• KSBB Journal
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• 제14권2호
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• pp.188-191
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• 1999

본 실험에서는 하이브리도마세포 배양 중 아미노산 량의 변화를 조사하여 세포성장, 세포대사 및 항체생산성에 미치는 아미노산의 영향을 조사하였다. 실험결과에 의하면 vR8 하이브리도 마세포 배양 중 세포성장이 급속히 이루어지는 시점과 최대 세포농도에 도달한 시점에서의 glutamine, arginine, leucine 등 다수 아미노산의 고갈이 관찰되었고, 이후 세포활성이 급속히 저하되었다. 이때 glucose 농도, lactate, armmonia 등의 대사산물 농도 및 pH, DO, 교반속도 등은 적절하게 유지되었기 때문에 이들 요소에 의한 세포성장의 저해는 없었다. 따라서 이들 아미노산의 고갈이 세포활성의 저하에 커다란 영향을 주었다고 생각된다. 한편, 고갈된 아미노산을 첨가한 배지(GC-HY-S2)로 배양을 해본 결과 세포농도를 $2.91\times10^7$cell/mL까지 증가시킬 수 있었다. 즉, 변형배지에서는 세포활성의 저하를 가져오는 세포성장구간을 지나 계속적인 세포성장을 보여 27배 정도 더 높은 최대 세포농도를 보였다. 세포농도의 증가로 specific productivity, volumetric productivity도 각각 1.75배, 56배 증가하였다. 최대 세포농도에서의 아미노산 량을 조사한 결과를 보면 충분한 양의 아미노산이 공급되었음을 알 수 있다. 고농도 하이브리도마세포 배양에서의 일부 아미노산의 고갈은 일반적으로 관찰되는 현상이다. 그러므로 세포를 고농도로 배양하기 위해서는 아미노산 분석을 통해 고갈된 아미노산을 첨가해 주어야 하는데, 아미노산의 요구는 세포주마다 다르므로 배지 최적화과정에서 아미노산 분석에 의한 배지의 개선이 필요하다고 생각된다.

• 환경생물
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• 제31권2호
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• pp.158-164
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• 2013

환경시료에서 마이크로시스틴 분해능을 나타낸 균주 1종을 분리하였고 16S rRNA gene sequence 분석 결과, Microbacterium sp.로 동정되어 Microbacterium sp. MA21로 명명하였다. R2A배지를 기본 배지로 하여 $50{\mu}g\;L^{-1}$ microcystin-LR을 첨가하여 $30^{\circ}C$, 12시간 동안 배양한 후 PPIA를 통해 microcystin이 80% 이상 분해되는 것을 확인하였다. Microcystin-LR의 분해를 HPLC 분석을 통해 재확인하였고, microcystin 분해산물로 추정되는 두 개의 peak를 확인하였다. 16S rRNA 염기서열을 이용한 계통분류 분석 결과, 본 연구에서 분리한 Microbacterium sp. MA21은 Alphaproteobacteria의 Sphingomonas 속에 속하지 않는 것은 물론 Actinobacteria에는 속하지만 기존에 보고되지 않은, 새로운 genus로 확인되었다.

• 한국식품위생안전성학회지
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• 제5권3호
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• pp.131-138
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• 1990

Aflatoxins is a chemically diverse group of toxic secondary metabolites that are produced by fungi and often occur in agricultural commodities. Because of their wide range of toxic effects, Aflatoxins cause severe economic losses to farmers and livestock producers and pose a health to human consuming contaminated foods. Long term prospects for biotechnological control of Aflatoxins require elucidation of the specific steps and regulation of their biosynthetic pathways . Aflatoxin determinations can be approached many ways. It is essential to safely handle all experimental materials associated with aflatoxin analysis or aflatoxigenic fungi Visual screening of suspect samples, base on the presence of conidial head of the aspergillus flavus group, and screening samples for the presence of bright greenish yellow flourescence are not chemical tests and such screening techniques may allow aflactoxin contaminated lots into commerce. Microcolumn screening procedures should always be used in conjunction with a quantitative method. Several thin layer chromatography(TLC) and high performance liquid chromatography(HPLC) methods are suitable for quantitation and are in general use. Immunochemical Methods such as the ELISA or affinity column chromatography methods are being rapidly developed. The chemical and immunochemical methods can be reliable if care is taken, using suitable controls and personnel that are well trained . All analytical laboratories should stress safety and include suitable analytical validation procedure. Especially a worldwide enquiry was undertaken in recent to obtain up-to-date information about aflatoxin legislation in as many countries of the world as possible. The information concerns aflatoxin in foodstuffs. aflatoxin MI in dairy products, aflatoxins in animal feedstuffs. Limits and regulations for aflatoxin have been expended in recent with more countries having legislation on subject, more products, and more aflatoxins covered by this legislation.

