• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.342-347
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• 2003

Clumping of cells is one of the major obstacles to culture wild myxobacterial strains in liquid media. In an effort to solve this problem, we tried a method isolating spontaneous mutants that grow dispersed in liquid media from a wild myxobacterial strain. Myxococcus stipitatus KYC1001, a newly isolated strain from Gyearyongsan National Park in Korea, clumps and sticks to the surface of culture vessels as other wild myxobacteria behave in liquid media. Taking an advantage of the characteristics that dispersed mutant cells would grow dispersed while most other wild type cells would clump and stick to the surface of culture vessels, spontaneous dispersed mutants were enriched by repeated subculturing of culture supernatant. A resultant mutant, KYC2001, did not form any clumps nor stick to the surface of culture flasks, but grew completely dispersed in liquid. Meanwhile, three other spontaneous mutants, KYC2002, KYC2003, and KYC2004, shelved partially dispersed phenotype. A major portion of the cells grew dispersed in liquid but they still formed some clumps.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.1
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• pp.25-31
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• 2009

This study was carried out to investigate the mutagenic, antimutagenic, cytotoxicity and antitumor effects of Adenophora triphylla (AT). AT was extracted with 70% ethanol and then further fractionated to hexane, chloroform, ethyl acetate, butanol and water. Antimutagenic, cytotoxicity and antitumor effects of AT extracts were measured by using Ames test, SRB method, and the tumor growth inhibition test. AT extracts did not show any mutagenicity in the Ames test; however, 70% ethanol extracts and its fractions had strong antimutagenic effects against mutation induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and 4-nitroquinoline-1-oxide (4NQO). The ethyl acetate fraction of AT (200 ${\mu}g$/plate) showed approximately 66.5% inhibitory effect on the mutagenesis induced by 4NQO against TA98 strain, whereas 83.3% and 75.1% inhibitions were observed on the mutagenesis induced by MNNG and 4NQO against TA100 strain. In anticancer effects, the cytotoxicity of AT extract and its fractions against cancer cell lines including human cervical adenocarcinoma (HeLa), human hepatocellular carcinoma (Hep3B), human breast adenocarcinoma (MCF-7), human gastric carcinoma (AGS), human lung carcinoma (A549) and transformed primary human embryo kidney (293) were investigated. The treatment of 1 mg/mL AT ethyl acetate faction had the highest cytotoxicity of 79.9%, 74.9%, 66.0%, 71.0% and 74.3% against HeLa, Hep3B, MCF-7, AGS and A549 cells, respectively. In contrast, the extract and its fractions showed only $3{\sim}36%$ cytotoxicity for a normal human kidney cell line (293). In vivo anti-cancer effect of Adenophora triphylla extract was tested using Balb/c mice transplanted sarcoma-180 cells. Adenophora triphylla ethyl acetate fraction showed the highest inhibition rate of 37.2% at the 50 mg/kg concentration.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.6
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• pp.921-929
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• 2004

Dietary intake of whole grains, vegetable and fruit is known to reduce the degenerative chronic diseases, such as cancer and cardiovascular diseases. Antioxidative and antimutagenic effects of the ethanol extract of Korean Millet, Buckwheat, Sorghum and Job's tears were examined by inhibition against iron-induced linoleate per-oxidation, DPPH (1,l-diphenyl-2-picrylhydrazyl) radical generation and MDA-BSA (malondialdehyde-bovine serum albumin) conjugation, and Ames test using Salmonella. Buckwheat showed the strongest antioxidative effect in three different systems among these four grains, but it showed the lowest antimutagenic effect. Sorghum was the second to Buckwheat in iron-induced linoleate peroxidation inhibition activity and DPPH radical scavenging activity, and showed very good direct-antimutagenic effect in 2-Nitrofluorene treated Salmonella Typhimurium TA98 and indirect-antimutagenic effect in 2-Anthramine treated Salmonella Typhimurium TA98 and TA100 with hepatic S9 mixture. Millet showed the strongest antimutagenic effect in Salmonella Typhimurium TA98 and TA 100 with or without S9. Buckwheat contained the highest total flavonoids and polyphenols, 1.14 mg/g and 3.71 mg/g, respectively. Total flavonoid content in these four grains was negatively correlated with $IC_{50}$/ for DPPH radical scavenging antioxidative effect significantly (r=-0.9924, p=0.0076), but not with antimutagenic effect.

