• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.182-195
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• 2000

Indigenous bacteria from poplar roots (Populus mnadensis var. eugenei, 'Imperial Carolina') and Southern Californian shrub rhizospheres as well as two tree-colonizing Rhizobium strains (ATCC 10320 and 35645) were genetically engineered to express constitutively and stably toluene o-monooxygenase (TOM) from Burkholderia cepacia G4 by integrating the torn locus into the chromosome. The poplar and Rhizobium recombinants degraded trichloroethylene (TCE) at 0.8-2.1 nmol/min.mg protein (initial TCE concentration, 10u M) and competitive against the unengineered hosts in wheat and barley rhizospheres for one month (colonization at 1-23 $\times$ 10$^{5}$ CFU/cm root). In addition, six of these recombinants colonized poplar roots stably and competitively with populations as high as 79 $\pm$ 12% of all rhizosphere bacteria after 28 days (0.2-31 $\times$ 10$^{5}$ CFU/cm root). Furthermore, five of the most-competitive poplar recombinants (e.g., Pb3-1 and Pb5-1 which were identified as Pseudomonas PsK) retained the ability to express TOM for 29 days as 100 $\pm$ 0% of the recombinants detected in the poplar rhizosphere had constitutive expression of TOM.

• Microbiology and Biotechnology Letters
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• v.18 no.3
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• pp.296-300
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• 1990

For interspecific portoplast fusion, Brevibacterium flauum lOAHR (Rifr axg his) and Corynebacterium glutamicum 11TS ($Sm-r$ trp) were induced by UV and NTG treatment. The protoplast fusion frequency between E. flavum XOAHR and C. glutamicum llTS was $3.7\times 10^{-6}$ with the lysozyme treatment (300 P $\mu g$ml) for 18 hrs. Genotypes of recombinants were analized as FMM ($Rif^r\; Sm^r$), FA (Rift $Sm^r$ arg), FH ($Rif^r\; Sm^r$ his), FT ($Rif^r\; Sm^r$ trp), FAH ($Rif^r\; Sm^r$ arg trp), FAT ($Rif^r\; Sm^r$ arg trp), and FAHT ($Rif^r\; Sm^r$ arg his trp). FAH 1 produced 12 fold of glutamate production compared to parental type, E. flauum 10AHR. In glutamine productivity, it produced 2.6 fold to parental type, C. glutamicum 11TS. Production of glutamate or glutamine by recombinants was involved in the specific activities of glutamate dehydrogenase (GDH) and glutamine synthetase (GS), respectively.

• Microbiology and Biotechnology Letters
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• v.14 no.4
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• pp.319-324
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• 1986

After intraspecific fusion of Lactobacillus casei protoplasts, the recombinants have been studied for their lactose utilization, protease activity and phage resistance. L. casei C-M phenotypes constituted 46% of the fused cells when tested against phages, and L. casei 3-M phenotypes 42% of the fused cells, and 12% of the recombinants developed the resistance to both parent types of phages. The acid production and proteolytic activity of recombinants evidenced the similar trends. There was no difference in Hind III digests of plasmid DNA between parent cells and recombinants, but the reconlbinant cells were found to possess only one type of plasmid, either of 1. casei C-M or of L. casei 3-M.

• International Journal of Industrial Entomology and Biomaterials
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• v.3 no.1
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• pp.13-18
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• 2001

The role of polyhedrin in the polyhedra production in baculovirus Autograha californica Nucelopolyhedro-sisvirus (AcNPV) was studied by over-expression of AcNPV polyhedrin or heterologous polyhedrin from Bombyx mori (Bm) NPV or Spodoptera exigua (Se) NPV. The transfer vectors containing additional polyhedrin from AcNPV, BmNPV, or SeNPV were constructed and cotransfected with bacmid bApGOZA into Sf9 cells. The resulting recombinants, designated as vApAcPol, vApBmPol, and vApSePol were tonstructed, and the polyhedra production of the recombinant was characterized. All of the recombinants produced polyhedra in the nucleus, and the polyhedrin was over-expressed. Among three recombinants, vApAcPol and vApBmPol were discriminated by their larger polyhedra size than that of wild type AcNPV, and vApSePol also produced larger polyhedra than wild type SeNPV polyhedra.

• Molecules and Cells
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• v.21 no.2
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• pp.302-307
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• 2006

Two Epstein-Barr virus (EBV) types, type 1 and type 2, maintain the same allelic specificity at four genomic loci encoding the EBNA2, -3A, -3B, and -3C proteins. We have previously described 16 EBV-transformed B-lymphoblastoid cell lines derived from Korean cancer patients, and the EBNA2 types of the EBV isolates therein. In this study, the allelic types of the EBNA2, -3A, -3B, and -3C genes of these EBV isolates were determined. We report the identification of two distinct types of naturally occurring intertypic recombinants, one with genotype EBNA2 type1/EBN3A, -3B, -3C type 2 and the other with genotype EBNA2, -3A type 1/EBNA3B, -3C type 2. The existence of these intertypic recombinants indicates that various intertypic EBV strains may be circulating in the human population, in addition to typical EBV-1 and EBV-2 strains.

