• Korean journal of applied entomology
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• v.35 no.1
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• pp.85-90
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• 1996

Bacillus thuringiensis NT0423 produces quite a typical bipyramidal crystals of a common major band of ca. 130 kDa, and has dual specificity against Lepidoptera and Diptera. To enforce the Diptera-toxicity of B. thuringiensis NT0423, cryND gene was transformed 30 B. thuringiensis NT0423. The transfonnant B. thuringiensis PT1227 was obtained from introduction of pCGl0 into B. thuringiensis NT0423 by electroporation. The result showed that cryND and resident crystal protein genes in transformant were stably expressed with its own shape. Furthermore, the toxicity of B. thuringiensis PT1227 against Diptera was highly enforced, suggesting that the enforced toxicity of B. thuringiensis PT1227 was due to synergistic effect of both introduced and resident crystal proteins in transformant.

• Microbiology and Biotechnology Letters
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• v.21 no.5
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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.

• Korean journal of applied entomology
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• v.32 no.4
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• pp.426-432
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• 1993

Thirteen isolates of Bacillus thunngiensls producing parasporal mclusions, obtained from 45 samples of dust and soil of sericultural tarms in Kyeong-ki province, were exammed for their toxicity against larvae of Lepidoptera, Dipwra and Coleoptera. Of these isolates, Bacillus f thuringiensis NT0423 was toxic to bath Lepidoptera, and Dipteran larvae. NT0423 showed that the $LC_{50}$ values against the Lepldaptora, Plutella macuhpennis and the Diptera, Culex pipiens were $1.30\times10^6$ CFU/ml, $2.88\times10^5$ CFU/ml, respectively. The tYPlcal bipyramldal crystals produced by NT0423 composed of protoxms of 130-140kDa encoded by one or more plasm mid-horne genes. Also, plasmid DNA analysis indicated Lhat this isolate has 9 plasmids which d differ with reported several B. thuringiensis strains.

• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.2
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• pp.115-122
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• 2000

A Bacillus thuringiensis designated NT0423, belonging to B. thuringiensis subsp. aizawai (H 7), was isolated from samples of dust and soil of sericultural farms. B. thuringiensis NT0423 having dualspecificity against Lepidoptera and Diptera produced bipyramidal inclusions consisting of two major polypeptides of approximately 130- and 70-kDa. Proteolytic processing by trypsin and gut juice of Bombyx mori yielded predominant proteins with molecular masses of about 66-kDa. The whole crystal protein of B. thuringiensis NT0423 immunologically was related to that of B. thuringiensis subsp. aizawai. PCR analysis showed that B. thuringiensis NT0423 has at least five crystal protein genes including cryIA(a), cryIA(b), cryIC, cryID and cryIIA, and southern blot was determined the location of each gene on intact and enzyme-digested plasmid DNA fragments. Except for cryIA(a) gene on the high molecular weight plasmid of 165-kb, all of four genes were located on the plasmid of 66-kb. The production of $\beta$-exotoxin from B. thuringiensis NT0423 was identified by the HPLC analysis. In addition, the $\beta$-exotoxin showed its ability to prevent pupation of treated larvae of house flies (Musca domestica) from developing into normal adults.

• Journal of Sericultural and Entomological Science
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• v.37 no.2
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• pp.176-180
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• 1995

To characterize expression and formation of three type crystal proteins in transformant, Bacillus thruingiensis PT0529 was analysed by transmission electron microscope and SDS-PAGE according to growth. The results showed that the introduced crystal protein genes, rcyIVD and cytA, were well expressed at earlier stage than resident crystal proteins were also expressed with their own morphology. However, resident crystal protein of B. thuringiensis PT0529 was smaller than that of wild type B. thuringiensis NT0423, suggesting that resident crystal protein production was interfered with introduced two type crystal protein genes.

