• Title/Summary/Keyword: Citrate reduction

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Distinct functional roles of peroxiredoxin isozymes and glutathione peroxidase from fission yeast, Schizosaccharomyces pombe

  • Kim, Ji-Sun;Bang, Mi-Ae;Lee, Song-Mi;Chae, Ho-Zoon;Kim, Kang-Hwa
    • BMB Reports
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    • v.43 no.3
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    • pp.170-175
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    • 2010
  • Chaperone;Glutathione peroxidase;Peroxiredoxin;Schizosaccharomyces pombe;Thioredoxin peroxidase;To investigate the differences in the functional roles of peroxiredoxins (Prxs) and glutathione peroxidase (GPx) of Schizosaccharomyces pombe, we examined the peroxidase and molecular chaperone properties of the recombinant proteins. TPx (thioredoxin peroxidase) exhibited a capacity for peroxide reduction with the thioredoxin system. GPx also showed thioreoxin-dependent peroxidase activity rather than GPx activity. The peroxidase activity of BCP (bacterioferritin comigratory protein) was similar to that of TPx. However, peroxidase activity was not observed for PMP20 (peroxisomal membrane protein 20). TPx, PMP20, and GPx inhibited thermal aggregation of citrate synthase at 43$^{\circ}C$, but BCP failed to inhibit the aggregation. The chaperone activities of PMP20 and GPx were weaker than that of TPx. The peroxidase and chaperone properties of TPx, BCP, and GPx of the fission yeast are similar to those of Saccharomyces cerevisiae. The fission yeast PMP20 without thioredoxin-dependent peroxidase activity may act as a molecular chaperone.

Effect of Feeding with Different Source of Carbohydrate and HCA on Body Weight Gain and Lipid Metabolism in Rats (탄수화물 급원에 따른 HCA의 공급이 흰쥐의 체중 및 지질 대사에 미치는 영향)

  • Son, Young-Ae;Jeong, Hye-Jin;Shim, Jee-Ae;Kwon, Sang-Hee;Kim, Mi-Kyung
    • Journal of Nutrition and Health
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    • v.40 no.8
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    • pp.675-683
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    • 2007
  • This study was conducted to investigate the effects of feeding different carbohydrate sources and garcinia cambogia extract(HCA) on body weight and lipid metabolism. Fifty 10-month-old male Sprague-Dawley rats weighting $635{\pm}6g$ were randomly divided into 5 groups and fed different experimental diets for 4 weeks. The carbohydrate(CHO) sources of each group were cornstarch(control group, 100% of CHO), fructose(F group and FH group, 25% of CHO) and sucrose(S group and SH group, 25% of CHO). FH group and SH group were fed diets containing 1%(W/W) of HCA. Food intake, body weight gain, and calorie efficiency were not significantly different among the groups. Perirenal fat pad weight of FH group was significantly lower than F group, but epididymal fat pad weight was not different among the groups. Fasting glucose level were not significant among the groups. Plasma lipid profile of FH or SH group was slightly lower than F or S group, respectively. The degree of difference of plasma lipid level was greater between F and FH group than those of between S and SH group. In liver, total lipid, triglyceride and total cholesterol level were slightly higher in F group than S group, and tended to be lower in FH group than F group, but tended to be higher in SH group than S group. Liver citrate lyase activity were not significant among the groups. These results suggest that HCA is potential material for reduction of body weight and improvement of plasma lipid profiles. But, there was no difference between fructose intake with HCA and sucrose intake with HCA in reduction of body weight and lipid metabolism.

Studies on the Decomposition of Environmental Pollutants by Utilizing Microorganisms (미생물을 이용한 환경오염원의 분해에 관한 연구 II)

