• Korean Journal of Microbiology
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• v.27 no.1
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• pp.10-15
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• 1989

The plasmid pKOneo, containing SV40 transcriptional promoter, has been used in the mouse tumorigenicity assay for oncogene studies. This assay employs a cotransfection of NIG3T3 fibroblast cells with the desired DNA and the plasmid pKOneo. This oncogene assay, however, has been speculated due to the SV40 transcriptional promoter in the plasmid pKOneo. This research was designed to investigate if the plasmid pKOneo alone is capable of transforming NiH3T3 fibroblast cells. The NIH3T3 subclones were established after the NIH3T3 cells were transfected with the plasmid pKOneo alone. The estabilished NIH3T3 subclones, containing the exogeneous plasmid pKOneo in their chromosomes, were examined for their expression of transformation-associated parameters. The results indicate that this plasmid pKOneo alone has positive effects on transformation of NIH3T3 cells after integration into cellular chromosomes.

• Journal of Animal Science and Technology
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• v.46 no.2
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• pp.235-242
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• 2004

A system for the production of transgenic plants has been developed for Italian ryegrass(Lolium mult리orum Lam.) via Agrobacterium-mediated transformation of embryogenic callus. Mature seed-derived calli were infected and co-cultured with Agrobacterium EHA101 carrying standard binary vector pIG121Hm encoding the hygromycin phosphotransferase(HPT), neomycin phosphotransferase II (NPTII) and intron-oontaining $\beta$g1ucuronidase( intron-GUS) genes in the T-DNA region. The effects of several factors on transformation and the expression of the GUS gene were investigated. Inclusion of 200${\mu}M$ acetosyringone(AS) in inoculation and co-cultivation media lead to a significant increase in stable transformation efficiency. Increasing Agrobacterium cell density up to 1.0 in $OD_{600}$ during infection increased transfonnation efficiency of embryogenic calli. The highest transfonnation efficiency was obtained when embryogenic calli were incoulated with Agrobacterium in the presence of 0.1% Tween20 and 200${\mu}M$ AS. Hygromycin resistant calli were developed into complete plants via somatic embryogenesis. GUS histochemical assay and PCR analysis of transgenic plants demonstrated that transgenes were integrated into the genome of Italian ryegrass.

• Microbiology and Biotechnology Letters
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• v.11 no.1
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• pp.75-79
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• 1983

To exploit a suitable vector and recipient strain for molecular cloning in Bacillus subtilis, oxytetracycline-resistant plasmic DNA has been prepared from Streptomyces rimosus by phenol-buffer extraction of lysozyme-lysed cells and introduced into B. subtilis KPM 60 [St $r^{R}$-mutant of RM 125 (leu A8, arg 15, hsm $M^{-10}$ , hsr $M^{-10}$ )] by transformation. Oxitetracycline-resistant plasmid was well transferred into B. subtilis KPM 60 with average frequency of 10$^{-4}$ per $\mu\textrm{g}$ of DNA. The highest frequency of plasmid transformation was obtained after 3 hours incubation of recipient cells in the growth medium and 30 to 60 minutes incubation in the competence medium, and then 20 minutes contact of DNA and host cells. Optimum pH for competence was 7.5, and optimum temperature for transformation was 2$0^{\circ}C$.>.

• Journal of Sericultural and Entomological Science
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• v.52 no.1
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• pp.25-32
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• 2014

We produced the transgenic silkworm that expressed the enhanced blue fluorescent protein (EBFP) in the cocoon of silkworms. The EBFP fusion protein, each with N- and C-terminal sequences of the fibroin H-chain, was designed to be secreted into the lumen of the posterior silk glands. The expression of the EBFP/H-chain fusion gene was regulated by the fibroin H-chain promoter. The use of the $3{\times}P3$-driven DsRed2 cDNA as a marker allowed us to rapidly distinguish transgenic silkworm. A mixture of the donor and helper vector was micro-injected into 300 eggs of silkworms, Baegokjam. We obtained 5 broods. The cocoon displayed blue fluorescence, proving that the fusion protein was present in the cocoon. Also, the presence of fusion proteins in cocoons was demonstrated by SDS-PAGE and western blot analysis. Accordingly, we suggest that the EBFP fluorescence silk will enable the production of the silk-based biomaterials.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.2
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• pp.111-116
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• 1991

The effective p.eduction of 5'-GMP(5'-Guanylic acid) by enzymatic conversion of 5'-XMP(5'-Xanthyic acid) was investigated. The Iyophilized Brevibacterium ammoniagenes ATCC 19216 which were used as the XHP aminase source, was immobilized by entrapping in K-carrageenan, agar, polyacrylamide or Ca-alginate. $3\%$ K-carrageenan was selected as the most suitable matrix. In the production of 5'-GMP using the free cells of 3. ammoniagenes ATCC 19216, the optimum conditions were $42^{\circ}C$, PH 7.0, 100mg/ml glucose, 120mg/ml cell ,8mg/ml $MgSO_4\cdot7H_2O$, 5mg/ml POESA, 5mg/ml phytic acid. Under the conditions, $94.5\%$ of 5'-GMP was converted within 8 hours. In the production of 5'-GMP using the immobilized whole cells of B. ammoniagenes ATCC 19216, the optimum conditions were $37^{\circ}C$, pH 7.5, 50mg/ml glucose, 1mg/ml $KH_2PO_4$, 10mg/ml phytic acid, 60mg/ml cell, 8mg/ml $MgSO_4\;\cdot\;7H_2O$, 5mg/ml POESA. Under the conditions, $64.7\%$ of 5'-GMP was converted within 40 hours.