• 한국식품영양학회지
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• 제28권1호
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• pp.84-93
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• 2015

Relationship between lipid intake and obesity has been well-addressed but recent findings indicated that the type of lipid or composition of lipid in the diet also contributes to body fat accumulation and consequential health outcome. The purpose of this study was to investigate the status of nutrition intake including fatty acids, lipids and lipid soluble nutrients between the obese and lean college students and to analyze the relationship between the intake of certain fatty acids and body fat accumulation. Anthropometric elements including body weight, height, body fat and composition were measured, and dietary recall was conducted on a total of 114 college students. Data showed that total calorie intake and total lipid intake were not significantly different between the obese and lean subjects, in both male and female students. However, male obese subjects ate more amount of plant lipids and palmitic acids (C16:0) from their diet (p<0.05), while female obese subjects consumed more linoleic acids (18:2) and linolenic acids (C18:3) compared to normal subjects (p<0.01). Correlation analysis revealed that the consumption of palmitoleic acid (C16:1) and lipid soluble vitamin D were negatively (p<0.05) correlated with body fat accumulation in all subjects and these findings were supported by simple linear regression analyses for those variables. These results implicate that rather than only considering the amount of lipids, suggesting a proper type of lipids or lipid metabolites can be considered in nutrition counseling or education.

• 동의생리병리학회지
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• 제18권6호
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• pp.1805-1809
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• 2004

In order to validate the use of Radix Curcumae Aromaticae as an anti-inflammatory drug in the traditional Korean medicine, I have investigated the effect of water-soluble extract of Radix Curcumae Aromaticae (ECA) on the expression of inducible heme oxygenase-1 (HO-1), which ha.s anti-inflammatory and cytoprotective effects stimulates, in human umbilical vein endothelial cells (HUVECs) stimulated with a high dose of pro-inflammatory tumor necrosis factor-alpha (TNF-α). The extract protected dose-dependently HUVECs against TNF-α-induced apoptosis, as measured qualitatively by a nuclear staining method using the fluoresoence DAPI and quantitatively by a flow cytometry using fluoresce-enhanced Annexin V antibody, and significantly Increased HO-1 expression, as determined by Western blotting analysis using anti-HO-1 antibody. Biockage of HO-1 activity by a pharmacological inhibitor reversed cytoprotection afforded by the extract, and treatment with carbon monoxide, one of HO-1 metabolites, resulted in cytoprotection comparable to the extract. These results suggest that ECA may have therapeutic potential in the control of endothelial disorders caused by inflammatory cytokines.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권6호
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• pp.85-94
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• 2015

RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) is the most important explosive contaminant, both in concentration and in frequency, at military shooting ranges in which green technologies such as phytoremediation or constructed wetlands are the best option for mitigation of explosive compounds discharge to the environment. A study was conducted with two identical lab-scale plug flow constructed wetlands planted with Amur silver grass to treat water artificially contaminated with 40 mg/L of toxic explosive compound, RDX. The reactor was inoculated with or without RDX degrading mixed culture to evaluate plant-microorganism interactions in RDX removal, transformation products distribution, and kinetic constants. RDX and its metabolites in water, plant, and sediment were analyzed by HPLC to determine mass balance and kinetic constants. After 30 days of operation, the reactor reached steady-state at which more than 99% of RDX was removed with or without the mixed culture inoculation. The major transformation product was TNX (Trinitroso-RDX) that comprised approximately 50% in the mass balance of both reactors. It was also the major compound in the plant root and shoot system. Acute toxicity analysis of the water samples showed more than 30% of toxicity reduction in the effluent than that of influent containing 40 mg/L of RDX. In the Amur silver grass mesocosm seeded with the mixed culture, the specific RDX removal rate, that is 1st order removal rate normalized to plant fresh weight, was estimated to be 0.84 kg⁻¹ day⁻¹ which is 16.7% higher than that in the planted only mesocosm. Therefore, the results of this study proved that Amur silver grass is an effective plant for RDX removal in constructed wetlands and the efficiency can be increased even more when applied with RDX degrading microbial consortia.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2003년도 제2차 연례학술대회 발표논문집
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• pp.251-257
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• 2003

Metabolic engineering has become a new paradigm for the more efficient production of desired bioproducts. Metabolic engineering can be defined as directed modification of cellular metabolism and properties through the introduction, deletion, and modification of metabolic pathways by using recombinant DNA and other molecular biological tools. During the last decade, metabolic flux analysis(MFA) has become an essential tool fur metabolic engineering. By MFA, the intracellular metabolic fluxes can be quantified by the measurement of extracellular metabolite concentrations in combination with the stoichiometry of intracellular reactions and mass balances. The usefulness and functionality of MFA are demonstrated by applying to metabolic pathways in E. coli. First, a large-scale in silico E. coli model is constructed, and then the effects of carbon sources on intracellular flux distributions and succinic acid production were investigated on the basis of the uptake and secretion rates of the relevant metabolites. The results indicated that succinic acid yields increased in order of gluconate, glucose and sorbitol. Acetic acid and lactic acid were produced as major products rather than when gluconate and glucose were used carbon sources. The results indicated that among three carbon sources available, the most reduced substrate is sorbitol which yields efficient succinic acid production.

