• 대한바이러스학회지
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• 제27권2호
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• pp.143-149
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• 1997

Most of the current licenced hepatitis B vaccines are being produced by recombinant DNA technology in large fermentation cultures of Saccharomyces cerevisiae of yeast cells which carry the gene coded for hepatitis B virus surface antigen. These vaccines are proved very effective clinically and the immunogenicity of vaccines could be maintained for a long time under refrigeration. To develope the stabilizer that could increase the stability of hepatitis B virus vaccine which could be stored for a long period at room temperature or higher conditions, glucose, lactose and sucrose solutions in phosphate buffered saline were added into hepatitis B vaccine respectively to make 2.5%, 5%, 7.5% and 10% final concentration in vaccines. These sugar-vaccine mixtures were stored at room temperature for one month, two months and three months respectively and then inoculated into ICR mice intramuscularly. On the fourteenth day after inoculation, mice were bled and sera were tested for the evaluation of efficacies of vaccines. The results showed that 5% glucose, 7.5% lactose and sucrose increased the stability of vaccines in some degree and this method could be applied for the production of other viral vaccines and bacterial vaccines.

• Preventive Nutrition and Food Science
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• 제9권4호
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• pp.324-329
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• 2004

In order to investigate the molecular mechanism of $\gamma$-aminobutyric acid (GABA) production in lactic acid bacteria, we cloned a glutamate decarboxylase (GAD) gene from Lactobacillus plantarum using polymerase chain reaction (PCR). One PCR product DNA was obtained and inserted into a TA cloning vector with a T7 promoter. The recombinant plasmid was used to transform E. coli. The insertion of the product was con­firmed by EcoRI digestion of the plasmid purified from the transformed E. coli. Nucleotide sequence analysis showed that the insert is a full-length Lactobacillus plantarum GAD and that the sequence is $100\%$ and $72\%$ identical to the regions of Lactobacillus plantarum GAD and Lactococcus lactis GAD sequences deposited in GenBank, accession nos: NP786643 and NP267446, respectively. The amino acid sequence deduced from the cloned Lactobacillus plantarum GAD gene showed $100\%$ and $68\%$ identities to the GAD sequences deduced from the genes of the NP786643 and NP267446, respectively. To express the GAD protein in E. coli, an expression vector with the GAD gene (pkk/GAD) was constructed and used to transform the UT481 E. coli strain and the expression was confirmed by analyzing the enzyme activity. The Lactobacillus plantarum GAD gene obtained may facilitate the study of the molecular mechanisms regulating GABA metabolism in lactic acid bacteria.

• Journal of Microbiology and Biotechnology
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• 제7권1호
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• pp.8-12
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• 1997

In order to overproduce D-xylose isomerase, the Escherichia coli D-xylose isomerase (D-xylose ketol-isomerase, EC 5.3.1.5) gene (xylA) was fused to ${\lambda}P_{L}$ promoter. The promoterless xylA gene containing the ribosome binding site and coding region for D-xylose isomerase was cloned into a site 0.3 kb downstream from the ${\lambda}P_{L}$ promoter on a high copy number plasmid. An octameric XbaI linker containing TAG amber codon was inserted between 33rd codon of ${\lambda}N$ and the promoterless xylA gene. The resulting recombinant plasmid (designated as pPX152) was transformed into E. coli M5248 carrying a single copy of the temperature sensitive ${\lambda}cI857$ gene on its chromosomal DNA. When temperature-induced, the transformants produced 15 times as much D-xylose isomerase as that of D-xylose-induced parent strain. The amount of overproduced D-xylose isomerase was found to be about 60% of total protein in cell-free extracts.

• Journal of Plant Biotechnology
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• 제5권2호
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• pp.69-77
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• 2003

The ornamental industry encompasses cut flower, pot plant, turfgrass and nursery stock production and is an important part of the agricultural sector. As internationally traded commodities, cut flowers and plants are an integral part of the economy of a number of developing countries in South America, the Caribbean and Africa. Genetic modification (GM) is a tool with great potential to the ornamental horticulture industry. The rapid progress in our knowledge of plant molecular biology can accelerate the breeding ornamental plants using recombinant DNA technology techniques. Not only is there the possibility of creating new, novel products the driver of the industry but also the potential to develop varieties requiring less chemical and energy inputs. As an important non-food agricultural sector the use of genetically modified (GM) ornamental crops may also be ideal for the intensive farming necessary to generate pharmaceuticals and other useful products in GM plants. To date, there are only a few ornamental GM products in development and only one, a carnation genetically modified for flower colour, in the marketplace. International Flower Developments, a joint venture between Florigene Ltd. in Australia and Suntory Ltd. of Japan, developed the GM carnations. These flowers are currently on sale in USA, Japan and Australia. The research, development and commercialization of these products are summarized. The long term prospects for ornamental GM products, like food crops, will be determined by the regulatory environment, and the acceptance of GM products in the marketplace. These critical factors will be analysed in the context of the current legislative environment, and likely public and industry opinion towards ornamental genetically modified organisms (GMO's).

