• Current Research on Agriculture and Life Sciences
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• 제11권
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• pp.81-89
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• 1993

xylA 유전자의 발현에 관한 xylR 유전자의 조절 메카니즘을 밝히기 위한 연구의 일환으로 xylA 프로모터 하류에 cat 유전자를 삽입시켜 Pxyl-cat-xylA 융합 플라스미드인 pEXC131을 제작하였고 이 플라스미드를 xylA 변이주인DH77로 형질전환시킨 결과 xylose의 유도시에만 Cm 내성과 xylose isomerase활성이 나타났다. pEXC1131/DH77에 NTG를 처리하여 xylose 유도없이도 Cm 내성과 xylose isomerase의 활성을 나타내는 xylA 유전자의 구성적 변이주인 pEXC131-39를 xylR 변이주인 DH60으로 형질전환시킨 균주가 xylose에 의한 유도와 무관하게 Cm 내성 및 xylose isomerase 활성을 가지는 것으로 보아 xylA 유전자의 프로모터부위의 변이에 의한 구성적 변이주임을 확인하였다.

• 동아시아식생활학회지
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• 제7권4호
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• pp.527-537
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• 1997

This study was performed to determine the effects of antimutagenicity of Porturaca oleracea L. in Korea. In Ames test, the ethanol extract of Poturaca oleracea L. inhibited mutagenic activity of N-methyl-N'-nitro-N-nitrosoguanidine(MNNG), , 4-nitroquinoline-1-oxide(4NQO), benzo($\alpha$)pyrene (B($\alpha$)P) and 3-amino-1,4-dimethyl-5H-pyrido-(4,3-b)indole (Trp-P-1) in Salmonella typhimurium TA98 and TA100. But hot-water extract Poturaca oleracea L. only Inhibited mutagenic activity of MNNG in Salmonella typhimurium TA100, On 4NQO, the ethanol extract 100-1,600$\mu\textrm{g}$/plate of Porturaca oleracea L. showed a slight inhibitory effect of 13-48%, 4-47% in TA98 and TA100, respectively, but on MNNG, it showed higher inhibitory effect of 6-86% in TA100, And the treatment of 1,600$\mu\textrm{g}$/plate of ethanol extract of Porturacea L. had strong antimutagenicity with 74-87% inhibition against TA98 and TA100 induced by B(a)P and with 85-93% inhibition against TA98 and TA100 induced by Trp-P-1. The ethanol extract was fractionated with ether. chloroform, ethylacetate, butanol and water. Among them, most of the fraction except water fraction showed strong antimutagenicity effects against mutation induced by 4-NQO, MNNG, B(a)P and Trp-P-1. Chloroform fraction had strong antimutagenicity with 91% inhibition against TA100 induced by MNNG, diethyl etherfraction had strong antimutagenicity with 92%, 98% inhibition against TA98 and TA100 induced by 4NQO, Chloroform fraction had strong antimutagenicity with 97% inhibition against TA100 induced by B (a)P and diethyl etherfraction had strong antimutagenicity with 98% inhibition against both strain Induced by Trp-P-1, respectively.

• 한국초지조사료학회지
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• 제15권1호
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• pp.1-12
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• 1995

This study was to investigate an effective biological control of forage diseases and provide a basic data and a model in improving variety of antagonistic bacteria, with growth promoting effect on forage, through cell fusion. The results obtained were summarized as follows; 1. The antagonistic himbacterium against soil-borne phathogenic fungi Fusarium oxysporum and Rhizoctonia solani was isolated from continuous cropping himsphere soil of forage, and its biological and physiological characteristics were investigated. This bacterium was identified as Bacillus subrilis and named BS 101. Another strain for cell fusion was Bacillus thur ingiensis ssp. kurstaki HD-I(BT 37669) with insecticidal crystal. 2. The auxotropic mutants of BS 101 and BT 37669 were derived after mutagenesis using N-methyl-N'nitro- Nitrosoguanidine(NTG) to give amino acid requirement marker. n e s e auxotropic mutants of BS 101 and BT 37669 were named BS 1013(his-) and BT 69(asp-), respectively. 3. The best protoplast requirement was obtained using DM 3 medium, containing 5% casamino acid, 1 M $MgCI_2$ and 2% bovine semm albumin, to give Fusant 3, 7 and 8. BT toxin gene was not identified with fusants by Southern blotting. However, SDS-PAGE analysis of strains showed various protein patterns among fusants. 4. From the dark culture experiment, growth of forage in inoculated soil with antagonistic bacteria was delayed than that of non-inoculated soil with antagonistic bacteria in each continuous cropping soil and in each sterilized soil. On the other hand, growth duration of forage was different between continuous cropping soil and sterilized soil. 5. Seed germination of Alfalfa, Italian ryegrass and Orchardgrass were significantly improved by inoculation of antagonistic bacteria(p< 0.05).

