• Food Science and Preservation
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• v.11 no.3
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• pp.405-410
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• 2004

Leuconostoc mesenteroides subsp. cremoris DLAB19 were investigated under various culture conditions to maximize the production of antimutagenic substance(s) against aflatoxin Bl(AFBl) on Salmonella enterica serovar Typhimurium TAI00 and TA98. The MRS medium containing glucose(2$\%$) as a carbon source and yeast extract(1 $\%$) as a nitrogen source resulted in the highest production of the antimutagenic substance(s) against aflatoxin Bl(AFBl) in the culture supernatant of Leu. mesenteroides subsp. cremoris DLAB19. Optimal pH of the medium, culture temperature and shaking speed for the antimutagenic substance(s) production were pH 7.0, 30$^{\circ}C$ and 150 rpm, respectively. Under the optimal condition, the antimutagenic effects of Leu. mesenteroides subsp. cremoris DLAB19 culture supernatant were 87.11 $\%$ on S. enterica serovar Typhimurium TA100 and 75.04 S. enterica serovar Typhimurium TA98.

• Journal of KIISE:Software and Applications
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• v.28 no.11
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• pp.833-841
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• 2001

Abstract In this work, we analyze the Levy mutation operations based on the Levy probability distribution in the evolutionary programming via the mean square displacement and the distinctness. The Levy probability distribution is characterized by an infinite second moment and has been widely studied in conjunction with the fractals. The Levy mutation operators not only generate small varied offspring, but are more likely to generate large varied offspring than the conventional mutation operators. Based on this fact, we prove mathematically, via the mean square displacement and the distinctness, that the Levy mutation operations can explore and exploit a search space more effectively. As a result, one can get better performance with the Levy mutation than the conventional Gaussian mutation for the multi-valued functional optimization problems.

• Korean Journal of Microbiology
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• v.37 no.4
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• pp.305-311
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• 2001

Antifungal bacterium, Bacillus subtilis YS1 was isolated from Yusong hot spring showed broad antifungal spectrum against 12 kinds of plant pathogenic fungi and Candida albicans, animal pathogen. From the gamma($Co^{60}$) radiation sensitivity test, $D_10$ value was 2.08 kGy and it survived above 20 kGy of radiation dose. Several mutants were induced by gamma radiation. Among them, YS1-1009 mutant showed resistance against tebuconazole of herbicide, increased activity against Botryoshaeria dothidea and ligninase activity. YS67 mutant was antifungal deficient auxotrophic mutants(trp-pro-or arg-ura-). From this results, it suggested that gamma irradiation could be useful method for mutant induction.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.2
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• pp.27-34
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• 1979

Dormant rice seeds were treated with different levels of ethyl methanesulfonate(EMS) and sown directely on the well managed seed beds and the ontogenetically different tillers of $_{x}\textrm{M}_1 plants were marked as they are developed. The biological effects of $_{x}\textrm{M}_1 plant and mutation frequency of $_{x}\textrm{M}_2 were investigated. utation frequency evaluated with tiller groups and $_{x}\textrm{M}_1 sterility, differs from the results reported with radiation treatment. Hence, selection of $_{x}\textrm{M}_1 panicle of primary or secondary tillers could be recommended for increase mutation frequency in $_{x}\textrm{M}_2 generation.

• Journal of Food Hygiene and Safety
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• v.7 no.4
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• pp.161-168
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• 1992

On the mutagenicity induced by 3-amino-l,4-dimethyl-5-H-pyrido[4,3-b]indol (Trp-P-1) and 2-aminotluorene (2-AF), the antimutagenic effects of edible muntain herb juices were examined by the Ames assay using Salmonella typhimurium TA98 and TA100. Juices prepared from aralia bud, small water dropwort, mugwort, roots of belltlower and sedum didn't have mutagenicity. Most of sample juices showed the antimutagenicity. Especially, juices prepared from aralia bud, small water dropwort and mugwort were found to possess strong antimutagenic effects. Sedum was moderatly effective and root of belltlower had little effect on mutagenicity caused by Trp-P1 and 2-AF. The experimental results with TA98 were similar to those with TA100 in the antimutagenicity test of edible mountain herb juices. In this study, antimutagenicity on Trp-P-1 was more effective than that on 2-AF.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1281-1287
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• 1997

