• Korean Journal of Environmental Agriculture
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• v.38 no.4
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• pp.245-253
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• 2019

BACKGROUND: Weathering of bottom ash (BA) might induce change of its surface texture and pH and affect physical and chemical properties of soil associated with greenhouse gas emission, when it is applied to the arable soil. This study was conducted to determine effect of weathering of BA in mitigating emission of greenhouse gases from upland soil. METHODS AND RESULTS: In a field experiment, methane (CH₄), carbon dioxide (CO₂), and nitrous oxide (N₂O) emitted from the soil was periodically monitored using closed chamber. Three month-weathered BA and non-weathered BA were applied to an upland soil at the rates of 0, 200 Mg ha^-1. Maize (Zea mays L.) was grown from July 1_st to Oct 8_th in 2018. Both BAs did not affect cumulative CH₄ emission. Cumulative CO₂ emission were 23.1, 19.8, and 18.8 Mg/ha/100days and cumulative N₂O emission were 35.8, 20.9, and 17.7 kg/ha/100days for the control, non-weathered BA, and weathered BA, respectively. Weathering of BA did not decrease emission of greenhouse gases significantly, compared to the weathered BA in this study. In addition, both BAs did not decrease biomass yields of maize. CONCLUSION: BA might be a good soil amendment to mitigate emissions of CO₂ and N₂O from arable soil without adverse effect on crop productivity.

• Journal of Plant Biotechnology
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• v.44 no.2
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• pp.191-202
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• 2017

Chemical compounds from four different tissues of the kenaf plant (Hibiscus cannabinus), a valuable medicinal crop originating from Africa, were examined to determine its potential for use as a new drug material. Leaves, bark, flowers, and seeds were harvested to identify phytochemical compounds and measure antioxidant activities. Gas chromatography mass spectrometry analyses identified 22 different phytocompounds in hexane extracts of the different parts of the kenaf plant. The most abundant volatile compounds were E-phytol (32.4%), linolenic acid (47.3%), trisiloxane-1,1,1,5,5,5-hexamethyl-3,3-bis[(trimethylsilyl)oxy] (16.4%), and linoleic acid (46.4%) in leaves, bark, flowers, and seeds, respectively. Ultra-high performance liquid chromatography identified the major compounds in the different parts of the kenaf plant as kaemperitrin, caffeic acid, myricetin glycoside, and p-hydroxybenzoic acid in leaves, bark, flowers, and seeds, respectively. Water extracts of flowers, leaves, and seeds exhibited the greatest DPPH radical scavenging activity and SOD activity. Our analyses suggest that water is the optimal solvent, as it extracted the greatest quantity of functional compounds with the highest levels of antioxidant activity. These results provide valuable information for the development of environmentally friendly natural products for the pharmaceutical industry.

• Food Science and Biotechnology
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• v.16 no.5
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• pp.822-827
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• 2007

The aroma characteristics and antioxidative activity of volatile compounds in heat-treated garlic (Allium sativum L.) were evaluated. The garlic was heated to various temperatures (100, 110, 120, and $130^{\circ}C$) for different lengths of time (1, 2, and 3 hr). The volatile compounds of heated garlic were extracted by simultaneous steam distillation extraction (SDE). Aroma compound profiles were analyzed by gas chromatography/mass spectrometry (GC/MS) and antioxidative activity was measured by 2,2-diphenyl-2-picrylhydrazyl (DPPH) assay and 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) cation decolorization assay. The major aroma compounds were sulfur compounds such as dimethyl disulfide, 2-propen-1-ol, methyl-2-propenyl disulfide, dimethyl trisulfide, diallyl disulfide, methyl-2-propenyl trisulfide, and di-2-propenyl trisulfide. DPPH radical scavenging activity (EDA, %) and the ascorbic acid equivalent antioxidant activity (AEAC) of volatile compounds in heated garlic increased significantly with the increase of temperature and time (p<0.001). The EDA (%) and AEAC of raw garlic were 26.8%/10 mg garlic and 39.05 mg ascorbic acid equivalent per g sample. After heat treatment, the highest values were 40.50%/10 mg garlic for EDA (%) and 46.43 mg ascorbic acid equivalent per g sample for ABTS.