• 한국식품과학회지
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• 제30권2호
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• pp.450-455
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• 1998

한국에 널리 분포하고 있는 곰솔, 리기다, 잣나무, 적송의 에탄올추출물과 각 용매 분획물을 이용하여, in vitro assay로서 spore rec-assay와 Salmonella typhimurium reversion assay법으로 시료자체 변이원성 유무와 4가지 양성변이원 물질(MNNG, 4NQO, Trp-P-1 및 B(a)p)에 대한 돌연변이 억제효과를 고찰하였다. 곰솔, 리기다, 잣나무, 적송의 에탄올 추출물은 spore rec-assay와 S. typhimurium를 이용한 mutagenicity assay에서 변이원성을 나타내지 않았다. 돌연변이 억제 시험에서는 4가지 시료 모두 농도 증가에 따른 억제율을 나타내었고 또 각각의 시료들의 분획물 중 잣나무와 소나무의 에테르 분획물들이 간접변이원인 Trp-P-1의 변이원성에 대하여 다른 분획물에 비하여 높은 억제율을 보여주었다.

• Journal of Microbiology and Biotechnology
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• 제26권9호
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• pp.1570-1578
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• 2016

Commercial application of laccase is often hampered by insufficient enzyme stocks, with very low yields obtained from natural sources. This study aimed to improve laccase production by mutation of a Coriolopsis gallica strain and to determine the biological properties of the mutant. The high-yield laccase strain C. gallica TCK was treated with N-methyl-N-nitro-N-nitrosoguanidine and ultraviolet light. Among the mutants isolated, T906 was found to be a high-production strain of laccases. The mutant strain T906 was stabilized via dozens of passages, and the selected ones were further processed for optimization of metallic ion, inducers, and nutritional requirements, which resulted in the optimized liquid fermentation medium MF9. The incubation temperature and pH were optimized to be 30℃ and 4.5, respectively. The mutant strain T906 showed 3-times higher laccase activity than the original strain TCK under optimized conditions, and the maximum laccase production (303 U/ml) was accomplished after 13 days. The extracellular laccase isoenzyme 1 was purified and characterized from the two strains, respectively, and their cDNA sequence was determined. Of note, the laccase isoenzyme 1 transcription levels were overtly increased in T906 mycelia compared with values obtained for strain TCK. These findings provide a basis for C. gallica modification for the production of high laccase amounts.

• 한국미생물·생명공학회지
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• 제30권2호
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• pp.111-115
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• 2002

천연 황색소 생산을 위하여 Monascus anka Nakazawa et Sato IFO 4478(KCCM l1832 strain) 균주를 모균주로 하여 UV 조사 및 NTG(N-methyl-N'-nitro-N-nitrosoguanidine)처리 및 이들 방법을 병용하는 방법을 사용하여 모균주와는 색소생성 특성이 다르게 황색소를 단일성분으로 생성하는 변이주를 분리하고 그 특성을 조사하였다. leucine, cystein, aspartic acid, glutamic acid 와 asparagine 등 5종의 아미노산에 대한 영양요구주를 분리하였고 이중 asparagine 영양요구주 Y7은 colony 형태와 균사의 직경에서 약간의 차이를 나타내지만 전형적인 Monascus 균주의 특성을 지니고 있었으며 특히 유성생식에 의한 번식 특성이 강하여 색소 생성에 유리한 조건을 지니고 있었다. 그리고 Y7은 밝은 색조의 황색소를 단일 성분으로 생성하며 10대 이상의 계대배양에서도 색소 생성 특성이 안정하였고 색소 생성량이 모균주보다 약 2.2배 높은 값을 나타내고 있었다. 이때 생성된 황색소는 373 nm에서 단일 흡수 peak를 나타내고 물, 에탄올 등 극성용매에 대한 용해성이 높은 특성을 나타내며 생성된 색소의 대부분이 균체 밖으로 배출되는 특성을 지니고 있었다.

• 한국식품과학회지
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• 제31권4호
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• pp.1071-1076
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• 1999

본 연구에서는 김치발효에 관여하는 우세 발효균들의 집락을 분리하고, 발암원인 MNNG에 대하여 이들 분리주들이 갖는 DNA 손상 억제효과를 조사하였다. 이를 위해서 세포의 DNA 손상 및 복구를 측정하는데 이용되는 매우 신속하고 감도가 높은 Single Cell Gel Electrophoresis(SCGE 법, 또는 comet assay)를 사용하였다. 배추김치에서 분리한 3개의 분리주중에서 B-3를 제외한 B-1과 B-2는 양성 대조구와 비교하였을 때 우수한 항유전 독성효과를 나타내었으며(p<0.01), 율무김치의 3 개의 분리주(Y-1, Y-2, Y-3)와 1개의 분리주(Y-4)도 각각 항유전 독성효과를 나타내었다(p<0.05, p<0.01). 총각김치의 5 개 분리주중에서 3개의 분리주와 깍두기의 9개의 분리주중에서 2 개의 분리주들도 각각 항유전 독성효과를 나타내었다(p<0.05, p<0.01).

