• Korean Journal of Microbiology
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• v.17 no.3
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• pp.137-151
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• 1979

Germinating conidia of Aspergillus nidulans diploid heterozygous for color and other genetic markers were used to direct and distinguish genetic events such as mutation, mitotic crossingover and nondisjunction in a single test after treatment with N-methyl-N'-nitro-N-nitrosoguanidine (NG), mitomycin C(MC), and chloral hydrate(CH). The following results were obtained : 1. NG reduced the survival of conidia and increased the frequencies of miototic segregants about sevenfoli over the control ; among the mitotic segregants the predominant genetic event was mitotic crossingover. NG also produced many abnormal colonies, which appeared to be of the types caused by induced semidominant lethals or chromosomal aberrations, and the aneuploid types found spontaneously. 2. After treatment with MC the survival of conidia was reduced but few abnormal colonies were produced. The frequencies of miotic segregants were increased about threefold over the control ; in the mitotic segeregants the induced genetic event was mitotic crossingover. 3. CH gave no apparent effect on the survival of conidia and the frequencies of mitotic segregants. However, CH generated abnormal colonies, very greatly, which turned out to be of the aneuploid types. This result suggests that CH interferes with the normal distribution of chromosomes in mitosis.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.715-718
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• 2000

The character of a recombinant bioluminescent bacteria's light emission enables us to monitor toxicity in water, soil and air. In this study, various bioluminescent responses to water samples containing toxic chemicals, such as phenol and mitomycin C, were obtained and analysed through the use of a multi-channel two-stage minibioreactor system. The bioluminescent pattern from each channel can be used as a standard for identifying the degree of toxicity in field samples. When various concentrations of toxic chemicals were injected in a step manner, different bioluminescent patterns were obtained. Also this system showed variation in its bioluminescent pattern as the injection manner was changed, i.e. using a modified version of the bell-curve type injection. In conclusion, the toxicity was shown to be related with the bioluminescent response when using these standard bioluminescent patterns. Comparing this standard with a bioluminescent response from a field sample, we can estimate the degree of which the sample is toxic.

• Archives of Pharmacal Research
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• v.15 no.1
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• pp.35-40
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• 1992

S. fradiae showed the highest acetanilide p-hydroxylation activity in the tested strains. And S. fradiae was well characterized genetically, especially with respect to tylosin production. Two mutants, which lost hydroxylation, were isolated in 140 regenerated colonies from protoplasts. In restriction enzyme digesion of total DNAs, isolation of giant linear plasmid DNA and determination of antibiotic resistances to chloramphenicol, tylosin, hygromycin B and mitomycin C, any differences among mutants and a wild type strain were not detected. These facts suggest that lesion on 6, 000 Kb chromosomal DNA was responsible for the lack of p-hydroxylation activity induced by protoplast formation and regeneration.

• Journal of Food Hygiene and Safety
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• v.13 no.4
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• pp.394-399
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• 1998

결명자의 주용성분인 노르-루브로푸사린의 함량이 높은 추출물을 얻기 위하여 결명자분말을 0~100%의 에탄올수용액으로 추출하여 고농도의 노르-루브로푸사린을 함유하는 결명자 추출물을 제조하였다. 결명자추출물과 주요 함유성분인 노르-루브로푸사린은 항산화활성과 프리라디칼소거 작용을 나타내었으며, H2O2 유도 세포독성에 대해서도 억제적으로 작용하여 cyto-protective effect를 나타내었다. 또한 DNA crosslinking agent 인 mitomycin C 유도 소핵생성에도 결명자 70% 에탄올추출물과 노르-루브로파사린이 매우 높은 억제활성을 나타내었다. 따라서 결명자 추출물과 노르-루브로푸사린은 산소라디칼들에 의한 산화적 손상 및 DNA 손상 등에 억제적으로 작용하는 기전을 활용하여 항산화성 스트레스를 통한 항노화 , 암예방제로서의 응용가능성이 높은 물질로 판단되었다.

• Microbiology and Biotechnology Letters
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• v.22 no.3
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• pp.246-251
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• 1994

Pseudomonas syringae pv. tabaci(Pa45) Tox$^{-}$ cells were infected with phage Ps90 strain isolated form the natural source, and the Ps90 lysogenized bacterial cells were then obtained. The lyxohenized cells produced tabtoxin and the phage induction occured when the cells treated with mitomycin C. The Southren hybridization alnalysis of the four EcoRI-treated plasmid fragments and the EcoRI-digested genomic DNA of Tox$^{+}$ and Tox$^{-}$ strains using phage DNA as a probe showed that only those DNA fragment of Tox$^{+}$ strain were related to the Ps90 phage DNA. Based on these results, the tabtoxin producing DNA fragments of the bacteris are presumed to have originated from the same phage DNA, and to be responsible for the pathogenecity of the bactrial strains.

