• KSBB Journal
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• 제4권2호
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• pp.78-86
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• 1989

에너지소모를 최소화하고 최대의 당화효과를 얻을 수 있는 고효율 당화장치의 개발을 목표로 impeller교반형 bioattritor를 설계, 제작하여 불용성 섬유소를 기질로 실험하였다. Bioattrotor의 효용성과 효소당화촉진 mechan-ism을 규명하였으며, 최적운전조건을 검토하였다. 분쇄 마찰매체함유 반응기에 일정한 탄성계수를 지닌 spiral spring coil을 내장한 torzue측정장치를 개발, 부하되는 torque, power, 그리고 소요에너지를 측정하여 이를 당화촉진과 비교함으로서 bioattritor의 경제성을 검토하였다. 분쇄마찰매체의 첨가량 및 종류, impeller형태, 교반속도는 중요한 요소로서 작용하였다. 비록 더 연구가 필요하나 분쇄마찰매체의 교반에 소모되는 동력은 당화 촉진효과의 증대에 따른 당화시간의 단축과 섬유소의 고효율 전환에 따른 고농도당의 확보등에 의해 보상되리라 예상된다.

• KSBB Journal
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• 제28권6호
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• pp.366-371
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• 2013

Ethanol productions were performed by separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) processes using seaweed, Enteromorpha intestinalis (sea lettuce). Pretreatment conditions were optimized by the performing thermal acid hydrolysis and enzymatic hydrolysis for the increase of ethanol yield. The pretreatment by thermal acid hydrolysis was carried out with different sulfuric acid concentrations in the range of 25 mM to 75 mM $H_2SO_4$, pretreatment time from 30 to 90 minutes and solid contents of seaweed powder in the range of 10~16% (w/v). Optimal pretreatment conditions were determined as 75 mM $H_2SO_4$ and 13% (w/v) slurry at $121^{\circ}C$ for 60 min. For the further saccharification, enzymatic hydrolysis was performed by the addition of commercial enzymes, Celluclast 1.5 L and Viscozyme L, after the neutralization. A maximum reducing sugar concentration of 40.4 g/L was obtained with 73% of theoretical yield from total carbohydrate. The ethanol concentration of 8.6 g/L of SHF process and 7.6 g/L of SSF process were obtained by the yeast, Saccharomyces cerevisiae KCTC 1126, with the inoculation cell density of 0.2 g dcw/L.

• Journal of Microbiology and Biotechnology
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• 제2권3호
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• pp.197-203
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• 1992

Studies of the pretreatment of chitin and its subsequent hydrolysis by Aspergillus carneus chitinase are reported. Ball milling was found to be the most effective way among the pretreatment methods tested. Data are presented describing the effect of enzyme and substrate concentrations on the rate and extent of the hydrolysis process. It was found that the successive addition of enzyme improved the saccharification yield. Significant product inhibition of the chitinase was observed when N-acetylglucosamine concentration was 3.6％ or higher. Adsorption of enzymes to the substrate occurred during a 24 hr hydrolysis period. An initial rapid and extensive adsorption occurred, followed by gradual desorption which increased during the time of reaction. Intermediate removal of the hydrolyzate and continuation of the hydrolysis by adsorbed enzyme on the residual chitin was also investigated. A total of 75.4 g/l reducing sugars, corresponding to 69.2％ saccharificaton yield (as N-acetylglucosamine) was obtained. In addition an increase in the amount of recoverable enzymes was observed under these conditions. Evidence presented here suggests that the technique, whereby the free enzymes in the recovered hydrolyzate are re-adsorbed onto the new substrate, may provide a means of recirculating the dissolved enzymes.

• Food Science and Biotechnology
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• 제14권5호
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• pp.651-655
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• 2005

Enzymatic hydrolysis of shark (Squatina oculata) cartilage (SC) was optimized by response surface methodology (RSM) for chondroitin sulfate (CS) preparation. Among 11 commercial proteases, Maxazyme NNP showed highest productivity (CS yield per enzyme cost) of CS. Optimal hydrolysis conditions determined by RSM were 1.63% and 2.87 hr for enzyme concentration and hydrolysis time ($r^2\;=\;0.9527$, p<0.0l), respectively and highest yield of hydrolysate under the conditions was 42.3%. The yield ($43.1{\pm}2.1%$) and CS content ($24.8{\pm}0.1%$) of hydrolysate at optimal condition verified statistical optimization of SC enzymatic hydrolysis was valid.

