• Nutrition Research and Practice
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• v.5 no.5
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• pp.412-420
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• 2011

The aim of the present study was to investigate the hypocholesterolemic effect and potential of tyramine derivatives from Lycii Cortex Radicis (LCR), the root bark of lycium (Lycium chenese Miller) in reducing lipid peroxidation. The activities of enzymes, hepatic 3-hydroxy 3-methylglutaryl (HMG) CoA reductase and acyl-CoA:cholesterol acyltransferase (ACAT) and LDL oxidation were measured in vitro and animal experiments were also performed by feeding LCR extracts to rats. The test compounds employed for in vitro study were trans-N-p-coumaroyltyramine (CT) and trans-N-feruloyltyramine (FT), LCR components, N-(p-coumaroyl)serotonin (CS) and N-feruloylserotonin (FS) from safflower seeds, ferulic acid (FA) and 10-gingerol. It was observed that FT and FS at the concentration of 1.2 mg/mL inhibited liver microsomal HMG CoA reductase activity by ~40%, but no inhibition of activity was seen in the cases of CT, CS, FA and 10-gingerol. Whereas, ACAT activity was inhibited ~50% by FT and CT, 34-43% by FS and CS and ~80% by 10-gingerol at the concentration of 1 mg/mL. A significant delay in LDL oxidation was induced by CT, FT, and 10-gingerol. For the animal experiment, five groups of Sprague-Dawley male rats were fed high fat diets containing no test material (HF-control), 1 and 2% of LCR ethanol extract (LCR1 and LCR2), and 1% of extracts from safflower seed (Sat) and ginger (Gin). The results indicated that total cholesterol level was significantly lower in Saf, LCR2 and Gin groups, and HDL cholesterol level was lower only in Gin group when compared with HF-control group; while there was no difference in the serum triglyceride levels among the five experimental groups. The level of liver cholesterol was significantly lower in LCR1 and LCR2 groups than HF-control Serum levels of TBARS were significantly lower only in LCR2 group when compared with HF-control group. From the observed results, we concluded that LCR can be utilized as a hypocholesterolemic ingredient in combination with ginger, especially for functional foods.

• Nutrition Research and Practice
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• v.4 no.1
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• pp.3-10
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• 2010

This study was performed to investigate the effect of desalinated underground seawater (named as 'magma seawater', MSW) of Jeju Island in Korea on lipid metabolism and antioxidant activity. MSW was collected from underground of Han-Dong in Jeju Island, and freely given to high fat diet (HFD)-fed C57BL/6 mice for 10 weeks. Although there were no significant differences in the body weight changes and plasma lipid levels, hepatic triglyceride levels were significantly lower in the MSW group than in the normal tap water (TW)-drunken control group. Furthermore, the activity of fatty acid synthase (FAS) was significantly decreased and carnitine palmitoyltransferase (CPT) activity was increased in MSW group compared to TW group. Similarly, real-time PCR analysis revealed that mRNA expressions of lipogenic genes were lowered in MSW groups compared to the control group. In a morphometric observation on the liver tissue, accumulation of fats was remarkably reduced in MSW group. Meanwhile, in vitro assay, tree radical scavenging activity measured by using diphenylpicrylhydrazyl (DPPH) was increased in MSW group. The 2'-7'-dichlorofluorescein diacetate (DCF-DA) staining followed with fluorescent microscopy showed a low intensity of fluorescence in MSW-treated HepG2 cells, compared to TW-treated HepG2 cells, which indicated that the production of reactive oxygen species by tert-butyl hydroperoxide (t-BHP) in HepG2 cells was decreased by MSW treatment. The antioxidant effect of MSW on t-BHP-induced oxidative stress in HepG2 cells was supported by the increased activities of intracellular antioxidant enzymes such as catalase and glutathione reductase. From these results, we speculate that MSW has an inhibitory effect on lipogenesis in liver and might play a protective role against cell damage by t-BHP-induced oxidative stress.

• Journal of the Korean Applied Science and Technology
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• v.32 no.3
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• pp.568-577
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• 2015

To protect skin problems, new natural material alternative to synthetic antioxidants has been extensively selected from natural sources such as plants, animals, and microorganisms. Poncirus trifoliata of those has been widely used as treatment of allergy, chronic inflammatory diseases, and natural antioxidant. In recent days, microbial fermentation to natural products has been reported to increase feasibly their bioavailability. Accordingly, we performed the fermentation using hot water extract of Poncirus trifoliata by isolated Leuconostocs sp. strain JYK and investigated the change of antioxidative activity. Antioxidative material such as hesperidine naringine, imperatorin, and luteolin was found in hot water extract of Poncirus trifoliata. Total phenolics compounds and flavoniods in hot water extract were $71.2{\pm}4.58GAE(mg/g)$ and $25.1{\pm}4.12$ hesperidine(mg/g), respectively. After fermentation, their values were $89.2{\pm}13.47GAE(mg/g)$ and $31.0{\pm}4.06$ hesperidine(mg/g), respectively. After fermentation, ABTS[2,2-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid)] and DPPH(1,1-diphenyl-2-picrylhydrazyl) radical were highly enhanced from $70.2{\pm}9.01$ to $86.2{\pm}3.72$ and $18.7{\pm}1.81$ to $26.6{\pm}4.06$, respectively. Thus microbial fermentation offers a tool to further increase the bioactive potential of Poncirus trifoliata.

• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.312-319
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• 2002

The Sporosarcina psychrophilia pyrB gene, which encodes aspartate transcarbamylase (ATcase), was cloned on Sau3AI restriction endonuclease fragment inserted into pUC19 plasmid vector, S. psychrophilia pyrB gene was expressed in Escherichia coli pyrB mutant for the complementation test. The sequence of 2,606 nucleotides including putative pyrB gene was determined. The region contained one full open reading frame (ORf) and two partial ORFs. The deduced amino acid sequence of the second ORF showed 59% identity with that of Bacillus caldolyticus ATCase. The first and third partial ORFs were closely related to the uracil permease (pyrP) and dihydroorotase (pyrC), respectively. Besides, potential terminator, antiterminator, and anti-antiterminator structures were found in the intergenic region between pyrP and pyrB. These results suggested that S. psychrophilia pyrimidine nucleotide biosynthesis genes are clustered as well as other Bacillus sp. Over-expressed product of pyrB encoding ATCase was purified and analyzed by the SDS-PAGE. The purified PyrB protein turned out to be molecular mass of 27 kDa and showed ATCase activity.

• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.114-120
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• 2002

A 1,989-bp genomic region encoding nickel resistance genes was isolated from Legionella pneumophila, a pathogen for legionellosis. From a sequencing and computer analysis, the region was found to harbor two structural genes, a nreB-like protein gene (1,149 bp) and a nreA-like protein gene (270 bp), in a row. Both genes exhibited a significant degree of similarity to the corresponding genes from Synechocystis sp. PCC6803 ($54\%$ amino acid sequence identity) and Achromobacter xylosoxidans 31A ($76\%$). The gene was successfully expressed in E. coli MG1655 and conferred a nickel resistance of up to 5 mM in an LB medium and 3 mM in a TMS medium including gluconate as the sole carbon source. E. coli harboring the nickel resistance gene also exhibited a substantial resistance to cobalt, yet no resistance to cadmium or zinc. Since the extracellular concentration of nickel remained constant during the whole period of cultivation, it was confirmed that the nickel resistance was provided by an efflux system like the $Ni^2＋$permease (nrsD) of Synechocystis sp. strain PCC6803. Since polyphosphate (poly-P) is known as a global regulator for gene expression as well as a potential virulence factor in E. coli, the nickel resistance of a ppk mutant of E. coli MG 1655 harboring the nickel resistance gene from L. pneumophila was compared with that of its parental strain. The nickel resistance was significantly attenuated by ppk inactivation, which was more pronounced in an LB medium than in a TMS medium.

• Journal of Microbiology and Biotechnology
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• v.30 no.10
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• pp.1467-1479
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• 2020

Profiling the transcriptome changes involved in xylose metabolism by the fungus Trichoderma reesei allows for the identification of potential targets for ethanol production processing. In the present study, the transcriptome of T. reesei HJ-48 grown on xylose versus glucose was analyzed using next-generation sequencing technology. During xylose fermentation, numerous genes related to central metabolic pathways, including xylose reductase (XR) and xylitol dehydrogenase (XDH), were expressed at higher levels in T. reesei HJ-48. Notably, growth on xylose did not fully repress the genes encoding enzymes of the tricarboxylic acid and respiratory pathways. In addition, increased expression of several sugar transporters was observed during xylose fermentation. This study provides a valuable dataset for further investigation of xylose fermentation and provides a deeper insight into the various genes involved in this process.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.2
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• pp.73-80
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• 2015

An investigation on the removals of tetracycline (TTC), which is a family of antibiotics widely founded in the environment, from the aqueous solution by birnessite(${\delta}-MnO_2$)-mediated oxidative transformation was described. This study also examined the potential effect of the naturally occurring substances, humic acid (HA) on the oxidative transformation. The experiment was carried out in various conditions (reaction time, Mn oxide loadings, pH) and in the presence of HA as a batch test. The removals of TTC followed pseudo-first order reactions, and rate constants (k, $hr^{-1}$) for the removals of TTC were constantly increased with decreasing pH from 0.98 (pH 9) to 2.97 (pH 3). The rate constants also increased about 1.3 times when the birnessite loading increased from 1 to 2 g/L. Presence of HA (5 mg-C/L, at $pH{\geq}6$) caused some enhancement in the removals of TTC as compared to the control, and also showed the removal efficiencies of TTC in the birnessite mediated systems (TTC=0.25 mM, ${\delta}-MnO_2=2.0g/L$, pH 6) increased with increasing HA concentrations (1~10 mg-C/L). The results obtained from the oxidative transformation of TTC and the effect of HA were discussed in terms of reaction characteristics and mechanism.