This study was conducted to investigate the antimutagenic effects of methyl alcohol extracts from Auricularia auricula and Gyrophora esculenta on the SOS response induced by 4-nitroquinoline-1-oxide (4NQO), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), mitomycin C (MMC) and 3-amino-1,4- dimethyl-5H-pyrido-[4,3-b]indol (Trp-P-1) in E. coli PQ37/plasmid pKM101. In the mutagenic test on test strain, both methyl alcohol extracts did not show mutagenic activity. In the antimutagenic test, each sample strongly inhibited the mutagenecity induced by 4NQO, MNNG, MMC and Trp-P-1. Methyl alcohol extracts from Auricularia auricula and Gyrophora esculenta showed inhibitory effects of 52% and 59% against 4NQO, 49% and 58% against MNNG, 53% and 64% against MMC, and 61% and 64% against Trp-P-1, respectively. Gyrophora esculenta extracts on the antimutagenicity showed relatively higher inhibitory effects than that of Auricularia auricula.

• Journal of the Korea Society of Computer and Information
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• v.10 no.6 s.38
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• pp.85-92
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• 2005

In this Paper, we develope an effective web-based learning contents using interactive genetic algorithms with modified mutation operation. In the interactive genetic algorithm, reciprocal exchange mutation is used. But. we modify the mutation operator to improve the learning effects. The new web-based learning contents using interactive genetic algorithm provide the dynamic learning contents providing and real-time test system. Especially, learners can execute the interactive genetic algorithm according to the learners' characters and interests to select the efficient learning environments and contents sequences.

• Environmental Mutagens and Carcinogens
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• v.10 no.2
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• pp.107-112
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• 1990

돼지 췌장 유래 엘라스타제의 돌연변이원성을 알아보기 위하여 포유동물 세포를 이용한 돌연변이 시험과 마우스를 이용한 소핵시험을 실시하였다. 엘라스타아제에 의하여 CHO-K1-BH4 cell이 6-thioguanine에 대해 내성을 가지게 되는 변이의 빈도를 조사하였다. 시험결과 엘라스타아제의 농도 증가 (0-30mg/ml)에 따른 변이빈도의 증가가 관찰되지 않았으며, 변이빈도도 음성대조군 변이빈도 치의 2배 이상을 보이지 않았다. 마우스를 이용한 소핵시험에서는 엘라스타아제를 1250, 2500 그리고 5000mg/kg의 용량으로 마우스에 1회 경구 투여 하였으며 양성대조군과 음성대조군에는 각각 mitomycin C 2mg/kg, 10skim milk 20ml/kg 을 각각 복강내와 경구로 투여하였다. 시험결과 엘라스타제 투여군의 소핵 출현빈도는 음성대조군과 비교하여 증가하지 않았다. 위의 결과로 보아 엘라스탄제는 이 시험계들에서 돌연변이원성이 없는 것으로 사려된다.

• The Korean Journal of Mycology
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• v.21 no.3
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• pp.230-234
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• 1993

In order to isolate mutants in Rhizopus nigricans, the optimal treatment conditions for the chemical mutagens, N-Methyl-N'-Nitro-N-Nitrosoguanidine(MNNG) and Ethyl Methane Sulphonate(EMS), were explored. When MNNG was used as the chemical mutagen, the optimum concentration and treatment time for the best mutation frequency were $125{\mu}g/ml$ and 60 minutes, respectively. Under the optimum conditions for MNNG, the survival rate was 0.1-1.0%. The leucine auxotroph could be isolated. The phenotypic characteristics of the three mutants prepared are as follows; shortened sporangiophore, spiral sporangiophore, and reduced size of sporangium and sporangiospore. However, EMS as the chemical mutagen was ineffective for this species.

• The Korean Journal of Food And Nutrition
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• v.11 no.1
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• pp.72-76
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• 1998

Gardenia yellow pigment produced by Gardenia jasminoides Ellis was tested for reverse mutagenic test in Salmonella typhimurium stains TA1535, TA1537, TA98 and TA100 at concentrations raging form 6.25 to 200$\mu\textrm{g}$/$m\ell$ per plate. No significant reverse mutagenic activity was observed in any of the S. typhimurium strains, in either presence or absence of S9 mix. There was no toxicity to the bacteria. These result indicate that yellow pigment doesn't have mutagenicity.