• Environmental Analysis Health and Toxicology
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• v.19 no.3
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• pp.307-314
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• 2004

합성화학물질들이 환경으로의 유입은 인체에는 물론 환경생태계에 많은 영향을 미치므로 이들의 유해성 검증은 매우 중요한 일이라 할 수 있다. 실제 산업체에서 사용되는 수많은 화학물질들의 유전적 손상 유발유무는 유해성검증에서 무엇보다 중요한 일이라 할 수 있다. 이에 산업체 공정과정에서 널리 사용되는 것으로 알려진 11종의 합성화학물질에 대해 마우스의 골수 세포를 이용한 in vivo소핵시험을 수행하여, 소핵형성 유발유무를 관찰하였다. 양성대조군으로 사용된 mitomycin C는 음성대조군과 비교시 유의하게 소핵을 유발하는 반면, 비교적 마우스에서 높은 50%치사량을 보이는 thiourea, 2,4-dichlorophenol 및 2,4-toluene diisocyanate 등의 합성물질들을 비롯한 나머지 8종의 물질들은 본 실험결과 통계적으로 유의하게 소핵을 유발하지 않는 것을 관찰 할 수 있었다.

• Microbiology and Biotechnology Letters
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• v.22 no.2
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• pp.158-163
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• 1994

Microorganisms capale of utilizing linear alkylbenzene sulfonates(LAS) as sole carbon source were isolated from industrial effluent by using LAS agar plates. The isolated strains were identified as Salmonella sp(BC-2) and Escherichia sp.(BC-3) from the results of morphological, cultural and biochemical tests. The optimal condition for the growth and biodegradation of LAS was the initial pH 7.0 and LAS concentration 0.1%. The isolated BC-2 and BC-3 strains harbored plasmid and LAS-degrading activity was lost when the plasmids were cured by mitomycin C. The plasmids were transformed into E. coli and transformants have the LAS-degrading activity. Isolated strains were examined for primary biodegradation rate of LAS in the medium by methylene blueactive substance(MBAS) method. Of these isolates, BC-2 and BC-3 strains degradated LAS upto 60% and high resistant to CdCl$_{2}$ and HgCl$_{2}$. Isolated strains were sensitive to chloramphenicol, kanamycin, rifampicin, streptomycin and tetracycline but resistant to ampicillin and lincomycin.] Its minimal inhibitory concentration(MIC) for ampicillin was more than 1500 $\mu $g/ml.

• Journal of Life Science
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• v.11 no.2
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• pp.108-110
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• 2001

The E. coli expression system to overproduce a harmful protein, carboxypeptidase Taq was developed. Since expression plasmid pCK305N containing the colicin promoter already has the initiation codon on the restriction site, the initiation codon of the CPase Taq gene was removed. Expression plasmid pCP4-col includes the entire CPase Taq gene, which is directed by the colicin promoter. E. coli cells harboring pCP-col produced a high amount of the enzyme when they were cultured in the present of mitomycin C (0.4 ${\mu}g$/ml). An amount of purified enzyme produced by pCP4-col directed by the colicin promoter was 10.5 mg. This result indicated that the novel E. coli expression system controlled by the colicin promoter could produce almost twice amounts of CPase Taq than the conventional system controlled by the tart promoter.

• Korean Journal of Microbiology
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• v.29 no.1
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• pp.63-68
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• 1991

Several arsenic compound-resistant bacteria were isolated from Jung-Rang stream. The isolates, D-3, D-12, and D-14 were characterized phenotypically and genetically, and identified as Serratia liquefaciens, Klebsiella oxytoca, and Klebsiella pneumoniae, respectively. A plasmid of 67kb was found in Klebsiella oxytoca D-12 and designated as pMH12. Transfer of this plasmid from D-12 to E. coli HB101 was occurred, and the resulting transconjugant strains expressed the same level of heavy metal resistance as the donor strain. The physical presence of this plasmid in transconjugant was detected with agarose gel electrophoresis. Arsenite-sensitive derivatives of isolate D-12 were obtained with Mitomycin C treatment which cured pMH12. Antibiotics and heavy metal resistances were also examined to be used as a proper marker for the isolates in gene cloning. Isolate D-12 has resistance to several heavy metal ions such as $Cd^{2+}$ , $Zn^{2+}$ and $Hg^{ 2+}$ Also, all the other arsenite resistant isolates showed resistance to several heavy metal ions and antibiotics.

• Archives of Pharmacal Research
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• v.23 no.4
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• pp.288-301
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• 2000

A series of 2-alkyl, 2-aryl, and 2-piperazinyl benzimidazole-4,7-dione derivatives (7a-h) and 16m-o) were prepared, and their cytotoxicities were tested against three cancer cell lines (mouse lymphocytic leukemia cell line P388, and human gastric carcinoma cell lines SNU-1 and SNU-16). These compounds showed potent cytotoxicity against all of three cell lines tested, and especially SNU-16 was sensitive to them. 2-Aryl (7g,h) and 2-piperazinyl benzimidazole-4,7-dione derivative (I6 m) were more potent than mitomycin C against P388 and SNU-16. Among benzimidazole-4,7-dione derivatives with alkyl group at position 2, 7a had the most potent cytotoxicity against all of the cell lines tested.