• Journal of the Korean Magnetic Resonance Society
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• v.11 no.2
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• pp.85-94
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• 2007

Vanilloid receptor I [transient receptor potential vanilloid subfamily member 1 (TRPV1), also known as VR1] is a non-selective cationic channel activated by noxious heat, vanilloids, and acid, thereby causing pain. VR1 possesses six transmembrane domain and N-and C-terminus cytosolic domains, and appears to be a homotetramer. We studied the structural properties of Cterminus of VR1 (VR1C) using CD and NMR spectroscopy. DPC micelles, with a zwitterionic surface, and SDS micelles, with a negatively charged surface, were used as a membrane mimetic model system. Both SDS and DPC micelles could increase the stability of helical structures and/or reduce the aggregation form of the VR1C. However, the structural changing mode of the VR1C induced by the SDS and DPC micelles was different. The changes according to the various pHs were also different in two micelles conditions. Because the net charges of the SDS and DPC micelles are negative and neutral, respectively, we anticipate that this difference might affect the structure of the VR1C by electrostatic interaction between the surface of the VR1C and phospholipids of the detergent micelles. Based on these similarity and dissimilarity of changing aspects of the VR1C, it is supposed that the VR1C probably has the real pI value near the pH 7. Generally, mild extracellular acidic pH ($6.5{\sim}6.8$) potentiates VRI channel activation by noxious heat and vanilloids, whereas acidic conditions directly activate the channel. The channel activation of the VRI might be related to the structural change of VR1C caused by pH (electrostatic interactions), especially near the pH 7. By measuring the $^1-^{15}N$ TROSY spectra of the VR1C, we could get more resolved and dispersed spectra at the low pH and/or detergent micelles conditions. We will try to do further NMR experiments in low pH with micelles conditions in order to get more information about the structure of VR1C.

• Korean Chemical Engineering Research
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• v.48 no.3
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• pp.327-331
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• 2010

Porcine placenta was treated with alkali, acid and enzyme treatment to obtain extracts. Heavy metal contents such as Pb, As, and Hg were low enough to satisfy cosmetic agent standard. As a result of safety test(MTT assay), porcine placenta extracts showed over 80% of cell viability at $50{\mu}g/ml$, and cell toxicity was relatively lower. From antioxidation test using DPPH free radical scavenging assay, antioxidation effect was highest as 63% at $50{\mu}g/ml$ when porcine placenta was treated with alkali in pH 9. From whitening effect test using tyrosinase inhibition assay, tyrosinase inhibition effect was 30% at $50{\mu}g/ml$ concentration in alkali treated procine placenta, however, the efficiency was lower compared with arbutin or vitamin C. In anti-wrinkle effect test from elastase inhibition assay, elastase inhibition effects were 20~30% at $50{\mu}g/ml$ for 5 kinds of porcine placenta treatments, which was superior to standard, and especially, protease treated extracts showed best results. Skin formulation including 1% porcine placenta was made and the formulation was very stable for temperature and storage period. From this research, porcine placenta extract showed high potential for anti-wrinkle functional cosmetic agent.

• Korean Journal of Microbiology
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• v.52 no.4
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• pp.437-443
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• 2016

In this study Streptomyces strains were isolated from soils and their antifungal activities and involved mechanisms were investigated. Among over 400 isolates of actinomycetes, Streptomyces costaricanus HR391 was selected as a potential antagonist to control several plant-pathogenic fungi. S. costaricanus HR391 inhibited mycelial growth of Fusarium oxysporum f. sp. raphani, F. oxysporum f. sp. niveum, F. oxysporum f. sp. lycopersici, and Rhizoctonia solani by 26.5, 26.2, 21.2, and 23.8%, respectively compared to those of uninoculated control after 7-day incubation on PDB medium. S. costaricanus HR391 produced $89{\mu}M$ of siderphore, and showed fungal cell wall-degrading activity including $0.46{\mu}mol/min/mg$ of chitinase and $0.83{\mu}mol/min/mg$ of ${\beta}$-1,3 glucanase. S. costaricanus HR391 secreted 87.49 mg/L of rhamnolipid, and produced 9.49 mg/L and 4.3 mM of lipopeptide, iturin A and surfactin, respectively, all they are membrane-disrupting biosurfactants. It also produced antimicrobial peptide and antibiotics phenazine. In addition to antifungal substances, S. costaricanus HR391 secreted plant growth-promoting phytohormones, zeatin, gibberellins and IAA. These results suggest that S. costaricanus HR391 may be utilized as an environment-friendly biocontrol agent against some important pathogenic fungi.