  • 이재구;김기철;김창한
    • Korean Journal of Microbiology
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    • v.20 no.2
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    • pp.53-66
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    • 1982
  • 1. When Chong Ju and Chung Ju soils possessing different physicochemical properties were treated with 500 ppm of TOK and incubated in flooded anaerobic condition for 2, 4, and 6 months, respectively, they produced 4-Chloro-4'-amino diphenyl ether, 2,4-Dichloro-4'-amino diphenyl ether(amin-TOK), N-[4'-(4-Chlorophenoxy)] phenyl acetamide, and N-[4'-(4-Chlorophenoxy)] phenyl formamide as the metabolities. This result indicates that TOK undergose the reduction of its $NO_2\;to\;NH_2$ group, dechlorination, acetylation, and formylation under this condition. The cleavage of ether linkage does not occur. In addition, TOK degrades more readily in Chung Ju soil which is characterized by pH 6.43 and higher contents of $Ca^{++}$ and C.E.C. than in Chong Ju soil which is lower in pH, $Ca^{++}$, and C.E.C. 2. In the aerobic incubation of TOK of 25ppm in Chung Ju soil suspension for 21 days, the ratio of the resulting metabolites, TOK : amino-TOK : 4-Chloro-4'-amino diphenyl ether was 100 : 130 : 76. Meanwhile, in the 42 day incubation, the ratio was 100 : 19 : 5, which indicates that TOK in aerobic condition dose not necessrily degrade as a function of the incubation period. 3. The citrate buffer extract of Chung Ju soil has the capability of degrading TOK, which was verified to be due to the action of the microorganisms involved. 4. Twelye strains of soil bacteria were isolated from the TOK-treated soils. In the incubation of TOK in pure cultures of the respective isolates, the strain T-1-1 isolated from Chong Ju soil had almost no degradability whereas the strain T-2-3 was the most potent. The degradation of TOK by the isolates constituted mostly the reduction of the nitro group to amino group. 5. In a test for the degradability of TOK by some selected microorganisms, Pseudomonas species were more potent than fungi. Yet, Isolate B which had been isolated from Chung Ju soil suspension was the most potent.

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Feasibility Study of Activation of Persulfate by Fe(II) for Phenol Contaminated Sediment (Fe(II)에 의해 활성화된 과황산을 이용한 페놀 오염 퇴적물 처리 타당성 평가)

  • Jo, Jae Hyun;Yoon, Seong-Eun;Kim, Jae-Moon;Hwang, Inseong
    • Journal of Soil and Groundwater Environment
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    • v.25 no.4
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    • pp.77-86
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    • 2020
  • Persulfate-based advanced oxidation processes (AOPs) can oxidize various organic pollutants. In this study, persulfate/Fe(II) system was utilized in phenol removal, and the effect of various organic and inorganic chelators on Fe(II)-medicated persulfate activation was investigated. The feasibility of persulfate/Fe(II)/chelator in cleanup of phenol-contaminated sediment was confirmed through toxicity assessment. In persulfate/Fe(II) conditions, the rate and extent of phenol removal increased in proportion to persulfate concentration. In chelator injection condition, the rate of phenol removal was inversely proportional to chelator concentration when it was injected above optimum ratio. Thiosulfate showed greater chelation tendency with persulfate than citrate and interfered with persulfate access to Fe(II), making the latter a more suitable chelator for enhancing persulfate activation. In contaminated clay sediment condition, 100% phenol removal was obtained within an hour without chelator, with the removal rate increased up to four times as compared to the rate with chelator addition. A clay sediment toxicity assessment at persulfate:Fe(II):phenol 20:10:1 ratio indicated 71.3% toxicity reduction with 100% phenol removal efficiency. Therefore, persulfate/Fe(II) system demonstrated its potential utility in toxicity reduction and cleanup of organic contaminants in sediments.

Limiting Pink Discoloration in Cooked Ground Turkey in the Absence or Presence of Sodium Tripolyphosphate Produced from Presalted and Stored Raw Ground Breasts

  • James R. Claus;Jong Youn Jeong
    • Food Science of Animal Resources
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    • v.43 no.2
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    • pp.331-345
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    • 2023
  • The effects of pink inhibiting ingredients (PII) to eliminate the pink color defect in cooked turkey breast produced from presalted and stored raw ground turkey in the absence or presence of sodium tripolyphosphate (STP) were examined. Ground turkey breast was mixed with 2% sodium chloride and vacuum packaged. After storage for 6 d, ten PII were individually incorporated without or with added STP (0.5%) as follows: none (control), citric acid (CA; 0.1%, 0.2%, 0.3%), calcium chloride (CC; 0.025%, 0.05%), ethylenediaminetetraacetic acid disodium salt (EDTA; 0.005%, 0.01%), and sodium citrate (SC; 0.5%, 1.0%). Treatments were cooked at a fast or slow cooking rate, cooled, and stored before analysis. All PII tested were capable of lowering inherent pink color compared to the control (No STP: CIE a* pooled day reduction of 23.0%, 5.2%, 12.6%, and 12.6% for CA, CC, EDTA, and SC, respectively; STP: reduction of 21.5%, 17.4%, 6.0%, and 18.2% for CA, CC, EDTA, and SC, respectively). For samples without STP, fast cooking rate resulted in higher CIE a*. However, slow cooking resulted in more red products than fast cooking when samples included STP. Presalting and storage of ground turkey caused the pink discoloration in uncured, cooked turkey (CIE a* 6.24 and 5.12 for without and with STP). This pink discoloration can be decreased by inclusion of CA, CC, EDTA, or SC, but incorporation of CA decreased cooking yield. In particular, the addition of SC may provide some control without negatively impacting the cooking yield.

