• 방사선산업학회지
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• 제8권1호
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• pp.1-5
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• 2014

This study investigated the reduction of microbial population and sensory properties in red pepper powders irradiated by gamma ray, electron beam, and X-ray. Populations of total aerobic bacteria and yeast & molds in red pepper powders were decreased by irradiation treatment in a dose-dependent manner. Gamma ray, electron beam, and X-ray at doses above 8 kGy caused 100% inhibition on growth of aerobic bacteria in red pepper powders. Inhibitory activity of X-ray on sterilization of red pepper powders was significantly equal to or higher compared to gamma ray and electron beam. Color and off flavor in red pepper powders were no significant difference among the control and samples irradiated with gamma ray, electron beam, and X-ray. As a result, the gamma ray, electron beam, and X-ray irradiation can be used to sterilize the microbial growth in red pepper powders without quality loss.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권5호
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• pp.451-461
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• 2005

The effect of carbon dioxide on yeast growth was investigated during the cultivation of pH 5.0 and pH 6.8. by replacing the nitrogen part with carbon dioxide under aerobic conditions. The values of the specific growth rate under pH 5.0 and pH 6.8 conditions became 64.0% and 46.9%, respectively, compared to those before the change in gas composition. This suggests that the effect of carton dioxide was greater pronounced in pH 6.8 than in pH 5.0. The genome-wide transcriptional response to elevated carbon dioxide was examined using a DNA microarray. As for upregulated genes, it was noteworthy that 3 genes were induced upon entry into a stationary phase and 6 genes were involved in stress response. Of 53 downregulated genes, 22 genes were involved in the ribosomal biogenesis and assembly and 5 genes were involved in the lipid metabolism. These facts suggest that carbon dioxide could bring the cell conditions partially to a stationary phase. The ALD6 gene encoding for cytosolic acetaldehyde dehydrogenase was downregulated, which would lead to a lack of cell components for the growth. The downregulation of ALD6 was greater in pH 6.8 than in pH 5.0. consistent with physiological response. This suggests that it might be the most effective factor for growth inhibition.

• Applied Biological Chemistry
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• 제38권4호
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• pp.283-288
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• 1995

시판 농약류의 미생물에 대한 독성을 검정한 결과 제초제인 paraquat(1,1'-dimethyl-4,4'-bipyridylium dichloride)가 편성혐기성 세균을 제외한 세균류와 효모 및 곰팡이에 걸치는 광범위한 미생물의 증식을 저해하였다. Paraquat는 $1.0\;{\mu}M$(0.186ppm)의 농도에서도 공시균(Escherichia coli KCTC 1039)의 turbidometric growth를 지연시켰으나, 생균수 변화 및 well test 등의 결과로부터 공시균에 대한 paraquat의 생육저지 최소 농도는 1.0mM(186ppm)로 평가되었다. Paraquat 처리시 공시균의 생균수는 처리직후에 대조구의 약 50%로 급격히 감소되었으나, 이후 4시간 동안 1.0mM의 paraquat 존재하에서도 유의적으로 증가되었다. 그러나 처리 4시간 이후로는 생균수가 서서히 감소되었으며 계속된 배양에도 불구하고 재증식은 관찰되지 아니하였다.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2001년도 춘계학술발표대회
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• pp.52-52
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• 2001

Many nucleoside diphosphate (NDP) kinases are ubiquitous enzymes responsible for the exchange of ${\gamma}$-phosphates between tri- and diphosphonucleosides. The catalytic Many nucleoside diphosphate (NDP) kinases are ubiquitous enzymes responsible for the exchange of ${\gamma}$-phosphates between tri- and diphosphonucleosides. The catalytic reaction follows a ping-pong mechanism in which the enzyme is transiently phosphorylated on a histidine residue conserved in all nucleoside diphosphate kinases. Beside their role in nucleotide synthesis, these enzymes present additional functions, possibly independent of catalysis, in processes such as differentiation, cell growth, tumor progression, metastasis and development. To clone murine nm23-M5, several expressed sequence tags (ESTs) of the GenBank data base, selected according to their homology to nm23-H5 cDNA, reconstituted a complete open reading frame (GenBank AF222750). To test whether murine NDPKs (1, 2, 3, 4, 5, and 6) can inhibit Bax-mediated toxicity in yeast, co-transformation was performed respectively. The yeast S.cerevisiae was transformed with a copy expression plasmid containing the histidine selection marker and expressing murine Bax under the control of a galactose-inducible promoter. Several clones were selected and found to be growth inhibited when Bax expression was induced with galactose. A representative clone was transformed again with a copy expression plasmid containing the tryptophane selection marker and expressing either murine Bcl-xL or NDPK under the control of a galactose-inducible promoter. Several subclones of the double-transformants were selected and characterized. The ability of Bcl-xL and NDPKs to suppress Bax-mediated toxicity was determined by growing yeast cells overnight in galactose media and spot-testing on galactose plates starting with an equal number of yeast cells as determined by taking the OD$_{600}$. Ten-fold serial dilutions were used in the spot-test. Plates were grown at 3$0^{\circ}C$ for 2-3 days. All murine NDPKs suppressed Bax dependent apoptosis. Futher study will be peformed whether Bax-toxicity inhibition was caused by NDP kinase activity or additional function.n.