• Korean journal of applied entomology
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• v.37 no.2
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• pp.187-191
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• 1998

For efficient and economical production of Btrc,illus tlz~rr.ingi~r1~sstirsa in NT0423 as amicrobial-control agents, a new culture medium and culture condition were developed. Five mediadesignatzd as SWI I , SW14, SW23. SW32 and SW4I were prepared ~ : i t hv arious mixture ratio ofsoybean cake and wheat bran. It was founcl that in terms of the cell growth rate and development ofsporulation of B, thrri.il~girrl.sis strain NT0423 in all SW culture media were more efficient than those inGYS and in LB media. Total cell number in all SW media showed similar values, hut SW32 lnediilm wasthe most efficient in the development of spore, which amo~~ntetod 3.7 x 10XC FUImI. Also. at the pHranging frorn 6.2 to 7.3 in the mediiun~ no ad\:erse effect was not made in the culture of B. thur-ingicnsisstrain NT0423. The optimal volume (%) of SW32 mecliuni in a 5 1 fernientor was determined as 4 8\rolume of total niediuni. resulting ill growth (4.2 x 1OTCFUlrnl) of H. t1~~irir1,yirrz.ssit.vr ain NT0423. As H.t l i ~ t r i t ~ g iw~ a~s~ csuil~tu rcd in the shakc-flash and 5 1 fcrnientor. bacterial cells were yielded to 1 X 10"CFUIml and 5 x I O1oCFLJlml.FUIml and 5 x I O1oCFLJlml.

• Microbiology and Biotechnology Letters
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• v.26 no.4
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• pp.358-364
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• 1998

New microbial-control agents were prepared with B. thuringiensis strain NT0423 having unique properties which are different with other B. thuringiensis strains belonging to serotype 7[Kor. J. Appl. Entomol. 32: 426-432.]. Three B. thuringiensis formulations designated as BioBact 10%, 20% and 40%, were made with various combinations of adjuvants. These formulations showed good physical properties in wettability, suspensibility, particle size and adherence. In addition the result of SDS-PAGE analysis indicated that $\delta$-endotoxins remain stably in all formulations. Among the tested formulations, two wettable powder formulations, BioBact 20% and 40%, comprising 20% and 40% of B. thuringiensis technical powder showed the effective control against diamondback moth larvae (Plutella xylostella) in laboratory and field tests. Especially, when compared with commercial B. thuringiensis formulations (A and B commercial formulations) in field evaluation, BioBact 20% and 40% formulations showed equal activity up to 80% lethality and a good persistence effect which remain on leaves at least 7 days.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.319-327
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• 2016

Chemical pesticides have been used to control persimmon pests, however the overuse of the pesticides caused insect resistance, followed by failure in pest management and residual problems. Herein we investigate the potential of eco-friendly organic pesticides (EFOP) on the control persimmon pests, Stathmopoda masinissa (persimmon fruit moth) and Riptortus pedestris (bean bug). Ten commercially available plant-derived organic pesticides and one microbial pesticide were sprayed on the target insects in laboratory conditions. The chemical pesticide, buprofezin+dinotefuran wettable powder served as a positive control. In the first bioassay against persimmon fruit moth, alternatively Plutella xylostella larvae were used due to the lack of persimmon fruit moth population from fields, and three organic pesticides showed high control efficacy, such as pyroligneous liquor (EFOP-1), the mixture of Chinese scholar tree extract, goosefoot and subtripinnata extracts (EFOP-2) and Bacillus thuringiensis subsp. aizawai NT0423 (EFOP-11). When the three selected organic pesticides were treated on the persimmon fruit moths, the EFOP-2 treatment showed the highest control efficacy: 27.7% (5 days), 13.3% (7 days) and 6.7% (10 days) of survival rates. In the bioassay against bean bugs, the mixture of Chinese scholar tree, goosefoot and subtripinnata extracts (EFOP-2 and EFOP-9) and the extracts of sophora and derris (EFOP-10) showed high control efficacy, particularly the highest in the treatment of EFOP-2: 20.0% (5 days) and 16.7% (10 days) of survival rates. These results suggest that the mixture of Chinese scholar tree, goosefoot and subtripinnata extracts (EFOP-2) has high and multiple potential in the management of the persimmon pests.