• 한국수소및신에너지학회논문집
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• 제27권2호
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• pp.169-175
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• 2016

The electrolyte added the chlorosulfuric acid ($HSO_3Cl$) as an additive was tested for the electrolyte in all-vanadium redox flow battery (VRFB) to increase the thermal stability of electrolyte. The electrolyte property was measured by the CV (cyclic voltammetry) method. The maximum value of a voltage and current density in the electrolyte added $HSO_3Cl$ was higher than that in the electrolyte non-added $HSO_3Cl$. The thermal stability of the pentavalent vanadium ion solution, which was tested at $40^{\circ}C$, increased by adding $HSO_3Cl$. The performances of VRFB using the electrolyte added and non-added $HSO_3Cl$ were measured during 30 cycles of charge-discharge at the current density of $60mA/cm^2$. An average energy efficiency of the VRFB was 72.5%, 82.4%, and 81.6% for the electrolyte non-added $HSO_3Cl$, added 0.5 mol of $HSO_3Cl$, and added 1.0 mol of $HSO_3Cl$, respectively. VRFB using the electrolyte added $HSO_3Cl$ was showed the higher performance than that using the electrolyte non-added $HSO_3Cl$.

• 한국식품영양학회지
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• 제10권1호
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• pp.25-30
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• 1997

Purge와 trap headspace sampler를 사용하여 녹차의 휘발성 성분을 추출, 확인한 후 성분조성을 동시증류추출장치로 추출된 성분가 비교하였다. Headspace법으로는 88개 성분을 확인하였으며 methyl butanal(3.1%), 1-penten-3-ol(5.48%), 2-penten-1-ol(2.89%), hexanal(5.77%), heptanal(2.24%) 등의 비교적 비점이 낮은 성분들과 2,4-heptadienal(4.28%), linalool(2.27%), nonanal(2.06%), 2,6-dimethyl cyclohexanol(2.57%) 및 $\alpha$-pinene(1.52%), caryophyllene(1.70%) 등의 hydrocarbon 화합물, $\beta$-cyclocitral(2.0%), $\alpha$-ionone(2.62%), $\beta$-ionone(2.98%) 같은 carbonyl 화합물이 주요 휘발성 성분으로 확인되었다. SDE법으로는 64개의 성분을 확인하였으며 저비점 성분들보다는 benzyl alcohol(3.79%), linalool(9.52%), terpineol(2.16%), geraniol(2.75%), nerolidol(6.50%) 등의 alcohol 성분들과 $\alpha$-ionone(1.77%), $\beta$-ionone(4.80%), geranyl acetone(1.82%) 등의 ketone 화합물, hexanoic acid(1.45%), nonanoic acid(1.11%) 등의 acid 화합물이 주요 성분으로 확인되었다.

• Applied Science and Convergence Technology
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• 제27권4호
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• pp.75-77
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• 2018

The electrostatic interaction between emerging quantum-confined nanostructures with plasmonic structures is crucial for future biological applications. Water-soluble green fluorescent copper nanoparticles (Cu-NPs) were fabricated. We demonstrate that L-ascorbic acid is considered as a key to precisely control small Cu-NPs and the capability of the surface ligands, while cetyltrimethylammonium bromide is used as a stabilizing agent controls the particle growth, and stabilizes the nanoparticles. Water-soluble green fluorescent Cu-NPs are tunable through modification of the reaction periods.

• Asian-Australasian Journal of Animal Sciences
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• 제27권7호
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• pp.937-945
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• 2014