• Molecules and Cells
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• 제28권6호
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• pp.575-581
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• 2009

Ornithine decarboxylase (ODC) is a rate-limiting enzyme in the biosynthesis of polyamines, which are essential for cell growth, differentiation, and proliferation. This report presents the characterization of an ODC-encoding cDNA (SlitODC) isolated from a moth species, the tobacco cutworm, Spodoptera litura (Lepidoptera); its expression in a polyamine-deficient strain of yeast, S. cerevisiae; and the recovery in polyamine levels and proliferation rate with the introduction of the insect enzyme. SlitODC encodes 448 amino acid residues, 4 amino acids longer than B. mori ODC that has 71% identity, and has a longer C-terminus, consistent with B. mori ODC, than the reported dipteran enzymes. The null mutant yeast strain in the ODC gene, SPE1, showed remarkably depleted polyamine levels; in putrescine, spermidine, and spermine, the levels were > 7, > 1, and > 4%, respectively, of the levels in the wild-type strain. This consequently caused a significant arrest in cell proliferation of > 4% of the wild-type strain in polyamine-free media. The transformed strain, with the substituted SlitODC for the deleted endogenous ODC, grew and proliferated rapidly at even a higher rate than the wild-type strain. Furthermore, its polyamine content was significantly higher than even that in the wild-type strain as well as the spe1-null mutant, particularly with a very continuously enhanced putrescine level, reflecting no inhibition mechanism operating in the putrescine synthesis step by any corresponding insect ODC antizymes to SlitODC in this yeast system.

• Genomics & Informatics
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• 제7권4호
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• pp.203-207
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• 2009

The target of rapamycin (TOR) signaling pathway conserved from yeast to human plays critical roles in regulation of eukaryotic cell growth. It has been shown that TOR pathway is involved in several cellular processes, including ribosome biogenesis, nutrient response, autophagy and aging. However, due to the functional diversity of TOR pathway, we do not know yet some key effectors of the pathway. To find unknown effectors of TOR signaling pathway, we took advantage of a green fluorescent protein (GFP)-tagged collection of budding yeast Saccharomyces cerevisiae. We analyzed protein abundance changes by measuring the GFP fluorescence intensity of 4156 GFP-tagged yeast strains under inhibition of TOR pathway. Our proteomic analysis argues that 83 proteins are decreased whereas 32 proteins are increased by treatment of rapamycin, a specific inhibitor of TOR complex 1 (TORC1). We found that, among the 115 proteins that show significant changes in protein abundance under rapamycin treatment, 37 proteins also show expression changes in the mRNA levels by more than 2-fold under the same condition. We suggest that the 115 proteins indentified in this study may be directly or indirectly involved in TOR signaling and can serve as candidates for further investigation of the effectors of TOR pathway.

• 한국축산식품학회지
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• 제22권1호
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• pp.66-71
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• 2002

예천산 프로폴리스는 ethanol과 butanol 분획물이 S.typhimurium과 B. subtilis에 강한 항미생물 활성을 보였으며, 용매별로는 butanol, ethyl acetate, chloroform 분획물의 순이었다. C. utilis와 A. niger에는 모든 분획물이 항균활성을 나타내지 않았다. 농도별 균생육 억제 시험 결과, E. coli의 경우 예천산은 0.4mg/ml에서 초기에 균증식이 억제되었으며 영월은 0.25mg/ml에서 12시간 이후 균증식이 완전히 억제되었다. S. aureus의 경우, 영월과 예천산 프로폴리스가 0.25와 0.30mg/ml에서 완전히 균증식을 억제시켰다. P. aeruginosa의 경우, 예천산 프로폴리스는 0.20mg/ml에서 12시간 이후 균생장 억제를 보였으며, 영월산 프로폴리스는 0.20mg/ml에서 균생장이 완전히 억제되었다. S. typhimurium의 경우, 영월산은 0.20, 0.25mg/ml에서 균증식이 거의 억제되었으며, 예천산은 0.40mg/ml에서 균증식이 거의 억제되었다. MIC는 예천산 프로폴리스가 P. aeruginosa가 >0.2mg/ml로 가장 낮았고 S. aureus 0.25mg/ml, S. typhimurium > 0.35mg/ml 순이었다. 영월산은 P. aeruginosa가 0.15mg/ml로 가장 낮았으며 E. coli, S. aureus 및 S. typhimurium이 0.25mg/ml, B. subtilis 와 C. utilis는 각각 0.3, 0.4mg/ml 이었다.