• Environmental Analysis Health and Toxicology
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• v.18 no.2
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• pp.121-129
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• 2003

The genotoxicity of pendimethalin [N-(l-ethylpropyl)-2, 6-dinitro-3, 4-xylidine, C$\_$13/H$\_$19/N$_3$O$_4$, M.W.=281.3, CAS No. 40487-42-1], one of selective herbicide, was evaluated in bacterial gene mutation system, chromosome aberration in mammalian cell system and in vivo micronucleus assay with rodent. In bacterial gene mutation assay, pendimethalin revealed dose-dependent mutagenic potential in 313 ∼ 5,000 ${\mu}$g/plate of Salmonella typhimurium TA 98 and TA 1537 both in the absence and presence of S-9 metabolic activation system, and TA 100 only in the absence of S-9 mixture. In the TA 1535, slight increase of revertant was also observed in the presence of S-9 metabolic activation system. No mutagenic potential was observed in the TA 1535 without metabolic activation system and TA l00 in the presence of S-9 mixture. In mammalian cell system using Chinese hamster lung (CHL) fibroblast, no clastogenicity of pendimethalin was observed both in the absence and presence of S-9 metabolic activation system in the concentration range of 2.32∼9.28 ${\mu}$g/ml. And also, in vivo bone marrow micronucleus assay, pendimethalin revealed no clastogenic potential in the dose range of 203∼810 mg/kg body weight after oral administration in mice. Consequently, in vitro chromosome aberration with mammalian cells and in vivo bone marrow micronucleus assay revealed no clastogenic potential of pendimethalin. However, pendimethalin revealed mutagenic potential in bacterial gene mutation assay.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1371-1377
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• 1999

Antimutagenic and antioxidative activities in the different milling fraction of rice(Oryza sativa L., illpumbyeo) were investigated. Twelve milling fractions including embryo, bran(I, II, III, IV and all) and milled rice(I, II, III, IV and V) and were obtained by abrasive milling. Antimutagenic effects of milling fraction against Trp-P-2-induced mutagenicity were shown as ${\approx}0%$ for embryo fraction, $27{\sim}86%$ for bran fractions and $64{\sim}95%$ for milled rice fractions in salmonela typhimurium reversion assay. Milled rice V, inner fraction with 80.9% milling yields, showed the highest antimutagenic activity among milling fractions Antioxidative activity, measured by peroxide value(POV) of different milling fractions was higher in embryo(28%) and bran fractions ($25{\sim}34%)$ than milled rice fractions($6{\sim}22%)$. In terms of thiobarbituric acid(TBA). embryo. bran and milled rice fractions exhibited 14, $5{\sim}21\;and \;6{\sim}20%$ antioxidative activity, respectively. Antioxidative activity, measured by electron donating ability(EDA), was 45% for embryo fraction. $35{\sim}40%$ for bran fractions and $41{\sim}65%$ for milled rice fractions. Antimutagenic activity if milling fractions was correlated with POV (r=-0.471, p<0.01) and EDA (r = 0.609, p<0.001) but not correlated with TBA. Contents of total phenolic acid and SH were higher in bran and embryo fractions than in milled rice fractions, and were reversely correlated with antimutagenic activity (r=-0.523 and -0.451. respectively, p<0.05).

• Journal of Food Hygiene and Safety
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• v.25 no.3
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• pp.215-219
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• 2010

This study was undertaken to investigate the mutagenicity and antimutagenicity of Acanthopanax koreanum Nakai. Antimutagenic study on extract of A. koreanum was studied using the test with Salmonella typhimurium TA100, TA98. And mutagenicity study was studied using the test with S. typhimurium TA100, TA98, TA1535, TA1537 and Escherichia coli WP2 uvr A. A. koreanum was negative in Ames test with S. typhimurium and E. coli with or without S-9 mixture. Test substances of $5000\;{\mu}g/{\mu}l$, $2500\;{\mu}g/{\mu}l$ and $600\;{\mu}g/{\mu}l$ of A. koreanum extracts were chosen via toxicity test. Ames test was performed on positive control group, experimental group and negative control group in the presence of the metabolic activation system and metabolic non-activation system. As a result, there was no coherent increase and reverse mutation in all concentrations. Therefore, A. koreanum does not cause reverse mutation. In addition, A. koreanum showed strong antimutagenic activities in S. typhimurim TA100 and TA98. In conclusion, A. koreanum root may be an excellent antimutagenic agent.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.796-801
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• 2010