• 한국식품영양학회지
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• 제10권1호
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• pp.87-91
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• 1997

식혜에 함유된 이소말토올리고당과 밥알에 30unit/ml의 $\alpha$-아밀라아제, 글루코아밀라아제, $\alpha$-글루코시다아제, $\beta$-아밀라아제를 가하여 작용시킨 결과 글루코아밀라아제 외에는 일부밖에 가수분해하지 못하였다. 그리고, 인체의 효소인 $\alpha$-아밀라아제와 $\alpha$-글루코시다아제를 함께 작용시켜도 25% 이상 가수분해하지 못하므로 비피두스균의 활성인자로 작용할 것으로 보인다. 밥알은 물에 녹지 않기 때문에 식이섬유로도 작용할 것으로 보인다.

• Journal of the Korean Wood Science and Technology
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• 제41권2호
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• pp.87-99
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• 2013

Waste paper stands for the major biodegradable organic fraction of most of municipal solid waste. The potential of waste paper for glucose production was investigated in this current work. The pretreatment was accomplished by first subjecting waste paper to disintegration time (30 s), followed by ink removal of disintegrated waste paper using an deinking agent. Concentrated acid hydrolysis of waste paper with sulfuric acid was optimized to maximize glucose conversion. The concentrated acid hydrolysis conditions for waste paper (disintegrated time: 30 s, deinking agent loading : 15 ml) were optimized by using central composite design and response surface methodology. The optimization process employed a central composite design, where the investigated variables were acid concentration (60~80%), loading sulfuric acid (1~5 ml) and reaction time (1~5 h). All the tested variables were identified to have significant effects (p < 0.05) on glucose conversion. The optimum concentrated acid hydrolysis conditions were acid concentration of 70.8%, loading sulfuric acid of 3.2 ml and a reaction time of 3.6 h. This research of concentrated acid hydrolysis was a promising method to improve glucose conversion for waste paper.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.485-488
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• 2006

In order to investigate the possibility of waste mushroom logs as biomass resource chemical and physical characteristics of normal woods and waste mushroom logs such as crystallinity value, energy consumption, total sugar yield after hydrolysis chemical compounds and molecular weight distribution after acid hydrolysis, were examined. In the results, crystallinity of waste mushroom logs which were three year passed after the inoculation was decreased drastically from 49% to 33% during the cultivation. Lignin contents as chemical compounds of normal woods and waste mushroom logs were 21.07% and 18.78%, respectively. By the results of measurement of energy consumption, the size reduction of normal woods required a significantly higher energy than that of waste mushroom logs. In the hydrolysis, total sugar yield by enzyme and acid hydrolysis were high in waste mushroom logs(53% 57.5%) than in normal woods(42.9%, 47.17%). According to the molecular weight distribution using GPC, low molecular weight compounds were distributed in waste mushroom logs. Based on these results, waste mushroom logs have enough potential as material for developing alternative energy because of easily conversion to sugar by various hydrolysis methods and requirement of low energy consumption during size reduction.

• Weed & Turfgrass Science
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• 제2권2호
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• pp.176-183
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• 2013