Characterization of Microbial Diversity of Metal-Reducing Bacteria Enriched from Groundwater and Reduction/Biomineralization of Iron and Manganese (KURT 지하심부 지하수 내 토착 금속환원미생물의 종 다양성 및 철/망간의 환원과 생광물화작용)

  • Kim, Yumi;Oh, Jong-Min;Jung, Hea-Yeon;Lee, Seung Yeop;Roh, Yul
    • Economic and Environmental Geology
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    • v.47 no.4
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    • pp.431-439
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    • 2014
  • The purposes of this research were to investigate the enrichment of metal-reducing bacteria from KURT groundwater and the identification of the microbial diversity by 16S rRNA as well as to examine microbial Fe(III)/Mn(IV) reduction and to analyze morphological features of interactions between microbes and precipitates and their mineralogical composition. To cultivate metal-reducing bacteria from groundwater sampled at the KURT in S. Korea, different electron donors such as glucose, acetate, lactate, formate, pyruvate and Fe(III)-citrate as an electron accepter were added into growth media. The enriched culture was identified by 16S rRNA gene sequence analysis for the diversity of microbial species. The effect of electron donors (i.e., glucose, acetate, lactate, formate, pyruvate) and electron acceptors (i.e., akaganeite, manganese oxide) on microbial iron/manganese reduction and biomineralization were examined using the 1st enriched culture, respectively. SEM, EDX, and XRD analyses were used to determine morphological features, chemical composition of microbes and mineralogical characteristics of the iron and manganese minerals. Based on 16S rRNA gene analysis, the four species, Fusibacter, Desulfuromonas, Actinobacteria, Pseudomonas sp., from KURT groundwater were identified as anaerobic metal reducers and these microbes precipitated metals outside of cells in common. XRD and EDX analyses showed that Fe(III)-containing mineral, akaganeite (${\beta}$-FeOOH), reduced into Fe(II)/Fe(III)-containing magnetite ($Fe_3O_4$) and Mn(IV)-containing manganese oxide (${\lambda}-MnO_2$) into Mn(II)-containing rhodochrosite ($MnCO_3$) by the microbes. These results implicate that microbial metabolism and respiratory activities under anaerobic condition result in reduction and biomineralization of iron and manganese minerals. Therefore, the microbes cultivated from groundwater in KURT might play a major role to reduce various metals from highly toxic, mobile to less toxic, immobile.

Electrochemical Reduction of Carbon Dioxide Using Porous La0.8Sr0.2CuO3 Electrode (다공성 La0.8Sr0.2CuO3 전극을 이용한 이산화탄소의 전기화학적 환원 반응)

  • Kim, Jung Ryoel;Lee, Hong Joo;Park, Jung Hoon
    • Korean Chemical Engineering Research
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    • v.52 no.2
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    • pp.247-255
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    • 2014
  • $La_{0.8}Sr_{0.2}CuO_3$ powder with the perovskite structure was prepared as electrode catalyst using citrate method. Porous electrode was made with as-prepared catalyst, carbon as supporter and polytetrafluoroethylene (PTFE) as hydrophobic binder. As results of potentiostatic electrolysis with potential of -1.5~-2.5 V vs. Ag/AgCl in 0.1, 0.5 and 1.0 M KOH at 5 and $10^{\circ}C$ on the porous electrode, liquid products were methanol, ethanol, 2-propanol and 1, 2-butanol regardless reaction temperature, while gas products were methane, ethane and ethylene at $5^{\circ}C$, and methane, ethane and propane at $10^{\circ}C$ respectively. Optimal potentials for $CO_2$ reduction in the view of over all faradic efficiency were high values (-2.0 and -2.2 V) for gas products whereas low potential (-1.5 V) for liquid products regardless of concentration and temperature.