This study was carried out to establish a system for mutation breeding by irradiation of gamma-ray in $Rosa$ $hybrida$ Hort. The rooted cuttings of two roses, 'Spidella' and 'Cabernet' were irradiated with different gamma-ray doses (0, 30, 50, 70, 90, 110, 130, 150 and 170 Gy) from a $^{60}Co$ source to reveal an optimal dose for induction of mutants. The irradiated plants were planted in a greenhouse, and investigated on the appearance of petal color mutants and shoot growth by gamma ray dose. The 50% lethal doses ($LD_{50}$) of plant were 110 Gy for 'Spidella' and 150 Gy for 'Cabernet', respectively. The 50% decrease dose of shoot length was observed at 70-90 Gy dose for 'Spidella', and 110 Gy dose for 'Cabernet'. Solid, chimeric and mosaic petal mutants with various colors were induced from pink petal of 'Spidella' and red petal of 'Cabernet' when 30-170 Gy dose was irradiated. The mutants obtained from 'Spidella' had white, ivory, pinky ivory, light pink and deep pink petal colors. The mutants obtained from 'Cabernet' had pink, deep pink, purple red (magenta), orange red and purple petal colors. It was suitable to irradiate 70-90 Gy dose for 'Spidella' and 90-110 Gy dose for 'Cabernet' for the induction of various mutants considering plant survival rate, shoot growth and mutant occurrence rate.

• Journal of Life Science
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• v.13 no.2
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• pp.184-190
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• 2003

Myxococcus xanthus is a Gram negative, rod-shaped, soil bacterium that displays a social behaviors, and multicellular development upon nutrient deprivation. The csgA gene encoding a cell surface protein is essential for developmental behaviors including rippling, aggregation, fruiting body formation and sporulation. csgA mutants show normal vegetative growth, but lack all these developmental phenotypes. Expression of the CsgA (C-signal) specific genes are eliminated or dramatically reduced in csgA mutants. In order to identify components of C-signal transduction pathway, second site mutations were introduced into csgA mutants and were identified which can fully or partially restore development of csgA mutants (Rhie, H. G. et. al. 1989. J. Bacteriol. 171, 3268-3276). One of such csgA suppressor mutations, socD500 restores only sporulation to csgA mutants at 15$^{\circ}C$. The socD500 mutaion however eliminates the three basic developmental requirements, starvation, high cell density and a solid surface. Only sporulation, not accompanied with fruiting body formation is induced simply by shifting the temperature of vegetatively growing cells from $32^{\circ}C$ to $15^{\circ}C$. Spores induced by socD500 mutation is not as thick as that of wild-type fruiting body. In socD500 genetic background, two of ten C-signal dependent genes, $\Omega$DK4506 and $\Omega$DK4406 are more highly expressed in growing cells at $15^{\circ}C$. These results indicate that the socD500 mutation may be partly involved in the regulation of expression of two C-signal dependent genes and genes for sporulation in this transduction pathway.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.900-905
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• 2001

In this study, the levels of insoluble dietary fiber(IDF) and soluble dietary fiber (SDF) in Perilla frutescens seed were quantified and antimutageinc effects of perilla seeds extracts (method extract, hexane extract, methanol soluble fraction and dietary fiber)was carried out IDF and SDF values of perilla seeds were 16.1% and 1.1% , respectively, with 17.2 of total fiber content. Among the solvent extracts of perilla seeds, methanol extract and methanol soluble fraction (MSF) effectively inhibited the mutagenicity induced by aflatoxin B$_{1}$(AFB$_{1}$)in Salmonella typhimurium TA100, Methanol extract of perilla seeds showed 91% inhibition against AFB$_{1}$ mutagen under the 2.5 mg/assay concentration, and MSF inhibited the mutagenicity of 87% by adding 1.25,g/assay. However, perilla seed extracts showed low inhibition rate on the mutagenicity induced by N-methyl-N-nitro-N-nitosoguanidine(MNNG). And also, SDF and hexane extracts from perilla seeds did not show the antimutagenic effects against AFB$_{1}$ and MNNG. On the hand, IDF extracted from perilla seeds inhibited 21% of mutagenicity induced Trp-P-2 due to the carcinogen binding effect.

• Korean journal of applied entomology
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• v.13 no.4 s.21
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• pp.245-249
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• 1974

In order to establish a dose limits for subsequent induced mutation research itl Pyricularia oryzae, X-ray sensitivity of the conidia and the vegetative hypae of the fungus, race N-1, was investigated. Conidia of the fungus irradiated with X-rays reduced significantly in spore germination inversely with radiation doses. A severe suppression of conidia germination in about $80\%$ was found at the dose of 120kR, and the rests of the conidia produce very short and lysed germ tubes. A stimulated effect was observed in the elongation of hyphae from the conidia of 10 kR irradiation at initial stage of the growth. The radiosensitivity of hyphae was exremely higher than that of conidia with the increase of radiation doses. It was also recognized that the frequency of X-ray induced mutation in pathogenicity was directly proportional to radiation doses.