• ALGAE
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• 제27권4호
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• pp.303-313
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• 2012

Cyanobacteria are well known for their production of a multitude of highly toxic and / or allelopathic compounds. Among the photosynthetic microorganisms, cyanobacteria, belonging to the genus Nostoc are regarded as good candidate for producing biologically active secondary metabolites which are highly toxic to humans and other animals. Since so many reports have been published on the poisoning of different animals from drinking water contaminated with cyanobacteria toxins, it might be assumed that bioactive compounds are found only in aquatic species causes toxicity. However, the discovery of several dead dogs, mice, ducks, and fish around paddy fields, prompted us to study the toxic compounds in a strain of Nostoc which is most abundant in the paddy fields of Iran, using polymerase chain reaction and liquid chromatography coupled with a diode array detector and mass spectrophotometer. Results of molecular analysis demonstrated that the ASN_M strain contains the nosF gene. Also, the result of ion chromatograms and $MS^2$ fragmentation patterns showed that while there were three different peptidic compound classes (anabaenopeptin, cryptophycin, and nostocyclopeptides), there were no signs of the presence of anatoxin-a, homoanatoxin-a, hassallidin or microcystins. Moreover, a remarkable antifungal activity was identified in the methanolic extracts. Based on the results, this study suggests that three diverse groups of potentially bioactive compounds might account for the death of these animals. This case is the first documented incident of toxicity from aquatic cyanobacteria related intoxication in dogs, mice, and aquatic organisms in Iran.

• 한국미생물·생명공학회지
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• 제25권6호
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• pp.592-597
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• 1997

During the screening of inhibitors against phospholipase C (PLC) and the formation of inositol phosphates (IP$_{t}$) at NIH3T3${\gamma}$1 cells from microbial secondary metabolites, we selected a fungal strain MT60109 which was capable of producing an inhibitor. By the taxonomic studies, this fungus was identified as Pseudallescheria sp. MT60109 and an inhibitor of PLC was purified by BuOH extraction and chromatographic techniques from the culture broth of Pseudallescheria sp. MT60109. The inhibitor was identified as thielavin B by the physico-chemical properties and spectroscopic analysis of UV, FAB-MS, $^{1}$H, $^{13}$C-NMR, $^{1}$H-$^{1}$H COSY and HMBC. Thielavin B showed potent inhibitory activity against PLC purified from bovine brain with an IC$_{50}$ of 20 $\mu$M. And it also inhibited the formation of inositol phosphates in platelet-derived growth factor (PDGF) -stimulated NIH3T3${\gamma}$1 cells with an IC$_{50}$ of 20 $\mu$M.

• Journal of Microbiology and Biotechnology
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• 제19권10호
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• pp.1244-1249
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• 2009

Endophytic fungi are known for the production of valuable metabolites, but information on the gibberellin production capacity of this group is limited. We isolated 9 endophytic fungi from the roots of salt-stressed soybean plants and screened them on waito-c rice, in order to identify plant growth promoting fungal strains. The fungal isolate TK-2-4 gave maximum plant length (20.35 cm) promotion in comparison with wild-type Gibberella fujikuroi (19.5 cm). In a separate experiment, bioassay of TK-2-4 promoted plant length and biomass of soybean cultivar Taegwangkong. The TK-2-4 culture filtrate was analyzed for the presence of gibberellins, and it was found that all physiologically active gibberellins, especially $GA_4$ and $GA_7$, were present in higher amounts ($GA_1$, 0.11 ng/ml; $GA_3$, 2.91 ng/ml; $GA_4$, 3.21 ng/ml; and $GA_7$, 1.4 ng/ml) in conjunction with physiologically inactive $GA_9$ (0.05 ng/ml), $GA_{12}$ (0.23 ng/ ml), $GA_{15}$ (0.42 ng/ml), $GA_{19}$ (0.53 ng/ml), and $GA_{20}$ (0.06 ng/ml). The fungal isolate TK-2-4 was later identified as a new strain of Phoma herbarum, through the phylogenetic analysis of 28S rDNA sequence.