412 bp fragment has been determined and the putative - 35 and -10 region was observed. Insecticidal protein gene of Bacillus thuringiensis subsp. kurstaki HD-73 inserted on downstream of the promoterlike DNA fragment was efficiently expressed in E. coli and P. putida. The toxin protein was efficiently synthesized in an insoluble form in both strains.

• 한국미생물·생명공학회지
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• 제21권5호
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• pp.428-434
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• 1993

Cloning and expression of two different crystal protein genes from transformed Bacillus thuringiensis were investigated. B. thuringiensis NT0423 is toxic to both Lepidopterous and Dipte-rous larvae. The pCG5 vector carrying crystal protein genes (mosquitocidal and hemolytic activity) of B. thurigiensis subsp. morrisoni PG-14 was transformed into B. thurigiensis NT0423. Transformant has expressed two type crystals of bipyramid from NT0423 and ovoid from pCG5 in one cell.

• International Journal of Industrial Entomology and Biomaterials
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• 제18권1호
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• pp.18-27
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• 2009

B. thuringiensis strain LY-99 belonging to subsp. alesti (H3a3c), was isolated from Chinese tobacco warehouse and showed significantly high toxicity to Plutella xylostella. For the identification of the cry1-type genes from B. thuringiensis LY-99, an extended multiplex PCRrestriction fragment length polymorphism (PCRRFLP) method was established by using two pairs of universal primers based on the conserved regions of the cry1-type genes to amplify around 2.4 kb cry1-type gene fragments. Then the DNA fragment was cloned into pGEM-T Easy vector and digested with EcoRI and EcoRV enzymes. Through this method, a known cry1-type gene was successfully identified from the reference strain, B. thuringiensis subsp. alesti. In addition, the RFLP patterns revealed that B. thuringiensis LY-99 included a novel cry1A-type gene in addition to cry1Aa, cry1Ac, cry1Be and cry1Ea genes. The novel cry1A-type gene was designated cry1Ah2 (Genbank accession No DQ269474). An inverse PCR method was used to amplify the flank regions of cry1Ah2 gene. Finally, 3143 bp HindIII fragment from B. thuringiensis LY-99 plasmid DNA including 5' region and partial ORF was amplified, and sequence analysis revealed that cry1Ah2 gene from LY-99 showed 89.31% of maximum sequence similarity with cry1Ac1 crystal protein gene. In addition, the deduced amino acid sequence of Cry1Ah2 protein shared 87.80% of maximum identity with that of Cry1Ac2. This protein therefore belongs to a new class of B. thuringiensis crystal proteins.

• 한국응용곤충학회지
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• 제43권1호
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• pp.35-41
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• 2004

Bacillus thuringiensis는 포자형성기 동안에 위생해충이나 농업해충에 독성을 보이는 내독소 단백질을 생성한다. 내독소 단백질의 모기 유충 방제효과를 높이기 위해, 광합성에 관여하는 psbA promoter로 모기 살충성 cry11Aa유전자를 발현하는 pSyn4D벡터를 제작하고, 모기 유충이 먹이로 이용하는 Synechocystis PCC6803에 형질 전환시켰다. 형질 전환체들은 kanamycin이 포함된 배지에서 선발되었으며, 정상적인 생물검정을 통해 형질 전환체 Tr2C를 선발하였다. cry11Aa 유전자는 형질전환체의 genomic DNA에 안정적으로 결합되어 있는 것을 PCR을 이용하여 확인하였다. 형질전환체 Tr2C는 약 72-kDa크기의 Cry11Aa 단백질을 발현하였으며, 작은빨간집모기(Culex tritaeniorhynchus) 3령 유충과 중국얼룩날개모기(Anopheles sinensis) 3령 유충에 75%가 넘는 살충력을 보였다. 모기 유충에 대한 형질전환체의 반수치사시간(LT$_{50}$)은 작은빨간집모기 유충과 중국얼룩날개모기 유충에 대해 각각 2.1일과 0.7일이었다. 이상의 결과들은 형질전환체 Tr2C가 모기 유충방제에 유용하게 이용될 수 있음을 보여준다.