• Journal of Plant Biotechnology
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• 제29권3호
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• pp.199-207
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• 2002

The tropane alkaloids hyoscyamine (its racemic form being atropine) and scopolamine are used medicinally as anticholinergic agents that act on the parasympathetic nerve system. Because they differ in their actions on the central nervous system, currently there is a 10-fold higher commercial demand for scopolamine, in the N-butylbromide form, than there is for hyoscyamine and atropine combined. Several solanaceous species have been used as the commercial sources of these alkaloids, but the scopolamine contents in these plants often are much lower than those of hyoscyamine. For this reason there has been long-standing interest in increasing the scopolamine contents of cultivated medicinal plants. Naturally occurring and artificial interspecific hybrids of Duboisia have high scopolamine contents and are cultivated as a commercial source of scopolamine in Australia and other countries. Anther culture combined with conventional interspecific hybridization also has been used to breed high scopolamine-containing plants in the genera Datura and Hyoscyamus, but without much success. The use of recombinant DNA technology for the manipulation of metabolic processes in cells promises to provide important contributions to basic science, agriculture, and medicine. In this review, I introduce on the enzymes and genes involved in tropane alkaloid biosynthesis and current progress in metabolic engineering approaches for tropane alkaloid, especially scopolamine, production.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2003년도 식물바이오벤처 페스티발
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• pp.39-48
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• 2003

The ornamental industry encompasses cut flower, pot plant, turfgrass and nursery stock production and is an important part of the agricultural sector. As internationally traded commodities, cut flowers and plants are an integral part of the economy of a number of developing countries in South America, the Caribbean and Africa. Genetic modification (GM) is a tool with great potential to the ornamental horticulture industry. The rapid progress in our knowledge of plant molecular biology can accelerate the breeding ornamental plants using recombinant DNA technology techniques. Not only is there the possibility of creating new, novel products the driver of the industry but also the potential to develop varieties requiring less chemical and energy inputs. As an important non-food agricultural sector the use of genetically modified (GM) ornamental crops may also be ideal for the intensive farming necessary to generate pharmaceuticals and other useful products in GM plants. To date, there are only a few ornamental GM products in development and only one, a carnation genetically modified for flower colour, in the marketplace. International Flower Developments, a joint venture between Florigene Ltd. in Australia and Suntory Ltd.of Japan, developed the GM carnations. These flowers are currently on sale in USA, Japan and Australia. The research, development and commercialisation of these products are summarised. The long term prospects for ornamental GM products, like food crops, will be determined by the regulatory environment, and the acceptance of GM products in the marketplace. These critical factors will be analysed in the context of the current legislative environment, and likely public and industry opinion towards ornamental genetically modified organisms (GMO's).

• 미생물학회지
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• 제39권3호
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• pp.128-134
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• 2003

Transformation-associated recombination (TAR) 클로닝법은 목적 유전자를 포함한 게놈 DNA와 그 유전자의 5' 또는 3' 말단 서열을 포함하고 있는 선형의 TAR vector를 동시에 출아효모의 spheroplast내로 co-penetration 시켜 상동부위에서 일어나는 재조합에 의해 환형의 Yeast Artification Chromosome(YAC)으로 분리되는 방법이다. 일반적으로 TAR 클로닝법에 의한 목적의 single-copy 유전자 분리 빈도는 전체 형질전환체의 0.01~1% 정도이다. 이러한 TAR 클로닝법을 개선하기 위하여 Tg.AC transgenic mouse를 모델계로 사용하여 유전자 분리에 대한 target hook 내의 GC content 가 미치는 영향을 조사하였다. 이러한 목적으로 한쪽에는 다양한 GC content(18~45%)를 지닌 transgene 특이적 hook을 포함하고 다른 한쪽은 B1 반복서열을 가지는 radial TAR vector를 사용하여 transgene 분리 빈도를 측정하였다. 그 결과 target hook의 GC content는 23% 이하의 경우, ~40%인 경우에 비해 두 배 정도 클로닝 빈도가 감소하였다. 따라서 TAR vector를 제작할 때, 유전자 분리에 이용되는 target hook의 GC content는 약 40% 일때 가장 적정한 것으로 나타났다. 또한 높은 target hook 내의 GC content(65%)위치분포에 의한 차이는 클로닝 빈도에 큰 영향을 미치지 않는 것으로 나타났다.