• KSBB Journal
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• v.29 no.3
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• pp.155-164
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• 2014

Succinic acid, a representative biomass-derived platform chemical, is a major fermentation product of Actinobacillus succinogenes. It is well known that carbon dioxide is consumed during the succinate fermentation, but the biochemical mechanism behind this phenomenon is not yet understood well. In this study, it was found that the addition of carbonic anhydrase (CA)s into media significantly enhances the succinic acid production by A. succinogenes during the fermentation supplied with carbon dioxide. It is likely that the (bi) carbonate produced by the CA activity from gaseous carbon dioxide is favoured by A. succinogenes for consumption and utilization. Therefore, the $MgCO_3$ requirement could be significantly reduced without compromising the succinate productivity. Furthermore, because of too high price of the commercial carbonic anhydrase, it was undertaken to economically overproduce a cyanobacterial carbonic anhydrase by the use of a recombinant Pichia pastoris. An expression vector system was constructed with the carbonic anhydrase gene PCR-cloned from Cyanobacterium Synechocystis sp., and introduced into P. pastoris for fermentation studies. About 95.9 g/L of succinic acid was produced in the production medium with 30 ppm of carbonic anhydrase, approximately 2 fold higher productivity compared to the parallel process with no supplementation of the enzyme. It is expected that this method can provide a valuable way of overcoming inefficiencies inherent in gas supply during $CO_2$-based bioprocesses like succinic acid fermentation.

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.385-394
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• 1994

Numerical solutions were obtained to the model equations for various of the parameters characterizing the pore structure, effective internal diffusion, and the chemical reaction constant. The conversion was decreased with the cause of pore closure at the surface of reacting particles, reduction of porosity, surface area of reaction and effective diffusion coefficient in the solid with the progress of reaction. Total conversion was strongly dependent on the local conversion at surface. According to the decreasing of impregnated concentration of the copper oxide and the increase of the flue gases concentration, total conversion was increased. The conversion was affected by gas flow rate and pore size distribution in the reacting solid.

• Applied Biological Chemistry
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• v.25 no.3
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• pp.177-181
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• 1982

This experiment was carried out to investigate the stability of Dicofol solutions which were prepared with various organic solvents such as xylene, toluene, methylisobutyl ketone (M.I.B.K.), cyclohexanone, N.N.-dimetyl formamide (N.N.-D.M.F.) and isophorone under different temperature and storage period. The decomposition rate of Dicofol was increased in the order of cyclohexanone> N.N.-D.M.F.>W.P.>toluene, xylene, M.I.B.K. and isophorone. However, it was shown that precipitation was found in Dicofol solutions such as xylene, toluene and M.I..B.K. except isophorone. Therefore, isophorone was recognized as the best of organic solvents tested for Dicofol in the case of emulsifiable concentrate formulation with it.

• Mycobiology
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• v.45 no.3
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• pp.178-183
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• 2017

Diabetes mellitus is a chronic disorder which affects millions of population worldwide. Global estimates published in 2010 reported the world diabetic prevalence as 6.4%, affecting 285 million adults. Foot ulceration and wound infection are major forms of disabilities arising from diabetic diseases. This study was aimed to develop a natural antimicrobial finishing on medical grade textile that meets American Association of Textiles Chemists and Colorists (AATCC) standard. The textile samples were finished with the ethanolic extract of Penicillium amestolkiae elv609, an endophytic fungus isolated from Orthosiphon stamineus Benth (common name: cat's whiskers). Endophyte is defined as microorganism that reside in the living plant tissue, without causing apparent disease symptom to the host. The antimicrobial efficacy of the ethanolic extract of P. minioluteum was tested on clinical pathogens isolated from diabetic wound. The extract exhibited significant inhibitory activity against 4 bacteria and 1 yeast with the minimal inhibitory concentration ranged from 6.25 to 12.5 mg/mL. The results indicate different susceptibility levels of the test microorganism to the ethanolic extract. However, the killing activity of the extract was concentration-dependent. The finished medical textile showed excellent antimicrobial efficacy on AATCC test assays. All the microbial cultures treated with the textile sample displayed a growth reduction of 99.9% on Hoheinstein Challenge Test. The wash durability of the finished textile was found good even after 50 washes with commercial detergent. Besides, the gas chromatography mass spectrometry analysis showed that 6-octadecenoic acid and diethyl phthalate were the main bioactive constituents of the extract. In conclusion, the developed medical textile showed good antimicrobial efficacy on laboratory tests. This work can be extended to in vivo trials for developing healthcare textile products for antimicrobial applications.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.169-175
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• 2006

