• Journal of Sericultural and Entomological Science
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• v.36 no.2
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• pp.157-161
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• 1994

To investigate the morphology of Bacillus thuringiensis crystal proteins, two type crystal protein genes, cryIA(c) gene under the control of cryIA(b) gene promoter and cryIIA gene under the control of its own promoter, were transformed in B. thuringiensis acrystalliferous mutant strain and the transformants were characterized by SDS-PAGE and scanning electron microscopy. The expression and formation of crystal proteins in B. thuringiensis subsp. kurstaki Cry-B revealed that crystal proteins appear to have same molecular weight and morphology to those of wild type strain's, suggesting that the expression and formation of crystal proteins affected not by host cell or recombination of cryIA(e) gene under the control of cryIA(b) gene promoter but by only structural fragment of protoxin.

• Microbiology and Biotechnology Letters
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• v.23 no.1
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• pp.110-117
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• 1995

This study was carried out to immunologically characterize Bacillus thuringiensis (B.t) antigens. Protein patterns of ultrasonicated- antigens of B. thuringiensis subspecies using SDS- PAGE revealed marked similarities among all the strains analyzed except for the difference between quantative variations of bands and some protein antigens. The comparison of the protein patterns showed that the protein antigen of 45 kilodalton (kd) was common in 11 strains and that the difference between B. thuringiensis subsp. canadensis and galleriae was noticed in quantative variations of bands despite of ambiguous serogrouping, suggesting a useful method for identification. All strains examined showed similar antigenic patterns in SDS-PAGE, while immunodominant bands differed in antigenic reactivity in western blot using polyclonal antibodies. Polyclonal antibody to B. thuringiensis subsp. thuringiensis and israelensis in indirect immunofluorescence assay reacted with flagella and cell surface antigens. The present study indicates that SDS-PAGE and western blot analysis may be used as tools for differentiation and identification of B. thuringiensis subspecies.

• Microbiology and Biotechnology Letters
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• v.27 no.5
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• pp.359-363
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• 1999

To prevent appearance of resistant mosquitoes against $\delta$-endotoxin of bacillus thuringiensis subsp. israelensis (Bti) in field, a mosquitocidal Bacillus thuringiensis strain 21-2(Bt21-2) producing a new type of $\delta$-endotoxin was isolated. The strain Bt 21-2 belongs to H serotype 43, B. thuringiensis subsp. guiyangiensis (Btg). The $\delta$-endotoxins from the strain Bt 21-2 and the strain Bti were a cuboid shape morphologically, but the $\delta$-endotoxin of the strain Bt 21-2 was composed of 150, 90 and 70kDa proteins on SDS-PAGE, and the antigenicity of $\delta$-endotoxin of the strain Bt 21-2 was different from that of the strain Bti on immunoblot. The $\delta$-endotoxin gene of the strain Bt 21-2 was not amplified with specific primers of $\delta$-endotoxin gene (cry4A and cry4B) of the strain Bti on PCR.

• Journal of environmental and Sanitary engineering
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• v.13 no.2
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• pp.34-39
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• 1998

For more convenient and rapidly isolation of Bacillus thuringiensis subsp. israelensis(Bti), 1) heat treatment spore forming bacteria, 2) growth in enrichment culture media for Bacillus sp. and 3) selection of bacteria producing a lecithinase for Bacillus thuringiensis subsp. israelensis, were performed. Spore forming bacteria were counted 4.8 $\times $ 10$^{8}$cells/g soil on NAPGCY media, 9.2 $\times $ 10$^{7}$cells/g soil on NA media, and 3.6 $\times $ 10$^{8}$cells/g soil on NAAC media, respectively. Bacteria producing only a lecithinase were reached at 25.2% on medium contained egg york, bacteria only producing a delta-endotoxin were reached at 23.2% by phase contrast microscope, and bacteria producing a lecithinase & a delta-endotoxin simultaneously were reached at 13.7%. Bacillus thuringiensis which producing a lecithinase and a delta-endotoxin simultaneously among bacteria producing a lecithinase, were reached at 56.5%; A half of Bacillus thuringiensis was produced a delta-endotoxin, but not produced a lecithinase. Among 8 isolates of Bacillus thuringiensis, two strain of Bti which has a mosquito-cidal toxin, were detected by PCR using a specific primer of $\delta $-endotoxin gene from Bti.