담수조류인 그물말 (Hydrodictyon reticulatum, HR)의 실용적 당화조건 확립을 위해 산 가수분해 방법으로서 one-step acid hydrolysis과 two-step acid hydrolysis, 그리고 산가수분해 후 효소가수분해를 병행하는 combined hydrolysis를 검토하였다. One-step acid hydrolysis의 경우, $120^{\circ}C$에서 HR 4% 고형분을 2% 황산 용액에 넣어 1시간 동안 반응시킬 경우가 적정하였다. Two-step acid hydrolysis의 적정조건은 1차 가수분해시 HR 건조중: 72% 황산을 1 g : 1.5mL로 하여 $60^{\circ}C$에서 1시간 반응시킨 다음, 증류수 23.5 mL를 첨가하고 $120^{\circ}C$에서 1시간 가수분해시키는 것이었다. Combined hydrolysis의 경우, 2% 염산에 25%의 HR 고형분을 넣고 $120^{\circ}C$에서 1시간 반응시킨 후, citrate buffer로 4% 고형분 함량이 되도록 희석하고 E1+E2 효소를 각각 1+0.2 mL g $DM^{-1}$ 수준으로 첨가하여 $50^{\circ}C$에서 1~2일 동안 반응시키는 것이 바람직하였다. Glucose 생성량, 발효억제물질(HMF, furfural) 생성량, 강산 사용제한 등을 종합적으로 감안할 때, combined hydolysis가 보다 유용할 것으로 판단되었다.

• KSBB Journal
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• 제20권2호
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• pp.106-111
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• 2005

물고기 기름을 구성하고 있는 15종류 지방산에 대한 mol수와 가수분해 시간 사이의 함수관계를 대수함수식, $S_i=-{\alpha_i}1n(t)+{\beta_i}$로 나타내었다. 동일 가수분해 시간에서 각 지방산에 대한 대수함수식의 $S_i$ 값과 실측치 사이의 오차가 15 종류 지방산 모두에 대하여 $5\%$ 이내에 분포되었다. 각 지방산의 mol수 $S_i$와 가수분해 시간 사이의 대수함수식으로부터 각 지방산에 대한 가수분해 반응속도를 지방산 mol 수의 지수함수 관계식, $v_i={\gamma_i}exp(\frac{S_i}{\alpha_i})$로 유도하였다. 또한 유도된 $S_i$와 t 사이의 함수관계식으로부터 물고기 기름을 구성하는 15 종류 지방산 각각에 대한 가수분해율을 분석하였다. 가수분해 시간 48시간에서 가수분해율이 $70\%$ 이상인 지방산은 C14:0, C16:0, C18:0, C16:1, C18:1(n-7) 및 Cl8:1(n-9)이였으며, 가수분해율이 $40\%$ 내지 $60\%$ 사이에 분포되어 있는 지방산은 C20:1, C22:1, C18:3, C18:4, C20:4 및 C20:5이였으며, 가수분해율이 $30\%$ 내외인 지방산은 C2l:5와 C22:5이였으며, $20\%$ 이하인 지방산은 C22:6이였다.

• Journal of the Korean Wood Science and Technology
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• 제37권6호
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• pp.578-584
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• 2009

백합나무 목분으로 고농도 단당류를 생산하기 위하여 진한 황산을 사용하는 산 가수분해 특성을 연구하였다. 목분과 황산의 비율을 달리하거나 2차 가수분해의 온도와 시간을 달리하여 당화액 제조의 최적 조건을 탐구한 결과, 1차 가수분해의 목분과 72% 황산 비율은 1 : 2.61(w/w)였으며, 2차 가수분해 온도와 시간은 $105^{\circ}C$에서 70분 가수분해 조건이었다. 이때 생성된 당화액의 농도는 glucose가 44.8 g/L였고 xylose는 25.2 g/L였다. 산 가수분해를 통하여 얻어진 당화액을 발효할 때 발효 저해물질로 알려진 furfural, 5-HMF (5-hydroxymethylfurfural), 저분자량 페놀성 화합물들이 생성되었는데 furfural과 5-HMF는 2차 가수분해 온도가 높아짐에 따라, 그리고 반응시간이 길어짐에 따라 생성량이 증가하였다. $110^{\circ}C$ 2차 가수분해 조건에서 반응시간이 40분을 지남에 따라서 xylose농도는 감소하였고 glucose 농도는 일정하였는데, xylose는 생성속도보다 furfural로 전이 속도가 더 빠른 것으로 생각되고, glucose의 경우 생성속도와 5-HMF로 전이속도가 비슷하여 농도가 일정하게 나타났다.