Potentiometric biosensor using flow injection analysis system was developed to determine citrate concentration in foods. Biosensor system consisted of sample injector, peristaltic pump, enzyme reactor, carbonate ion selective solid-state electrode, reference electrode, detector, and recorder. Enzyme reactor was prepared with immobilized citrate lyase and oxaloacetate decarboxylase. Carbonate ions produced through enzyme reactions of citrate were potentiometrically detected by ion selective electrode. Optimum conditions for biosensor system were investigated. Interference effect of major sugars and organic acids was less than 5% on citrate biosensor system. Citrate concentrations in fruit juices were determined by biosensor and gas chromatography. No significant difference was observed between two analytical methods. Results indicate citrate biosensor is useful in determining citrate concentration in foods.

• The Korean Journal of Food And Nutrition
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• v.20 no.3
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• pp.245-252
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• 2007

This study investigated the effects of conjugated linoleic acid(CLA) on the fat deposition, triglyceride levels and the expression of stearoyl-CoA desaturase 1(SCD1) in the livers of male ICR mice that were fed with either soybean oil or beef tallow supplemented with CLA. Mice weighing $25{\sim}30$ g were divided into four groups; soybean oil(SBO), and SBO supplemented with 1% CLA(SBOC), beef tallow(BT) and BT supplemented with 1% CLA(BTC). Each group consisted of 10 mice that were fed the experimental diets for 4 weeks. The experimental diets consisted of 64% carbohydrate, 20% protein, and 16% fat in terms of their contributions to total calories. All other nutrients were identical in the diets. Triglyceride measurements were completed using a kit. Fatty acid compositions were analyzed in the liver using gas chromatography. The levels of SCD1 expression were analyzed by RT-PCR in the liver. No significant differences were found for food intake level, body weight and food efficiency among the experimental groups. However, the weights of epididymal fat pads and plasma triglyceride levels were significantly lower in SBOC and BTC(p<0.05) compared to the SBO and BT groups. These effects were similar in the CLA supplemented groups. The expression level of SCD1 gene and ${\Delta}9$ desaturase index were not significantly different, regardless of the fat used for CLA supplementation. Based on these results, addition of CLA showed decreasing effects on the fat depots weight and the concentration of triglyceride regardless of the fat sources. The SCD1 gene expression and ${\Delta}9$ desaturase index were not influenced by the types of fats with respect to the CLA effects.

• Journal of Marine Life Science
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• v.6 no.1
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• pp.1-8
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• 2021

In marine ecosystems, the biosynthesis and catabolism of dimethylsulfoniopropionate (DMSP) by marine bacteria is critical to microbial survival and the ocean food chain. Furthermore, these processes also influence sulfur recycling and climate change. Recent studies using emerging genome sequencing data and extensive bioinformatics analysis have enabled us to identify new DMSP-related genes. Currently, seven bacterial DMSP lyases (DddD, DddP, DddY, DddK, DddL, DddQ and DddW), two acrylate degrading enzymes (DddA and DddC), and four demethylases (DmdA, DmdB, DmdC, and DmdD) have been identified and characterized in diverse marine bacteria. In this review, we focus on the biochemical properties of DMSP cleavage enzymes with special attention to DddD, DddA, and DddC pathways. These three enzymes function in the production of acetyl coenzyme A (CoA) and CO₂ from DMSP. DddD is a DMSP lyase that converts DMSP to 3-hydroxypropionate with the release of dimethylsulfide. 3-Hydroxypropionate is then converted to malonate semialdehyde by DddA, an alcohol dehydrogenase. Then, DddC transforms malonate semialdehyde to acetyl-CoA and CO₂ gas. DddC is a putative methylmalonate semialdehyde dehydrogenase that requires nicotinamide adenine dinucleotide and CoA cofactors. Here we review recent insights into the structural characteristics of these enzymes and the molecular events of DMSP degradation.