• Microbiology and Biotechnology Letters
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• v.25 no.4
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• pp.359-366
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• 1997

The usefulness of host range expanded recombinant viruses for economical viral insecticide and expression vector system has been studied. Host range expanded recombinant viruses, RecS-B6 and RecB-8, constructed by cotransfection of Bombyx mori nuclear polyhedrosis virus (BmNPV) and Autographa californica NPV (AcNPV), and a host range expanded AcNPV recombinant, Ac-BH, constructed by substitution of the 0.6Kb fragment of the BmNPV helicase gene were compared. The restriction enzyme digestion patterns showed that RecS-B6 and RecB-8 had expanded host ranges by genomic recombination and were more similar to genome of AcNPV than that of BmNPV. SDS-PAGE and PCR analysis showed that the polyhedrin gene of RecS-B6 and RecB-8 was derived from BmNPV genomic DNA. The morphology of polyhedra of recombinant viruses showed a slight difference between the two host cells, Sf and BmN cells, indicating that the morphology of polyhedra was influenced by host cells. The bioassay data for insect larvae showed that Ac-BH, compared to wild type viruses, had superior pathogenicity against Bombyx mori larvae but inferior pathogenicity against Spodoptera exigua larvae. Although the pathogenicity was lower than that of wild type viruses in both larvae, RecS-B6 showed the pathogenicity in both larvae. These results suggested that Ac-BH was a less useful economical insecticide than random genomic recombinant virus RecS-B6.

• Journal of Microbiology and Biotechnology
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• v.21 no.7
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• pp.675-678
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• 2011

DNA methylation in Streptomyces griseus IFO 13350 was analyzed by high-performance liquid chromatographic analysis and bisulfite-based analysis to reveal two methylation sites, 5'-$GC^{5m}$ CGGC-3' and 5'-$GAG^{5m}$ CTC-3'. The methylation was reconstituted in Escherichia coli by simultaneous expression of S. griseus SGR4675 and S. achromogenes M.SacI. The E. coli cells produced plasmids that mimicked the methylation profile of S. griseus DNA, which was readily introduced into S. griseus. The results of this study raise the possibility of a promising approach to establish efficient transformation in several streptomycetes.

• The Journal of Korean Society of Virology
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• v.27 no.1
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• pp.29-37
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• 1997

To use recombinant viruses with wider host range as viral insecticides, we investigated the characteristics and pathogenicity of host range expanded recombinant viruses in insect cells. We compared host range expanded recombinant viruses, RecS-B6 and RecB-8, constructed by cotransfection of Autographa californica nuclear polyhedrosis virus (AcNPV) and Bombyx mori NPV (BmNPV), to host range expanded AcNPV, Ac-BH, by substitution of the 0.6 Kb fragment of the BmNPV helicase gene. Restriction endonuclease profiles of RecS-B6 and RecB-8 DNAs were different from those of parent viruses. Nucleotide sequence analysis of the 0.6 Kb region in the putative helicase gene of RecS-B6 and RecB-8 showed that their structures were identical to the counterpart region of BmNPV. Comparison of viral replication of these recombinant viruses in Sf-21 and BmN-4 cells showed that Ac-BH, compared to wild type viruses, replicated well in BmN-4 cells but poorly in Sf-21 cells. In contrast, RecS-B6 and RecB-8 replicated relatively well in both cells compared to parent viruses. These results may imply that random genomic recombinant viruses, RecS-B6 and RecB-8, possess better potential as viral pesticides than helicase-mediated recombinant virus, Ac-BH.

• Korean Journal of Microbiology
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• v.22 no.4
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• pp.249-255
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• 1984

To develop the host-vector system for industrial Coryneform bacteria that seemed to be the most suitable microorganisms for molecular breeding of genes involved in the production of amion acids, nucleotides, and other products of industrial interest, broad host range E. coli plasmid R 1162 DNA was transformed into Brevibacterium ammoniagenes and the plasmids pKU6 isolated from a transformant was physically characterized. All other plasmids from the transformed cells except pKU6 exsisted as multimeric forms in Brevibacterium ammoniagenes. The plasmid DNA was retransformed into Corynebacterium glutamicum with a high frequency ($1.32{\times}10^{-1}$ per cell) and maintained stably both in Brevibacterium ammoniagenes and Corynebacterium glutamicum after 100 generations of cultures with 25-30 copy number per cell. The size of both plasmid pKU6 and plasmid R1162 were the same and restriction maps by EcoR I, Ava I, Pst I, Pvu II and Hinc II were also similar.

• Korean Journal of Microbiology
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• v.28 no.1
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• pp.35-40
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• 1990

The restriction clevage map of multi-copy recombinant plasmid, pJY712(8.1kb), carrying the thiostrepton resistance gene(tsr) was determined. pJY712 had a broad host range in Streptomyces and contained single BglII site for cloning purpose. The plasmid showed the phenomenon of lethal zygosis ($Ltz^{+}$). Transformation frequency of pJY712 was $5.0\times 10^{4}$ transformants per ug plasmid DNA (TFU) in S. lividans. Plasmid pJY713 was constructed by inserting the tyrosinase gene(mel) into the BclI site of pJY712. Recombinant plasmid pJY714 carrying the mel gene was constructed by in vitro deletion of a segment (1.9kb BglII-BclI fragment) from pJY713.

