• ALGAE
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• 제18권1호
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• pp.71-81
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• 2003

• 공업화학
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• 제26권4호
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• pp.511-514
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• 2015

차세대 바이오에탄올로 주목받고 있는 목질계 바이오매스를 이용한 셀룰로오스 에탄올 생산과정은 셀룰로오스를 단당류로 분해하는 전처리과정이 가장 중요한 역할을 한다. 본 연구에서는 산가수분해와 효소당화과정을 이용하여 볏짚, 톱밥, 복사지, 신문지 등과 같은 목질계 바이오매스로부터 셀룰로오스에탄올을 제조하였다. 전처리과정으로 10~30 wt% 황산을 이용한 산가수분해($100^{\circ}C$, 1 h), celluclast ($55^{\circ}C$, pH = 5.0), AMG ($60^{\circ}C$, pH = 4.5), spirizyme ($60^{\circ}C$, pH = 4.2)을 이용한 효소당화과정(30 min), 산가수분해 후 효소당화과정을 비교하였다. 전처리과정의 수율은 hybrid 과정 > 산가수분해 > 효소당화 순으로 셀룰로오스 에탄올로의 전환이 잘 이루어지는 것으로 나타났으며, 최적 발효시간은 2일이었다. 또한 20 wt% 황산을 이용한 산가수분해 후 celluclast를 이용하여 효소당화를 수행할 경우 톱밥 > 볏짚 > 복사지 > 신문지 순으로 셀룰로오스 에탄올 전환특성이 높게 나타났다.

• 펄프종이기술
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• 제41권1호
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• pp.61-66
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• 2009

Effects of aqueous ammonia soaking treatments to yellow poplar (Liriodendron tulipifera L.) were investigated to focus on chemical compositional changes and enzymatic hydrolysis characteristics changes by this treatment. Treatment temperature and time were main variables. At 3 different levels of aqueous ammonia soaking temperature and time ($145^{\circ}C$ -1 h, $90^{\circ}C$ -16 h and $45^{\circ}C$ - 6 days), lower temperature and longer soaking time led to more xylan removal based on carbohydrate compositional analysis. However, at higher temperature treatment led to more enzymatic saccharification of cellulose to glucose by commercial cellulose mixtures (Celluclast 1.5L and Novozym 342 from Novozyme, Denmark). Cellulose hydrolysis was gradually increased with increasing enzymatic hydrolysis time but xylan hydrolysis was leveled out at early stage (less than 10 h) of enzymatic hydrolysis.

• 미생물학회지
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• 제9권4호
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• pp.155-162
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• 1971

A comparison of dextrinogenic amylase activities in the Asp. niger group was made with their crude and ethanol dialized enzymes before and after heating at high temperature (60-$65^{\circ}C$). The results obtained are as follows ; 1. THe dextrinogenic amylase activity of crude enzymes of Asp. kawachii and Asp. foetidus was strong, but Asp. phoernicis, Asp. carbonarius and Asp.japonicus showed weak activity. The others showed medial grades of activity. 2. The ethanol dialized enzymes of Asp. kawachii, Asp. foetidus and Asp. japonicus was very sesitive to high temperature (60 or $65^{\circ}C$) and their enzymatic activities were diminished greatly. The others did not show diminution of enzymatic activity at 60 or 65.deg.C, but diminished greatly at 70 or $75^{\circ}C$. 3. The ethanol dialized enzymes of the Asp.niger group heated to 65.deg.C was more sensitive at pH 6.0 and 6.5 than at pH 4.5, 5.0 and 5.5. 4. Tested strains in the Asp.niger group were subdivided into 4 subgroups by their dextrinogenic amylase activities before and after heating at 60 or $65^{\circ}C$. The first group showed a medial grade of activity before heating and no diminution of their enzymatic activities after heating. Asp. niger, Asp.pulverulentus, Asp. awamori and Asp. usmii were included in this group. The second group had strong enzymatic activity before heating, but diminished greatly after heating. Asp rawachii and Asp. phoenicis were included in this group. The fourth group showed very weak enzymatic activity before heating, and was inactivated easily by heating. Asp.oryzae of the Asp. flavus group showed a very strong dextrinogenic amylase activity before heating. After the heat treatment, however, its enzymatic activity was diminished greatly.

• Preventive Nutrition and Food Science
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• 제14권1호
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• pp.21-28
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• 2009

In this study, we focused on natural water-soluble antioxidants from Tetraselmis suecica (T. suecica) and Chlorella ellipsoidea (C. ellipsoidea). They were prepared by enzymatic digestion using five carbohydrases (Viscozyme, Celluclast, AMG, Termamyl and Ultraflo) and five proteases (Protamex, Alcalase, Flavourzyme, Neutrase, and Kojizyme), and the potential antioxidant activity of each was assessed. Most enzymatic digests from T. suecica had a higher radical scavenging activity than those from C. ellipsoidea. Among the enzymatic digests, Kojizyme digest from T. suecica exhibited the highest effect on DPPH radical scavenging. Viscozyme (30.2%) and Neutrase (34.6%) digests from T. suecica exhibited higher hydroxyl radical scavenging activity. Kojizyme digest from T. suecica (81.5%) had strong alkyl radical scavenging activity. Neutrase (61.9%) and Kojizyme (61.5%) digest from T. suecica possessed the highest effects on hydrogen peroxide scavenging. Among the tested samples, Neutrase (TN) and Kojizyme (TK) digests from T. suecica showed the highest antioxidant activity (DPPH, alkyl radical, hydrogen peroxide). Therefore, TN and TK digests were selected for use in the further experiments. Those digests showed enhanced cell viability against $H_2O_2$-induced oxidative damage, and relatively good hydrogen peroxide scavenging activity in an African green monkey kidney (Vero) cell line. These results suggested that an enzymatic digestion will be an effective way for the production of a potential water-soluble antioxidant from a microalgae, T. suecica.