Green and black tea by-products, obtained from ready-made tea industry, were ensiled at $10^{\circ}C$, $20^{\circ}C$, and $30^{\circ}C$. Green tea by-product silage (GTS) and black tea by-product silage (BTS) were opened at 5, 10, 45 days after ensiling. Fermentation characteristics and nutrient composition, including tannins, were monitored and the silages on day 45 were subjected to in vitro ruminal fermentation to assess anti-nutritive effects of tannins using polyethylene glycol (PEG) as a tannin-binding agent. Results showed that the GTS and BTS silages were stable and fermented slightly when ensiled at $10^{\circ}C$. The GTS stored at $20^{\circ}C$ and $30^{\circ}C$ showed rapid pH decline and high acetic acid concentration. The BTS was fermented gradually with moderate change of pH and acid concentration. Acetic acid was the main acid product of fermentation in both GTS and BTS. The contents of total extractable phenolics and total extractable tannins in both silages were unaffected by storage temperatures, but condensed tannins in GTS were less when stored at high temperature. The GTS showed no PEG response on in vitro gas production, and revealed only a small increase by PEG on $NH_3$-N concentration. Storage temperature of GTS did not affect the extent of PEG response to both gas production and $NH_3$-N concentration. On the other hand, addition of PEG on BTS markedly increased both the gas production and $NH_3$-N concentration at any ensiled temperature. It can be concluded that tannins in both GTS and BTS suppressed rumen fermentation, and tannins in GTS did more weakly than that in BTS. Ensiling temperature for both tea by-products did not affect the tannin's activity in the rumen.

• 한국식품조리과학회지
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• 제4권1호
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• pp.47-52
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• 1988

녹차의 품종, 채엽시기, 가공방법별에 따라 13종류의 한국산 녹차시료를 조제하고 이들 시료의 이화학적 성질을 측정한 결과는 다음과 같다. 1. 수활, 회분, 가용성 고형분 및 조지방 함량은 대체적으로 품종, 차엽의 채취시기 및 가공방법의 상위에 따른 큰 차이점은 나타나지 않았지만 조단백질의 경우에서는 삽목 Yabukida 품종 1번 차의 볶음과 찐 것에서 각각 30.8%, 31.3%이던 것이 2, 3번차로 갈수록 점차 감소하여 4번차의 경우에서는 각각 18.8%, 16.0% 이었다. 이러한 경향은 다른 품종에서도 유사한 경향을 나타내었다. 품종별에 따른 변화도 크게 나타났다. 조섬유에서는 채엽시기에 따라 증가하는 경향을 나타내었다. 2. 표면색도는 볶음 차보다 찐 차가 보다 밝은 녹황색을 띄며 채엽시기가 늦을수록 밝은 황색을 나타내었다. 또한 클로로필함량은 찐 차의 경우가 볶은 차보다 높았고, 채엽시기에 따라 감소의 경향을 보였으나 삽목 Yabukida 4번 차의 경우에서는 증가하였다. 3. 탄닌의 함량은 볶음의 경우 채엽시기가 늦을수륵 증가하였지만 찐 차의 경우 그런 경향이 나타나지 않았으며 theaflavin과 thearubigin 함량은 평균하여 각각 0.07% 및 2.27%이었고 산화중합물비는 평균 0.22이었다. 4. Methylxanthine류에서는 caffeine이 주성분으로 94∼98%를 차지하였으며 볶음차의 caffeine 함량이 높았다. 베니호마래의 caffeine 함량은 다른 품종보다 낮았다. 5. 녹차의 환원당은 0.1% 내외로 거의 일정하였으며 유리당의 경우 삽목 Yabukida가 다른 품종에 비해서 sucrose 함량이 높게 나타났다. 6. 녹차중의 유기산은 succinic, malic, shikimic, citric, quinic, gallic, oxalic 및 malonic acid의 8종류이었으며 이중 quinic acid의 함량이 높았다. 삽목 Yabukida 품종에서는 채엽시기가 빠른 녹차에서는 malic acid 함량이 매우 낮은 반면 oxalic acid는 채엽시기가 늦을수록 감소하여 미량으로 검지되었다.