• The Plant Pathology Journal
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• v.16 no.6
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• pp.306-311
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• 2000

A new strain of Cucumber mosaic virus (CMV) from easter lily (Lilium longiflorum), Ly2-CMV, was identified and compared to the well-characterized Mf-CMV (subgroupⅠ) and LS-CMV (subgroupⅡ) by host reaction in several indicator plants, dsRNA analysis, serological property, RT-PCR analysis, restriction enzyme profile of the PCR products and nucleotide sequence of coat protein (CP) gene. Remarkable differences in symptoms of Ly2-CMV were found between Mf-CMV or LS-CMV in tobacco plants and Datura stramoinium. Ly2-CMV induced small necrotic ringspots on the inoculated leaves of Nicotiana tabacum cvs. Xanthi nc and Burley 21 and D. stramonium, and failed to infect these species systemically. Of the indicator plants tested, N. benthamiana only reacted with systemic infection by inoculation of Lr2-CMV. In experiments of dsRNA analysis, serology and RT-PCR of CP gene, Ly2-CMV was come within subgroupⅠ CMV. However, restriction enzyme analysis of the PCR products using MspⅠ showed that Ly2-CMV was distinct to Mf-CMV. The CP gene of Ly2-CMV contains 657 nucleotides, and the nucleotide sequence is similar to that of Mf-CMV. There is also a high degree of conservation between their putative gene products in Ly2-CMV and Mf-CMV, with five amino acid changes in the 218 amino acids of the CPs.

• Research in Plant Disease
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• v.14 no.3
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• pp.229-232
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• 2008

An isolate of Cucumber mosaic virus (CMV), designated as Cas-CMV, was isolated from Chinese aster (Callistephus chinensis) showing severe mosaic symptom, and its properties was compared to the well-characterized Fny-CMV (subgroup IA) and As-CMV (subgroup IB) by host reaction in several indicator plants, dsRNA analysis, RT-PCR analysis, and restriction enzyme profile of the PCR products. Cas-CMV differed markedly in their host reaction to Fny-CMV or As-CMV in Cucurbita pepo cv. Black beauty. In the zucchini squash, all strains induced chlorotic spot on inoculated leaves and mosaic symptoms on upper leaves. However, symptoms induced by Cas-CMV were developed lethal necrosis on the young plants 15 to 20 days after inoculation. In experiments of dsRNA analysis and RT-PCR analysis, properties of Cas-CMV was come within subgroup I CMV. Moreover, restriction enzyme analysis using HindIII of the RT-PCR products showed that Cas-CMV belong to a member of CMV subgroup IA.

• Journal of Microbiology
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• v.33 no.3
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• pp.208-214
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• 1995

The effects of various 2, 4-D-degradative plasmids on the axenic growth patterns, the degradation phenotypes, and the competitiveness of different host bacteria were evaluated in liquid cultures; the organisms and plasmids used were Alcaligenes eutrophus JMP134/pJP4, Alcaligenes paradoxus/p2811, Pseudomonas pickettii/p712, pJP4, and p712 or p 2811 exhibited very different restriction fragment profiles in restriction endonuclease digests. These plasmids were transferred to the recipients (P. cepacia and Alcaligenes JMP228) at relatively high frequencies ranging from 8.9 $\times$ 10$^3$ to 1.6 $\times$ 10$^5$ per donar cell. In the axenic liquid cultures the fast-growing strains, such as P. pseudomallei/p745 and P. cepacia/pJP4, exhibited short lag periods, high specific growth rates, and high relative fitness coefficients, while the slow-growing strains, such as P. pickettii/p712 and A. paradoxus/p2811, had long lag periods, low specific growth rates, and low relative fitness coefficients. Depending on the type of plasmid containing the genes for the 2, 4-D pathway, some transconjugants exhibited intermediate grwoth patterns between the fast-growing strains and the slow-growing strains. The plasmid and plasmid-host interactions determined specific growth rate and lag time, respectively, which were shown to be principal determinants of competitiveness among the strains, but relative fitness coefficient derived from the axenic culture was not always predictive for the mixed culture condition.

• Journal of Environmental Science International
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• v.5 no.5
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• pp.605-610
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• 1996

The bacteriophage from the fresh oyster, Crassostrea Virginica which is specific to the marine bacterium was isolated and characterized. Among the foci different vibrio species and the five different serotypes of Vibrio parahaemolyticus host strains tested, only two strains of the parahaemolyticus possessing K17, K52 antigens were highly sensitive to the phage. The size of the isolated plaque was 0.4mm and the electron microscopic head size of the isolated phage was about 67 nm long and 83 nm wide. PFU/ml was 1.25$\times$ $10^{11}$. The phase was sensitive to chloroform but resistant to acetone or methanol. The assay of the isolated phase nucleic acid was deoxyribonucleic acid. The restriction enzyme pattern showed 14 fragment from Hind III and 4 fragments from Eco R I. Two different antigenic groups showed-similar restriction enzyme patterns.

• Parasites, Hosts and Diseases
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• v.39 no.1
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• pp.43-48
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• 2001

We have studied the genetic differences among four isolates of Trichinella including a new strain of Trichinella spiralis (ISS 623) recently found from a human case who took a badger in Korea. Because they have a different host origin and came from geographically separated regions, we supposed the genetic pattern of the isolates might be different as had been previously reported. It was analysed by PCR-RFLP analysis of the rDNA repeat that can readily distinguish a species or strain from others. Isolated genomic DNA of each isolate of Trichinella larvae was amplified with ITSl specific primers and digested with restriction endonucleases. The PCR product of ITSl was confirmed using Southern blot analysis to be a 910 Up fragment. The restriction fragments of each isolate had variable patterns when it was digested with Rsa I only. According to the RFLP patterns, the estimated genetic divergence between each isolate was different. In conclusion, four isolates of Thichinella including a new strain of T. spiralis obtained from a Korean patient may have genetic differences in the ITSl region and the Shanghai isolate was genetically more similar to the Japanese unknown isolate than others in the ITSl region.