• 생명과학회지
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• 제18권2호
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• pp.228-233
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• 2008

본 연구는 60여 종의 자생 향장식물 및 한약재의 에탄올 추출물의 항균활성을 분석하였다. 양성 대조군인 페녹시에탄올을 처리한 군에서의 저해존의 크기에 대한 실험군의 상대적 비율을 분석한 결과 P. aeruginosa 에 대해서는 단삼과 황련에서 가장 강한 항균력이 나타났다. 이는 양성 대조군에서 보인 저해존의 단삼의 경우 97%, 황련의 경우 84% 에 해당하였으며 그 외에도 작약, 스테비아, 때죽나무, 후리지아, 생강나무, 뽕나무, 오배자, 지유, 황금에서 항균력이 나타났다. S. aureus에 대해서는 오배자, 황련, 단삼이 가장 강한 항균력을 나타냈다. 이는 양성 대조군에서 보인 저해존의 오배자의 경우 78%, 황련의 경우 99%, 단삼의 경우 92%에 해당하였다. 또한 작약, 찔레, 스테비아, 창포, 후리지아, 오디, 생강나무, 구절초, 고삼, 관중, 지유, 황금, 은행나무, 소나무, 인동초, 이나무에서 항균력을 나타냈다. C. albicans에 대해서는 황금의 경우 35%, 황련의 경우 33%의 항균 활성을 보였다. M. furfur에 대해서는 오배자에서 가장 강한 항균력이 나타났는데 양성 대조군에서 보인 저해존의 57%에 해당하였으며 그 외에도 작약, 찔레, 황련, 진피, 목단피에서 항균력이 나타났다. P. acnes 에 대해서는 황련, 단삼, 오배자, 작약에서 가장 강한 항균력이 나타났다. 이는 양성 대조군에서 보인 저해존의 황련과 단삼의 경우 99%, 오배자의 경우 87%에 해당하였으며, 작약의 경우 꽃에서 추출한 경우 89%, 줄기에서 추출한 경우 35%, 뿌리에서 추출한 경우 22%에 해당하였다. 또한 찔레, 스테비아, 창포, 오디, 오이, 은방울꽃, 생강나무, 구절초, 고삼, 관중, 지유, 후박에서도 항균력이 나타났다. 이상의 결과에서 지리산 자생식물 중에서는 작약, 찔레, 생강나무, 구절초, 소나무에서, 한약재 중에서는 황련, 오배자, 지유, 단삼, 황금에서 강한 항균력을 보였고, 관련되는 성분과 가능한 작용 방식을 논의하였다.

• 한국환경농학회지
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• 제23권1호
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• pp.68-74
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• 2004

억새즙액을 이용하여 유용한 미생물의 대량배양을 위한 새로운 배지를 개발하고자 본 연구를 수행하였다. 억새즙액의 성분을 조사한 결과 칼륨 (37,952 mg/L), 질소 (14,000 mg/L), 인산 (6,800mg/L), 마그네슘 (5,969 mg/L), 칼슘 (5,910 mg/L) 등이 주성분을 차지하였다. 본 연구를 위하여 먼저 식물병원성균인 뿌리썩음병 원인균인 Rhizoctonia solani, 잿빛곰팡이 병을 일으키는 Botrytis cinerea에 대하여 강력한 저해 활성을 갖는 길항균 G-74를 토양으로부터 분리하였으며, 이 균의 형태관찰과 MIDI 분석을 통하여 Bacillus lentimorbus G-74 균주로 최종 동정하였다. 이 균의 억새즙액 배지에 대한 최적 배양조건을 조사한 결과 30% (V/V) 희석배지, $35^{\circ}C$ 배양온도, 5.0의 초기 배지 pH에서 가장 좋은 성장을 기록하였다. 또한 이 배지에 탄소원으로서 2.0% (W/V)의 corn starch 및 질소 원으로서 1.0% (W/V)의 yeast extract를 추가적으로 첨가하면 최상의 성장을 보여주었으며, 이 경우 대조구인 LB 배지보다도 균체성장이 66% 이상 증가하였다.

• Preventive Nutrition and Food Science
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• 제10권2호
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• pp.122-129
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• 2005

Chlorine dioxide $(ClO_2)$ treatment was evaluated for microbial growth inhibition and its effects on the quality of vacuum-packaged chicken breasts. Chicken breast samples were treated with 3, 50, and 100 ppm of $ClO_2$ solution, respectively. After $ClO_2$ treatment, chicken breast samples were individually vacuum-packaged and stored at $4^{\circ}C$, a typical storage temperature for meat and meat product, for 7 days. The vacuum-packaged chicken breasts treated with $ClO_2$ had significantly lower total bacteria, yeast and mold, total coliform, and Salmonella spp. were significantly reduced by $ClO_2$ treatment. $D_{10}-values$ of total bacteria count, yeast and mold, total coliform, and Salmonella spp. in vacuum-packaged chicken breasts was 93, 83, 85, and 50 ppm, respectively. The pH of vacuum-packaged chicken breasts decreased with increasing $ClO_2$ concentration. Thiobarbituric acid reacted substance (TBARS) values of vacuum-packaged chicken breasts increased during storage, regardless of $ClO_2$ concentration. $ClO_2$ treatment caused negligible changes in Hunter L, a, and b values in the vacuum-packaged chicken breasts. Sensory evaluation of the vacuum-packaged chicken breasts showed that there were no significant changes among the samples treated with various $ClO_2$ concentration. These results indicate that $ClO_2$ treatment could be useful in improving the microbial safety and quality of meat products.