• Microbiology and Biotechnology Letters
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• v.17 no.3
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• pp.213-218
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• 1989

To investigate the possibility of using alkalophilic Bacillus sp. K-11 as a host for molecular cloning, plasmid pUB110 and pBD64 were introduced into alkalophilic Bacillus sp. K-17 by protoplast transformation system. Protoplasts of Bacillus sp. K-11 were prepared by treatment with 200 $\mu\textrm{g}$/$m\ell$ Iysozyme in SMM buffer containing 0.4M sucrose. Optimal temperature, pH and culture time for protoplast formation were 4$0^{\circ}C$, 7.0 and 4hrs, respectively. Cell wall was regenerated efficiently on DM3 medium containing 0.8% agar and 0.5M sodium succinate. Under these conditions for protoplast formation and regeneration, the highest transformation efficiency was obtained with cells incubated for 4hrs, and using 30%(V/V) of 40%(W/V) PEG6,000, In characteristics of transfer-mants, plasmid pUB110 was more stable than plasmid pBD64 in Bacillus sp. K-17. Maximum xylanase production of both transformants carrying pUB110 and pBD64, respectively was similar, but under the same conditions, enzyme secretion by transformant carrying pUB110 was earlier than that of transformant carrying pBD64.

• Microbiology and Biotechnology Letters
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• v.15 no.6
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• pp.441-445
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• 1987

The gene coding for alkaline amylase of alkalophilic Bacillus sp. AL-8 was cloned and expressed in Escherichia coli which was lack of amylase activity. For the cloning of the alkaline amylase gene, the chromosomal DNA and plasmid vector pBR322 were cleaved at the site of EcoRI and the gene was cloned. The selection of the transformants carrying the amylase gene was based on the their antibiotics resistance and amylase activity of the transformants. The recombinant plasmids pJW8 and pJW200 containing 5.8Kb and 3.0Kb EcoRI inserts respectively were proved to can the alkaline amylase gene. Alkaline amylase expressed in E. coli was characterized. The enzyme was proved to be stable at the range of alkaline pH.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.4
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• pp.41-50
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• 2017

The design of proper agitation system is requisite in biological waste treatment and energy generation plant, which is affected by viscosity, impeller types, and power consumption. In the present work, hydrogen fermentation of food waste was conducted at various operational pHs (4.5~6.5) and substrate concentrations (10~50 g Carbo. COD/L), and the viscosity of fermented broth was analyzed. The $H_2$ yield significantly varied from 0.51 to $1.77mol\;H_2/mol\;hexose_{added}$ depending on the pH value, where the highest performance was achieved at pH 5.5. The viscosity gradually dropped with shear rate increase, indicating a shear thinning property. With the disintegration of carbohydrate, the viscosity dropped after fermentation, but it did not change depending on the operational pH. At the same pH level, the $H_2$ yield was not affected much, ranging $1.40{\sim}1.86mol\;H_2/mol\;hexose_{added}$ at 10~50 g Carbo. COD/L. The zero viscosity and infinite viscosity of fermented broth increased with substrate concentrations, from 10.4 to $346.2mPa{\cdot}s$, and from 1.7 to $5.3mPa{\cdot}s$, respectively. There was little difference in the viscosity value of fermented broth at 10 and 20 g Carbo. COD/L. As a result of designing the agitation intensity based on the experimental results, it is expected that the agitation intensity can be reduced during hydrogen fermentation. The initial and final agitation intensity of 30 g Carbo. COD/L in hydrogen fermentation were 26.0 and 10.0 rpm, respectively. As fermentation went on, the viscosity gradually decreased, indicating that the power consumption for agitation of food waste can be reduced.

• Journal of KIISE
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• v.44 no.2
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• pp.132-138
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• 2017

We design and implement a process-based fault recovery system to increase the reliability of new memory based computer systems. A rollback point is made at every context switch to which a process can rollback to upon a fault. In this study, a clone process of the original process, which we refer to as a P-process (Persistent-process), is created as a rollback point. Such a design minimizes losses when a fault does occur. Specifically, first, execution loss can be minimized as rollback points are created only at context switches, which bounds the lost execution. Second, as we make use of the COW (Copy-On-Write）mechanism, only those parts of the process memory state that are modified (in page units) are copied decreasing the overhead for creating the P-process. Our experimental results show that the overhead is approximately 5% in 8 out of 11 PARSEC benchmark workloads when P-process is created at every context switch time. Even for workloads that result in considerable overhead, we show that this overhead can be reduced by increasing the P-process generation interval.

• KSBB Journal
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• v.10 no.1
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• pp.9-14
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• 1995

Continuous production of fructooligosaccharides from sucrose by a dual immobilized enzyme system of fructosyltransferase and glucose isomerase was studied in a column reactor. The optimal temperature and pH of the immobilized fructosyltransferase were $65^{\circ}C$ and 5.5, respectively. The activity of glucose isomerase was favorable as temperature and pH were increased within the ranges examined. However, both the immobilized enzymes were thermally unstable over $5^{\circ}C$, suggesting that long-term operation of the dual immobilized enzyme column should be carried out below $50^{\circ}C$. The optimum packing ratio of fructosyltransferase to glucose isomerase was found to be around 5/3. Under the optimized reaction conditions, the dual enzyme column was successfully operated for 40 days without any loss of initial enzyme activities, yielding 66% of fructooligosaccharides. Furthermore, the relative sweetness of fructooligosaccharides produced by a dual emzyme system was enhanced by 6% compared with that of fructosyltransferase alone.