Exercise training and selenium or a combined treatment ameliorates aberrant expression of glucose and lactate metabolic proteins in skeletal muscle in a rodent model of diabetes

  • Kim, Seung-Suk;Koo, Jung-Hoon;Kwon, In-Su;Oh, Yoo-Sung;Lee, Sun-Jang;Kim, Eung-Joon;Kim, Won-Kyu;Lee, Jin;Cho, Joon-Yong
    • Nutrition Research and Practice
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    • v.5 no.3
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    • pp.205-213
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    • 2011
  • Exercise training (ET) and selenium (SEL) were evaluated either individually or in combination (COMBI) for their effects on expression of glucose (AMPK, PGC- $1{\alpha}$, GLUT-4) and lactate metabolic proteins (LDH, MCT-1, MCT-4, COX-IV) in heart and skeletal muscles in a rodent model (Goto-Kakisaki, GK) of diabetes. Forty GK rats either remained sedentary (SED), performed ET, received SEL, ($5\;{\mu}mol{\cdot}kg$ body $wt^{-1}{\cdot}day^{-1}$) or underwent both ET and SEL treatment for 6 wk. ET alone, SEL alone, or COMBI resulted in a significant lowering of lactate, glucose, and insulin levels as well as a reduction in HOMA-IR and AUC for glucose relative to SED. Additionally, ET alone, SEL alone, or COMBI increased glycogen content and citrate synthase (CS) activities in liver and muscles. However, their effects on glycogen content and CS activity were tissue-specific. In particular, ET alone, SEL alone, or COMBI induced upregulation of glucose (AMPK, PGC-la, GLUT-4) and lactate (LDH, MCT-1, MCT-4, COX-IV) metabolic proteins relative to SED. However, their effects on glucose and lactate metabolic proteins also appeared to be tissue-specific. It seemed that glucose and lactate metabolic protein expression was not further enhanced with COMBI compared to that of ET alone or SEL alone. These data suggest that ET alone or SEL alone or COMBI represent a practical strategy for ameliorating aberrant expression of glucose and lactate metabolic proteins in diabetic GK rats.

Enhanced Internalization of Macromolecular Drugs into Mycobacterium smegmatis with the Assistance of Silver Nanoparticles

  • Sun, Fangfang;Oh, Sangjin;Kim, Jeonghyo;Kato, Tatsuya;Kim, Hwa-Jung;Lee, Jaebeom;Park, Enoch Y.
    • Journal of Microbiology and Biotechnology
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    • v.27 no.8
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    • pp.1483-1490
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    • 2017
  • In this study, silver nanoparticles (AgNPs) were synthesized by the citrate reduction process and, with the assistance of n-hydroxysuccinimide and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, were successfully loaded with the macromolecular drug vancomycin (VAM) to form AgNP-VAM bioconjugates. The synthesized AgNPs, VAM, and AgNP-VAM conjugate were characterized by UV-visible spectroscopy, zeta potential analysis, confocal microscopy, and transmission electron microscopy. The effect of loading VAM onto AgNPs was investigated by testing the internalization of the bioconjugate into Mycobacterium smegmatis. After treatment with the AgNP-VAM conjugate, the bacterial cells showed a significant decrease in UV absorption, indicating that loading of the VAM on AgNPs had vastly improved the drug's internalization compared with that of AgNPs. All the experimental assessments showed that, compared with free AgNPs and VAM, enhanced internalization had been successfully achieved with the AgNP-VAM conjugate, thus leading to significantly better delivery of the macromolecular drug into the M. smegmatis cell. The current research provides a new potential drug delivery system for the treatment of mycobacterial infections.

Electrochemical Behavior of Nanostructured Fe-Pd Alloy During Electrodeposition on Different Substrates

  • Rezaei, Milad;Haghshenas, Davoud F.;Ghorbani, Mohammad;Dolati, Abolghasem
    • Journal of Electrochemical Science and Technology
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    • v.9 no.3
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    • pp.202-211
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    • 2018
  • In this work, Fe-Pd alloy films have been electrodeposited on different substrates using an electrolyte containing $[Pd(NH_3)_4]^{2+}$ (0.02 M) and $[Fe-Citrate]^{2+}$ (0.2 M). The influences of substrate and overpotential on chemical composition, nucleation and growth kinetics as well as the electrodeposited films morphology have been investigated using energy dispersive X-ray spectroscopy (EDS), current-time transients, scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD) patterns. In all substrates - brass, copper and sputtered fluorine doped tin oxide on glass (FTO/glass) - Fe content of the electrodeposited alloys increases by increasing the overpotential. Also the cathodic current efficiency is low due to high rate of $H_2$ co-reduction. Regarding the chronoamperometry current-time transients, it has been demonstrated that the nucleation mechanism is instantaneous with a typical three dimensional (3D) diffusion-controlled growth in the case of brass and copper substrates; while for FTO, the growth mode changes to 3D progressive. At a constant overpotential, the calculated number of active nucleation sites for metallic substrates is much higher than that of FTO/glass; however by increasing the overpotential, the number of active nucleation sites increases. The SEM micrographs as well as the XRD patterns reveal the formation of Fe-Pd alloy thin films with nanostructure arrangement and ultra-fine grains.