• 한국미생물·생명공학회지
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• 제9권1호
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• pp.45-50
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• 1981

Adenine-guanine 동시영양요구성인 Brevibacterium ammoniagenes D-21530을 사용하여 5'-IMP을 생산할 경우, 5'-IMP생성에는 탄소원으로 fructose가 glucose보다 효율적이었다. 반면에 균 생육에는 glucose를 탄소원으로 사용하는 것이 좋았다. Glucose와 fructose를 혼합하여 사용할 때 균 생육을 적절히 조절하여 5'-IMP축적을 증가시켜 줄 수 있었으며 fructose와 glucose의 혼합당에 있는 fructose의 함유율을 20∼40%범위로 하였을 때 5'-IMP생성이 최대가 되었고 fructose 단독으로 사용할 때보다 약 40% 증가되었다. 또한 영양요구성물질인 adenine과 guanine의 첨가농도가 증가함에 따라 균생육이 촉진되나 150㎎/l 이상에서는 정상상태였고, 5'-IMP생성은 50㎎/l 까지는 첨가 농도에 따라 급격히 증가하나 그 이상에서는 감소하였다.

• 한국작물학회지
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• 제49권1호
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• pp.52-60
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• 2004

The optimized in vitro culture system was investigated for improvement of regeneration efficiencies by observing the responses of scutella-derived callus of Korean rice (Oryza sativa L.). Large variations of callus induction (43.9-93.9%) and shoot regeneration (0-88.7%) were observed among the rice cultivars depending on medium. However, shoot regeneration was significantly improved by selected utilization of basal medium, growth regulators, and carbon sources. N6 basal medium was more efficient for embryogenic callus induction than MS or LS basal medium, while MS was superior to N6 for shoot regeneration. The calli of highly regenerative cultivars grew faster and showed higher rates of green tissue formation (GT) and shoot regeneration (SR) and lower rate of callus browning (CB) than those of recalcitrant cultivars. Although a higher level of kinetin stimulated the GT and SR in highly regenerative cultivars, $10\textrm{mgL}^{-1}$ kinetin generally suppressed the GT and SR, while CB was accelerated compared to $2\textrm{mgL}^{-1}$ kinetin. Additional benefits of sorbitol combined with maltose (or sucrose) under $5\textrm{mgL}^{-1}$ kinetin were certainly confirmed on regeneration efficiencies compared to sucrose alone as carbon source and osmotic regulator. This combination showed high rate of GT and SR with multiple shoots while low rate of CB. With MSRK5SM-Pr medium ($5\textrm{mgL}^{-1}$ kinetin, 3% sorbitol, 2% maltose, $500\textrm{mgL}^{-1}$ proline), the regeneration efficiencies of total 17 out of 24 cultivars were practically improved 160% on average compared to MSRK2S ($2\textrm{mgL}^{-1}$ kinetin, 3% sucrose) control medium. Especially, the medium was most effective to the cultivars showing a medium level of regenerability such as Daesanbyeo and Dongjinbyeo and Suwon477, enhancing efficiencies more than 300-600% compared to MSRK2S medium.

• Journal of Microbiology and Biotechnology
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• 제23권6호
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• pp.794-801
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• 2013

This paper reports the production and characterization of crude xylanase from the newly isolated Humicola sp. Ly01. The highest (41.8 U/ml) production of the crude xylanase was obtained under the optimized conditions (w/v): 0.5% wheat bran, 0.2% $KH_2PO_4$, and 0.5% peptone; initial pH 7.0; incubation time 72 h; $30^{\circ}C$; and 150 rpm. A considerable amount of the crude xylanase was induced using hulless barley bran or soybean meal as the carbon source, but a small amount of the enzyme was produced when supplementary urea was used as the nitrogen source to wheat bran. The crude xylanase showed apparent optimal cellulase-free xylanase activity at $60^{\circ}C$ and pH 6.0, more than 71.8% of the maximum xylanase activity in 3.0-30.0% (v/v) ethanol and more than 82.3% of the initial xylanase activity after incubation in 3.0-30.0% (v/v) ethanol at $30^{\circ}C$ for 2 h. The crude xylanase was moderately resistant to both acid and neutral protease digestion, and released 7.9 and 10.9 ${\mu}mol/ml$ reducing sugar from xylan in the simulated gastric and intestinal fluids, respectively. The xylooligosaccharides were the main products of the hydrolysis of xylan by the crude xylanase. These properties suggested the potential of the crude enzyme for being applied in the animal feed industry, xylooligosaccharides production, and high-alcohol conditions such as ethanol production and brewing.