• KSBB Journal
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• 제27권3호
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• pp.151-156
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• 2012

Lactic acid is an important product arising from the anaerobic fermentation by lactic acid bacteria (LAB). It is used in the pharmaceutical, cosmetic, chemical, and food industries as well as for biodegradable polymer and green solvent production. The poly lactic acid (PLA) is an important material for bio-plastic manufacturing process. For PLA production by new LAB, we screened LAB isolates from shellfish. A total of 28 LAB were isolated from various shellfishes. They were all Gram positive, oxidase and catalase negative. Based on API 50CHL kit, 7 strains among the 28 isolates were identified as Lactobacillus plantarum, 6 strains as Lactobacillus delbrueckii, 5 strains as Leuconostoc mesenteroides, 3 strains as Lactobacillus brevis, 2 strains as Lactococcus lactis, 1 strain as Lactobacillus salivarius, 1 strain as Lactobacillus paracasei, 1 strain as Lactobacillus pentosus, 1 strain as Lactobacillus fermentum and 1 strain as Pediococcus pentosaceu. Also, we examined the amount of total lactic acid produced by these new strains by HPLC analysis with Chiralpak MA column. One strain E-3 from Mytilus edulis was indentified as Lactobacillus plantarum and found to produce 20.0 g/L of D-form lactic acid from 20 g/L of dextrose. Further studies are underway to increase the D-lactic acid production by E-3.

• 한국식품조리과학회지
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• 제27권5호
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• pp.567-575
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• 2011

본 연구에서는 한국 전통차(장미차, 감국차, 솔잎차, 감잎차, 뽕잎차 및 녹차)의 총 폴리페놀 및 플라보노이드 함량, 전자공여능, 아질산염 소거능 및 항균효과에 대하여 비교, 조사하였다. 장미차, 감국차, 솔잎차, 뽕잎차, 감잎차 및 녹차 추출물의 총 폴리페놀 함량은 각각 272.8, 74.6, 153.5, 73.5, 69.5 및 260.8 mg/g이었으며, 총 flavonoid 함량은 각각 75.1, 47.8, 26.8, 40.0, 27.9 및 99.5 mg/g이었다. 장미차, 감국차, 솔잎차, 뽕잎차, 감잎차 및 녹차 추출물(1 mg/mL)에 대한 전자공여능은 각각 96.8, 35.8, 71.3, 28.9, 28.8 및 95.3%이었다. pH 1.2에서의 아질산염 소거능(2 mg/mL)은 녹차(91.3%) > 장미차(49.6%) > 솔잎차(46.0%) > 감국차(15.4%) ${\qeq}$ 뽕잎차(14.2%) ${\qeq}$ 감잎차(13.5%)의 순이었다. SOD 유사활성능(5 mg/mL)은 녹차(18.7%) > 장미차(14.7%) > 뽕잎차(14.0%) > 솔잎차(11.2%) > 국화차(8.4%) ${\qeq}$ 감잎차(7.9%)의 순으로 녹차 추출물이 가장 높았으며, 국화차 및 감잎차 추출물은 거의 없었다. 장미차, 감국차, 솔잎차, 뽕잎차, 감잎차 및 녹차 추출물(5 mg/mL)의 hydroxyl radical 소거능은 각각 55.3, 64.4, 35.3, 51.5, 44.6, 29.5%이었다. 장미차의 경우 Micrococcus luteus, Bacillus cereus, Salmonella enteritidis, E. coli 모두에 대해 항균효과를 보였으며, 특히, Gram 음성균인 Salmonella enteritidis에 대해 강한 항균력을 보였다. 녹차, 솔잎의 경우 Salmonella enteritidis, Bacillus cereus에 대해 항균력을 나타내었다. 그러나 뽕잎, 감잎, 국화차의 경우는 Micrococcus luteus, Bacillus cereus, Salmonella enteritidis, E. coli 모두에 대해 항균효과를 보이지 않았다.

• Journal of Microbiology and Biotechnology
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• 제27권1호
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• pp.101-111
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• 2017