• Toxicological Research
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• 제20권3호
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• pp.225-232
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• 2004

The suitability of the single cell gel electrophoresis (SCGE) assay as a test for the monitoring of genotoxicity of aquatic environment was evaluated. The SCGE assay was employed to detect DNA damage induced in clam (Spisula sachalinensis) exposed to a direct mutagen, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) or an indirect mutagen, benzo[a]pyrene (B[a]P). The cells of gill and digestive glands were isolated from clam by homogenization, which was the optimized cell dissociation method, and the level of DNA damage was assessed and expressed as mean tail length. In the gill cells, significant dose- and time-dependent increase was observed in the mean tail length at the concentration from 0.01 to 0.5 ppm MNNG for 96 h. The linear correlation between relative dam-age index (RDI) values was suggested to provide criteria of genotoxicity monitoring for direct acting mutagen. The dose- and time-dependent responses of the digestive glands cells were less sensitive than those of the gill cells. In contrast, the genotoxic response resulting from the exposure of 0.01～1.0 ppm B[a]P to clam revealed a higher sensitivity in the digestive glands cells than the gill cells. The comparison between the time profiles of genotoxic responses in clam and carp, the latter had been obtained in our previous study, indicated that the metabolism of genotoxic compounds in the two aquatic organisms were quite different each other. We conclude that the SCGE assay has the potential as a screening test for routine genotoxicity monitoring of aquatic organisms because of its higher sensitivity and simplicity.

• Archives of Pharmacal Research
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• 제25권3호
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• pp.293-299
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• 2002

Cytotoxic and antimutagenic effects of a novel cis-$\varepsilon$-viniferin and five known stilbenes, transresveratrol, trans-$\varepsilon$-viniferin, gnetin H, suffruticosols A and B, isolated from the seeds of Paeonia lactiflora Pall. (Paeoniaceae) were determined against five different cancer cell lines, and mutagenicity of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in Salmonella typhimurium TA100, respectively. Six stilbenes showed cytotoxic activity in a dose-dependent manner, and especially did potent cytotoxic activity against C6 (mouse glioma) cancer cell with $IC_{50}$ values ranging from 8.2 to $20.5{\;}{\mu\textrm{g}}/ml$. trans-Resveratrol showed significant cytotoxic activity against HepG2 (liver hepatoma) and HT-29 (colon) human cancer cell lines with $IC_{50}$ values of 11.8 and 25.2 g/ml, respectively. In contrast, trans-$\varepsilon$-viniferin and cis--viniferin, and gnetin H exhibited marked cytotoxic activity against Hela (cervicse) and MCF-7 (breast) human cancer cell lines with $IC_{50}$ values of 20.4, 21.5, and $12.9{\;}{\mu\textrm{g}}/ml$, respectively. However, suffruticosol A and B had less cytotoxic effect against all cancer cells except C6. Meanwhile, six stilbenes exerted antimutagenic activity in a dose-dependent fashion. Of them, trans-resveratrol exhibited the strongest antimutagenic effect against MNNG with $IC_{50}$ value of $27.0{\;}{\mu\textrm{g}}/plate$, while other five resveratrol oligomers also did moderate antimutagenic activity with $IC_{50}$ values ranging from 31.7 to $35.2{\;}{\mu\textrm{g}}/plate$.

• Asian Pacific Journal of Cancer Prevention
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• 제13권10호
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• pp.4897-4900
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• 2012

Objective: In this study, anticancer effects of mirtazapine on rats were investigated in an adenocarcinoma model induced by N-methyl-N-nitro-N-nitrosoguanidine (MNNG) and compared with those of cisplatin. Materials and Methods: For this purpose, 10 mg/kg doses of mirtazapine were administered orally to one group of rats, while 1 mg/kg doses of cisplatin were administered intraperitoneally to another group. At 1 hour after administration, 200 mg/kg doses of MNNG were given orally to both groups. MNNG administration was repeated once every 10 days through 3 months, after which period, gastric tissue was taken and pathologically evaluated. Results: Mirtazapine prevented adenocarcinoma induction by MNNG in rats to a greater extent than cisplatin. Some of the rats receiving cisplatin demonstrated severe dysplasia in gastric samples and others exhibited mild dysplasia. Rats given mirtazapine were not observed to suffer severe dysplasia, only mild dysplasia being observed. Conclusion: For adenocarcinoma induced by MNNG on rats, mirtazapine was determined more effective than cisplatin. In order to make statement about mechanism of anticancer activity of mirtazapine, wider studies are required.