• International Journal of Industrial Entomology and Biomaterials
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• v.3 no.1
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• pp.19-23
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• 2001

Two B. thuringiensis strains, which possess mosquitocidal activities, were isolated from Korean soil samples and named K-1205-1 and K-1381-1. Serological studies indicated that K-1205-1 and K-1381-1 belonged to B. thuringiensis subsp. kurstaki (H3a3b3c) and subsp. aizawai (H7), respectively. K-1205-1 produced typical bipyramidal parasporal inclusions, but K-1381-1 produced irregular bipyramidal shape. Total plasmid DNA patterns analysis shewed that K-1205-1 and K- 1381-1 were different from their reference strains, subsp. kurstaki and subsp. aizawai, respectively, in high molecules, whereas their crystal protein patterns showed no difference. The cry gene contents of K-1205-1 and K-1381-1 were identical with those of the reference strains. Mosquitocidal activities of crystal proteins produced by K-1205-1 and K-1381-1 were significantly high by about 40-50 folds at $LC_50$ when compared to those of subsp. kurstaki and subsp. aizawai. Finally, in southern blot analysis using cry1A-type specific probe, K-1205-1 and K-1381-1 had different bands from subsp. kurstaki and subsp. aizawai, respectively. In conclusion, our results suggest that K-1205-1 and K-1381-1 appear to be new moquitocidal B. thuringiensis strains isolated from Korean soil.

• Korean journal of applied entomology
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• v.35 no.1
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• pp.66-73
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• 1996

For the effective control of mosquito larvae, Anopheles sinensis, the expression vector pCYASK5-1 containing cryIVD gene of Bacillus thuringiensis subsp. morrisoni PG-14 was constructed and transformed into the cyanobacterium Synechocystis PCC6803. The transformants were selected on BG-11 medium containing kanamycin. The expression of cryIVD gene in transformant was confirmed by SDS-PAGE and Western blot analysis. The mortality of A. sinensis larvae was scored for 3 days. Furthermore, growth and distribution rate of transformant were examined. The results showed that Synechocystis PCC6803 transformed with cryIVD gene of B. thuringiensis subsp. morrisoni PG-14 was highly toxic to A. sinensis larvae, demonstrating that it will be a potential agent for mosquito control.

• Microbiology and Biotechnology Letters
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• v.19 no.3
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• pp.308-312
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• 1991

The delta-endotoxin from B. thuringiensis subsp. damstadienszs 73E10-2 was resistant to high concentration of salt (4M NaBr), organic solvents (50% acetone), denaturants (4 M urea), and neutral detergents (10% triton X-100). In contrast, the toxin was inactivated by treating with charged detergents as well as guanidine hydrochloride or carbon tetra-chloride. The delta-endotoxin is not a sulfhydryl activated toxin, but modification of the lysine side chains eliminated toxicity against mosquito larvae.

• Korean journal of applied entomology
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• v.47 no.2
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• pp.175-184
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• 2008

To screen highly active Bacillus thuringiensis isolates against Spodoptera litura (Lepidoptera, Noctuidae), 46 B. thuringiensis was isolated from 115 samples obtained from several crop soils. Especially, B. thuringiensis subsp. kurstaki CAB133 and CAB162 isolates showed 100% mortality against S. litura. $LD_{50}$ values of CAB 133, CAB162 and HD-1 strains of B. thuringiensis subsp. kurstaki were 0.089, 3.144 and $0.513{\mu}g/ml$ against 2nd larva of S. litura, respectively. The weight of 3rd larva of S. litura which were fed crystal inclusion protein $(1.267{\mu}g/ml)$ with B. thuringiensis subsp. kurstaki CAB133 was about 30 times lass than control group. CAB133 and CAB 162 strains of B. thuringiensis subsp. kurstaki which were taken a highly toxity against S. litura were analyzed by SDS-PAGE, and estimated the molecular weight of the Cry proteins. Their serological identification by H serotypes were showed B. thuringiensis subsp. kurstaki (3abc) type.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.2
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• pp.183-186
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• 2004

Recently, we have developed an easy, simple and convenient circular DNA cloning system named plasmid capture system (PCS). To investigate usefulness of PCS in cloning of plasmids from Bacillus thuringiensis strains, PCS donors, pPCS-S and pPCS-L were applied to clone plasmids of B. thuringiensis subsp. israelensis by in vitro transposition using 4{TnsABC^*}$ transposase. In result, 3 small plasmids were cloned, and these were consistent with pTX14-1, pTX14-2 and pTX14-3 reported previously from B. thuringiensis subsp. israelensis. Therefore, the PCS can be successfully applied to clone small plasmids from B. thuringiensis strains.

• Microbiology and Biotechnology Letters
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• v.15 no.6
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• pp.425-429
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• 1987

The extra-cellular hemolysin from Bacillus thuringiensis subsp. israelensis was purified in the process of suiting with (NH$_4$)$_2$SO$_4$, Sephadex G-200 gel filtration, and DEAE-cellulose column chromatography. The purified hemolysin had molecular weight of approximately 47,000 dalton on SDS-polyacrylamide gel electrophoresis. The activity of purified hemolysin on human red blood cells was increased by thiol agents, but that was Inhibited by cholesterol, protease treatment, and metal salts such as CuSO$_4$, and FeSO$_4$, respectively.