• Preventive Nutrition and Food Science
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• 제5권3호
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• pp.153-159
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• 2000

A 4.4 kb DNA fragment encompassing lacA (galactoside acetyltransferase) and lacZ($\beta$-galactosidase) genes from Lactococus lactis ssp. lactis ATCC 7962 (L. lactis 7962) was introduced ito a Lac strain, Lactococcus lactis ssp. lactis MG1363 (L. lactis MG1363) by using a lactococcal expression vector, pMG36e and expression level of lacZ was examined. Growth rates and $\beta$-galactosidase ($\beta$-gal) activities of MG1363 cells carrying recombinant plasmid, pMLZ3, on M17 broth containing different carbon sources (1%, w/v) were examined. Contrary to the expectations, MG1363 [pMLZ3] grown on lactose showed the lowest enzyme activity (17 units) and cells grown on galactose had the highest $\beta$-gal activity (41 units). Cells grown on glucose had intermediate activity (33 units). These activities are about one tenth of the values observed in L. lactis 7962 where lacZ is present as a single-copy gene in the chromosome. When the cellular concentrations of lacZ transcript were examined using slot blot hybridization, it was found that MG1363[pMLZ3] produced sufficient amounts of transcript. These results indicate that either proteolytic degradation of $\beta$-gal or other regulatory mechanism prevent the translation or accumulation of $\beta$-gal in L. lactis MG1363 cells. In regard to regulation, the presence of the ccpA gene in L. lactis MG1363 was confirmed by Southern blot.

• Journal of Plant Biotechnology
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• 제40권1호
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• pp.1-8
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• 2013

감자는 벼, 보리, 밀과 함께 세계 4 대 식량작물에 속하며 고품질의 전분과 함께 비타민 C 함량이 높고 단백질의 함량도 높다. 그러나 메티오닌과 시스테인 등의 황 함유 아미노산과 함께 필수아미노산이 부족하여 영양학적으로 가치가 다소 낮다는 것이 단점이다. 따라서 최근에는 유전자재조합 기술 및 대사공학기술을 이용하여 이들 필수아미노산의 함량을 증대시키기 위한 연구가 활발히 진행되고 있다. 본 논문에서는 황 함유 필수 아미노산의 함량을 증가시키기 위한 연구현황 및 문제점 등을 조사하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제12권1호
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• pp.84-92
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• 1999

The rumen microbial ecosystem is coming to be recognized as a rich alternative source of genes for industrially useful enzymes. Recent advances in biotechnology are enabling development of novel strategies for effective delivery and enhancement of these gene products. One particularly promising avenue for industrial application of rumen enzymes is as feed supplements for nonruminant and ruminant animal diets. Increasing competition in the livestock industry has forced producers to cut costs by adopting new technologies aimed at increasing production efficiency. Cellulases, xylanases, ${\beta}$-glucanases, pectinases, and phytases have been shown to increase the efficiency of feedstuff utilization (e.g., degradation of cellulose, xylan and ${\beta}$-glucan) and to decrease pollutants (e.g., phytic acid). These enzymes enhance the availability of feed components to the animal and eliminate some of their naturally occurring antinutritional effects. In the past, the cost and inconvenience of enzyme production and delivery has hampered widespread application of this promising technology. Over the last decade, however, advances in recombinant DNA technology have significantly improved microbial production systems. Novel strategies for delivery and enhancement of genes and gene products from the rumen include expression of seed proteins, oleosin proteins in canola and transgenic animals secreting digestive enzymes from the pancreas. Thus, the biotechnological framework is in place to achieve substantial improvements in animal production through enzyme supplementation. On the other hand, the rumen ecosystem provides ongoing enrichment and natural selection of microbes adapted to specific conditions, and represents a virtually untapped resource of novel products such as enzymes, detoxificants and antibiotics.