The task of improving a fungal strain is highly time-consuming due to the requirement of a large number of flasks in order to obtain a library with enough diversity. In addition, fermentations (particularly those for fungal cells) are typically performed in high-volume (100-250 ml) shake-flasks. In this study, for large and rapid screening of itaconic acid (IA) high-yielding mutants of Aspergillus terreus, a miniaturized culture method was developed using 12-well and 24-well microtiter plates (MTPs, working volume = 1-2 ml). These miniaturized MTP fermentations were successful, only when highly filamentous forms were induced in the growth cultures. Under these conditions, loose-pelleted morphologies of optimum sizes (less than 0.5 mm in diameter) were casually induced in the MTP production cultures, which turned out to be the prerequisite for the active IA biosynthesis by the mutated strains in the miniaturized fermentations. Another crucial factor for successful MTP fermentation was to supply an optimal amount of dissolved oxygen into the fermentation broth through increasing the agitation speed (240 rpm) and reducing the working volume (1 ml) of each 24-well microtiter plate. Notably, almost identical fermentation physiologies resulted in the 250 ml shake-flasks, as well as in the 12-well and 24-well MTP cultures conducted under the respective optimum conditions, as expressed in terms of the distribution of IA productivity of each mutant. These results reveal that MTP cultures could be considered as viable alternatives for the labor-intensive shake-flask fermentations even for filamentous fungal cells, leading to the rapid development of IA high-yield mutant strains.

• Journal of Applied Biological Chemistry
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• 제65권3호
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• pp.129-142
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• 2022

새싹인삼은 잎부터 뿌리까지 섭취가 가능하며 스마트 팜 또는 식물공장에서 재배 시 계절에 영향을 받지 않으며 농약을 사용하지 않아도 되는 이점이 있다. 본 연구에서는 새싹인삼의 최적 재배 시기를 확인하고 영양성분과 항산화 활성을 비교 분석하였다. 생육 시기에 따른 지방산과 무기질 함량은 큰 차이를 보이지 않았다. 총 아미노산 함량은 45일까지 약간 감소하였고 이후에는 증가하였으며 생육 65일 arginine 함량은 3309.11 mg/100 g으로 가장 높게 확인되었다. 총 ginsenoside 함량은 생육기간 동안 큰 변화가 없었다(25일 29.83 mg/g→45일 32.77 mg/g→65일 26.02 mg/g). Ginsenoside Rg2 (0.62 mg/g), Re (8.69 mg/g), Rb1 (4.75 mg/g) 및 Rd (3.47 mg/g)의 함량은 생육기간 중 45일에 가장 높았다. Phenolic acids와 flavonols 함량은 생육 45일 (338.6 및 1277.14 ㎍/g)까지 증가 후 65일까지 감소하였다. Phenolic acids와 flavonols의 주요 화합물은 각각 benzoic acid (99.03-142.33 ㎍/g)와 epigallocatechin (416.03-554.64 ㎍/g)로 확인되었다. DPPH (44.27%), ABTS (75.16%)와 hydroxyl (63.29%) 라디칼 소거활성 및 FRAP 환원력(1.573 OD_573nm) 또한 총 phenolics 및 총 flavonolids 함량과 마찬가지로 생육 45일에 가장 높은 활성을 보였다.

• Journal of Microbiology and Biotechnology
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• 제27권2호
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• pp.306-315
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• 2017

Metabolic engineering with a high-yielding mutant, A. terreus AN37, was performed to enhance the production of itaconic acid (IA). Reportedly, the gene cluster for IA biosynthesis is composed of four genes: reg (regulator), mtt (mitochondrial transporter), cad (cis-aconitate decarboxylase), and mfs (membrane transporter). By overexpressing each gene of the IA gene cluster in A. terreus AN37 transformed by the restriction enzyme-mediated integration method, several transformants showing high productivity of IA were successfully obtained. One of the AN37/cad transformants could produce a very high amount of IA (75 g/l) in shake-flask cultivations, showing an average of 5% higher IA titer compared with the high-yielding control strain. Notably, in the case of the mfs transformants, a maximal increase of 18.3% in IA production was observed relative to the control strain under the identical fermentation conditions. Meanwhile, the overexpression of reg and mtt genes showed no significant improvements in IA production. In summary, the overexpressed cis-aconitate decarboxylase (CAD) and putative membrane transporter (MFS) appeared to have positive influences on the enhanced IA productivity of the respective transformant. The maximal increases of 13.6~18.3% in IA productivity of the transformed strains should be noted, since the parallel mother strain used in this study is indeed a very high-performance mutant that has been obtained through intensive rational screening programs in our laboratory.