• 한국균학회지
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• 제42권2호
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• pp.150-158
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• 2014

4종의 외생균근균이 MMN 배지상에서 7종 단소원에 대한 이용능력을 조사하였다. 60일간 순수배양한 결과, 다색벚꽃버섯(KFRI 1987), 향버섯, 접시껄껄이그물버섯(KFRI 1194), 송이(KFRI 1256)는 dextrin에서 균사 생장이 우수하였다. 다색벚꽃버섯, 향버섯(KFRI 1676), 접시껄껄이그물버섯은 pectin에서 균사 생장이 가장 낮았다. 송이(KFRI 1256)를 제외한 7개의 균주들은 heteroglycan(pectin)보다 homoglycan계 탄소원(starch, dextrin)의 이용률이 더 높은 것으로 조사되었다. 균 배양 후 배지의 pH 값은 배양 전보다 최소 1.1~최대 3.0 범위까지 감소하였다. 외생균근균 배양체의 형태적 특징을 조사한 결과, 모든 탄소원 시험배지에서 백색 균사체가 우세하였으나 탄소원의 종류에 따라 황색, 갈색, 자주색 계열의 다양한 균사체가 관찰되었다. 접시껄껄이그물버섯은 4~5종류의 탄소원에서 single colony의 형태로 생장한 반면, 이외 대부분의 균주들은 6종의 탄소원에서 multiple colony의 형태로 생장하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.683-686
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• 2004

In recent years, the supercapacitor and hybrid capacitor have related with substitutional energy source focused of many scientists because of their usage in power sources for electric vehicles, computers and other electric devices. The storage energy of electrical charge is based on electrostatic interactions in the electric double layer at the electrode/electrolyte interface, resulting in high rate capability and long cycle performance compared with batteries based on Faradaic electrode reactions. So we have been considered to carbon nanofibers as the ideal material for supercapacitors due to their high utilization of specific surface area, good conductivity, chemical stability and other advantages. In this work, we aimed to find out that the capacitance have increased because of electrochemical capacitance to provide by carbon nanofibers. Also carbon nanofibers based on chemical method and water treatment have been resulted larger capacitances and also exhibit better electrochemical behaviors about 15% than before of nontreated state. And also optical observations with treated and nontrteated carbon nanofibers discussed by the TEM, SEM, EDX, BET works and specific surface area analyzer. Their results also focused on the surface area of electrode and electrical capacitance was also improved by the effect of surface treatments.

• 한국수소및신에너지학회논문집
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• 제33권6호
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• pp.845-855
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• 2022

In response to climate change, the world is continuing efforts to reduce fossil fuels, expand renewable energy, and improve energy efficiency with the goal of achieving carbon neutrality. In particular, R&D is being made on the value chain covering the entire cycle of hydrogen production, storage, transportation, and utilization in order to shift the energy supply system to focus on hydrogen energy. Hydrogen-based energy sources can produce heat and electricity at the same time, so it is possible to utilize heat energy, which can increase overall efficiency. In this study, calculation of the optimal scale for hydrogen-based cogeneration and the composition of heat sources were reviewed. It refers to a method of the optimal heat source size according to the external heat supply and heat storage to be considered. The results of this study can be used as basic data for establishing a hydrogen-based energy supply model in the future.