• Journal of fish pathology
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• v.8 no.1
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• pp.31-36
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• 1995

Hc nuclear polyhedrosis virus DNA genome was digested with EcoRI endonuclease, these partial fragments were recombined into the pUC8 plasmid vector and transformed in E. coli JM 83 cell. The genome DNA has 24 EcoRI fragments and 12 fragments of them were subcloned. The four recombinants were named as eNP-O, eNP-Q, eNP-R and eNP-S. The expression of foregin gene of the recombinants was investigated by analysing protein patterns on the SDS-PAGE. The eNP-O, eNP-Q and eNP-R were expressed a different weight of protein as comparision with potypeptide bands of E. coli JM 83 host cell.

• Korean Journal of Microbiology
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• v.31 no.4
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• pp.318-325
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• 1993

The optima] conditions for the formation, the regeneration. and the spheroplast fusion of Flavimonas aryz/habitans spheroplasts were investigated. Cells were transformed to spherop]asts effectively by treatment of 0.5% volume (v/v) of 0.] M EDTA and ]00 flg/ml lysozyme at $37^{\circ}C$ for 30 min without shaking. Magnesium chloride and calcium chloride were effective on the stabilization of spheroplasts. and 20 mM calcium chloride in the rich regeneration medium improve the yield of regenerants as much as 3.5-fo]d. Addition of 0.8% bovine serium albumine (BSA) in dilution buffer for spheroplast formation improved the stabilization of spheroplasts over extended periods (4-6 hr) at room temperature. and thus increased the yield of recombinants to 4.5-fold. The spheroplast formation frequency and regeneration frequency of F aryzihabitans strain was 90.10% and 3.800/." respectively. The first regenerated cell of F. aryzihabitans spheroplasts were appeared 6 hours after plating. By I I hours after plating, 80% of spheroplasts were regenerated on thc rich regeneration medium containing 0.5 M sucrose. The intraspeci11c spheroplast fusion of F urvz/habitans was carried out and the properties of obtained fusants were investigated. Formation of fusion products was effective when the Flav/munas spheroplast mixture was treated with 40%(w/v) PEG6000 and 20 mM CaCl, for 10 min at room temperature. and thc formation of frequency of recombinants were $2.0{\times}10^{-5}~3.6{\times}10^{-5}$. All tested recombinant clones were very stable on further propagation.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.4
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• pp.587-596
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• 2001

In the last decade, rapid developments in molecular biotechnology and of genomic tools have enabled the creation of dense linkage maps across whole genomes of human, plant and animals. Successful development and implementation of interval mapping methodologies have allowed detection of the quantitative trait loci (QTL) responsible for economically important traits in experimental and commercial livestock populations. The candidate gene approach can be used in any general population with the availability of a large resource of candidate genes from the human or rodent genomes using comparative maps, and the validated candidate genes can be directly applied to commercial breeds. For the QTL detected from primary genome scans, two incipient fine mapping approaches are applied by generating new recombinants over several generations or utilizing historical recombinants with identity-by-descent (IBD) and linkage disequilibrium (LD) mapping. The high resolution definition of QTL position from fine mapping will allow the more efficient implementation of breeding programs such as marker-assisted selection (MAS) or marker-assisted introgression (MAI), and will provide a route toward cloning the QTL.

• Korean Journal of Veterinary Research
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• v.59 no.2
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• pp.89-96
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• 2019

Enterovirus species G (EV-G) is highly diverse, and is ubiquitous in pig populations, usually without diarrhea. The present study aimed to investigate the presence of novel EV-G recombinants with the torovirus papain-like cysteine protease (PLCP) in Jeju pig herds. EV-G1-PLCP mono-infections were most prevalent in diarrheic weaned piglets. The PLCP genes of the Jeju isolates varied in size and junction sequences, and were greatly heterogeneous, with 77.0-90.7% homology amongst all recombinants. Our results suggest that the exogenous PLCP gene has undergone continuous rapid mutation in the individual EV-G genomes following cross-order recombination, thereby causing clinical disease in swine.

• Journal of Microbiology and Biotechnology
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• v.28 no.9
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• pp.1482-1492
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• 2018

Fusarium oxysporum trypsin (FOT) is a fungal serine protease similar to mammal trypsin. The FOT could be successfully expressed in Pichiapastoris by engineering the natural propeptide APQEIPN. In this study, we constructed two recombinant enzymes with engineered amino acid sequences added to the N-terminus of FOT and expressed in P. pastoris. The N-terminal residues had various effects on the structural and functional properties of trypsin. The FOT, and the recombinants TE (with peptide YVEF) and TS (with peptide YV) displayed the same optimum temperature ($40^{\circ}C$) and pH (8.0). However, the combinants TE and TS showed significantly increased thermal stability at $40^{\circ}C$ and $50^{\circ}C$. Moreover, the combinants TE and TS also showed enhanced tolerance of alkaline pH conditions. Compared with those of wild-type FOT, the intramolecular hydrogen bonds and the cation ${\pi}$-interactions of the recombinants TE and TS were significantly increased. The recombinants TE and TS also had significantly increased catalytic efficiencies (referring to the specificity constant, $k_{cat}/K_m$), 1.75-fold and 1.23-fold than wild-type FOT. In silico modeling analysis uncovered that the introduction of the peptides YVEF and YV resulted in shorter distances between the substrate binding pocket (D174, G198, and G208) and catalytic triad (His42, Asp102, and Ser180), which would improve the electron transfer rate and catalytic efficiency. In addition, N-terminal residues modification described here may be a useful approach for improving the catalytic efficiencies and characteristics of other target enzymes.