• Journal of Microbiology and Biotechnology
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• 제3권2호
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• pp.115-122
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• 1993

Poly(3-hydroxybutyrate)(P(3HB)) accumulation under nutrient-rich condition with various amounts of $(NH_4)_2 SO_4$ was systematically investigated. The results of the electron-microscopy and the solvent extraction showed that the P(3HB) accumulation is unavoidable even under nutrient-rich condition. This indicates that in a two-step culture of Alcaligenes eutrophus H16, the researches should be careful in interpreting the data of polyhydroxyalkanoates(PHAs) accumulation in terms of the carbon-source fed in the second step because the two-step culture product contains the P(3HB) produced under nutrient-rich condition. The polyester production capability in a two-step batch culture of A. eutrophus H16(ATCC 17699) was also investigated using various saccharides and their derivatives such as glucose, fructose, gluconic acid, glucaric acid, sorbitol, lactose, galactose, and mannose. The polyesters synthesized were characterized by 500 MHz$^{1}H-NMR$ spectroscopy, intrinsic viscosity$[\eta]$ measurement in chloroform and differential scanning calorimetry(DSC). 500 MHz $^{1}H-NMR$ analysis showed that all polyesters synthesized generally contained 1~2 mol% of 3HV. Another finding is that the glucose utilization can be increased by changing the autoclaving procedure of the substrate to enhance the P(3HB) production yield up to 46 wt% of P(3HB) in dry cells.

• 신재생에너지
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• 제4권2호
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• pp.21-30
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• 2008

Anaerobic digestion (AD) is the most promising method of treating and recycling of different organic wastes, such as OFMSW, household wastes, animal manure, agro-industrial wastes, industrial organic wastes and sewage sludge. During AD, i.e. degradation in the absence of oxygen, organic material is decomposed by anaerobes forming degestates such as an excellent fertilizer and biogas, a mixture of carbon dioxide and methane. AD has been one of the leading technologies that can make a large contribution to producing renewable energy and to reducing $CO_2$ and other GHG emission, it is becoming a key method for both waste treatment and recovery of a renewable fuel and other valuable co-products. A classification of the basic AD technologies for the production of biogas can be made according to the dry matter of biowaste and digestion temperature, which divide the AD process in wet and dry, mesophilic and thermophilic. The biogas produced from AD plant can be utilized as an alternative energy source, for lighting and cooking in case of small-scale, for CHP and vehicle fuel or fuel in industrials in case of large-scale. This paper provides an overview of the status of biogas production and utilization technologies.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.202-205
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• 2008

Anaerobic digestion(AD) is the most promising method of treating and recycling of different organic wastes, such as OFMSW, household wastes, animal manure, agro-industrial wastes, industrial organic wastes and sewage sludge. During AD, i.e. degradation in the absence of oxygen, organic material is decomposed by anaerobes forming degestates such as an excellent fertilizer and biogas, a mixture of carbon dioxide and methane. AD has been one of the leading technologies that can make a large contribution to producing renewable energy and to reducing $CO_2$ and other GHG emission, it is becoming a key method for both waste treatment and recovery of a renewable fuel and other valuable co-products. A classification of the basic AD technologies for the production of biogas can be made according to the dry matter of biowaste and digestion temperature, which divide the AD process in wet and dry, mesophilic and thermophilic. The biogas produced from AD plant can be utilized as an alternative energy source, for lighting and cooking in case of small-scale, for CHP and vehicle fuel or fuel in industrials in case of large-scale. This paper provides an overview of the status of biogas production and utilization technologies.

• 한국지반환경공학회 논문집
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• 제5권4호
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• pp.25-31
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• 2004

일반 활성슬러지 공정에서 유입수의 COD 분율은 매우 중요한 인자이다. 강화된 수질기준의 준수를 위해서는 유입수내 COD 분율화에 기초한 활성슬러지 공정의 주요 운영조건 변화가 요구된다. 본 연구에서는 이분해성 COD와 천천히 분해되는 COD의 대표 구성물질로써 글루코스와 펩톤을 이용하여 기지농도의 합성폐수를 조제하였으며, 산소이용율(OUR)과 질산성질소 이용율(NUR)을 이용하여 기지의 농도로 제조된 합성폐수에 대해 기존 COD 분율화 방법활용시 결과예측의 정확성 검증과 평가에 관한 실험을 수행하였다. OUR 실험의 경우, 기지의 농도로 제조된 합성폐수와 일치되는 결과를 얻을 수 있었으나 NUR 실험의 경우, 유입수 분율화에 오차가 발생하는 것으로 나타났다. 이와 같은 오차는 인축적 미생물(PAOs)와 같은 저장 미생물의 내부저장기작에 의한 결과로써 유입수 분율화에 최대 8-14 %의 오차를 유발하는 것으로 나타났다.