• Journal of Ginseng Research
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• 제44권6호
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• pp.784-789
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• 2020

Background: The separation of isomeric compounds from a mixture is a recurring problem in chemistry and phytochemistry research. The purification of pharmacologically active ginsenoside Rb₃ from ginseng extracts is limited by the co-existence of its isomer Rb₂. The aim of the present study was to develop an enzymatic elimination-combined purification method to obtain pure Rb₃ from a mixture of isomers. Methods: To isolate Rb₃ from the isomeric mixture, a simple enzymatic selective elimination method was used. A ginsenoside-transforming glycoside hydrolase (Bgp2) was employed to selectively hydrolyze Rb₂ into ginsenoside Rd. Ginsenoside Rb₃ was then efficiently separated from the mixture using a traditional chromatographic method. Results: Chromatographic purification of Rb₃ was achieved using this novel enzymatic elimination-combined method, with 58.6-times higher yield and 13.1% less time than those of the traditional chromatographic method, with a lower minimum column length for purification. The novelty of this study was the use of a recombinant glycosidase for the selective elimination of the isomer. The isolated ginsenoside Rb₃ can be used in further pharmaceutical studies. Conclusions: Herein, we demonstrated a novel enzymatic elimination-combined purification method for the chromatographic purification of ginsenoside Rb₃. This method can also be applied to purify other isomeric glycoconjugates in mixtures.

• 접착 및 계면
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• 제7권2호
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• pp.19-25
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• 2006

미생물 합성 고분자인 poly(hydroxylalkanoate)s (PHAs)의 초기효소분해는 표면침식의 메커니즘으로 진행하므로 이들의 분해거동은 표면특성을 개질로서 조절할 수 있다. 본 연구에서는 효소분해속도를 조절하기 위하여 플라즈마 기법을 PHAs 표면특성의 개질에 적용하였다. $CF_3H$와 $O_2$ 플라즈마를 사용하여 재료 표면에 각각 소수성 및 친수성을 부여하였다. 효소분해 실험은 pH 7.4의 0.1 M potassium phosphate 완충용액에서 Alcaligenes facalis T1에서 정제된 poly(hydroxybutyrate) 분해효소를 첨가하여 행하였다. $CF_3H$ 플라즈마 처리된 시편의 경우 표면 층의 불소화에 따른 소수성의 증가와 분해 효소에 대한 비활성으로 초기분해 속도가 상당히 지연됨을 관찰하였으나 $O_2$ 플라즈마 처리에 의한 표면 친수성은 분해속도의 촉진 등에 큰 영향을 미치지 않았다.

• Journal of the Korean Wood Science and Technology
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• 제48권5호
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• pp.651-665
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• 2020

Hydrolysis of biomass for the production of fermentable sugar can be improved by the addition of surfactants. In pulp and paper mills, lignin, which is a by-product of the pulping process, can be utilized as a fine chemical. In the hydrolysis process, lignin is one of the major inhibitors of the enzymatic breakdown cellulose into sugar monomer. Therefore, the conversion of lignin into a biosurfactant offers the opportunity to solve the waste problem and improve hydrolysis efficiency. In this study, lignin derivatives, a biosurfactant, was applied to enzymatic hydrolysis of various lignocellulosic biomass. This Biosurfactant can be prepared by reacting lignin with a hydrophilic polymer such as polyethylene glycol diglycidylethers (PEDGE). In this study, the effect of biosurfactants on the enzymatic hydrolysis of pretreated sweet sorghum bagasse (SSB), oil palm empty fruit bunch, and sugarcane trash with different lignin contents was investigated. The results show that lignin derivatives improve the enzymatic hydrolysis of the pretreated biomass with low lignin content, however, it has less influence on the enzymatic hydrolysis of other pretreated biomass with lignin content higher than 10% (w/w). The use of biosurfactant on SSB kraft pulp can increase the sugar yield from 45.57% to 81.49%.

• 한방비만학회지
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• 제21권1호
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• pp.1-9
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• 2021

Objectives: The enzymatic hydrolysis is one of the processing methods that improve its effectiveness on medicinal herbs. In this research, changes in ingredients and activity by enzymatic hydrolysis were studied. Methods: For this study, a carbohydrate hydrolase such as viscozyme, which converts glycosides to aglycone, was applied to induce constituent changes in Sophora japonica Linne, Houttuynia cordata Thunberg and Leonurus japonicus Houttuyn. Changes in antioxidant activity were measured using the 1,1-diphenyl-2-picrylhydrazl (DPPH) method, and changes in ingredients were analyzed by high performance liquid chromatography. Results: As a result of enzymatic hydrolysis, the content of quercetin was increased from 1.26 mg/g to 29.66 mg/g in Sophora japonica Linne, from 0 mg/g to 0.66 mg/g in Houttuynia cordata Thunberg and from 0.43 mg/g to 0.71 mg/g in Leonurus japonicus Houttuyn. As a result of the antioxidant experimentation, the IC₅₀ of Sophora japonica Linne decreased from 5 ug/ml (MeOH extract) and 9.1 ug/ml (EtOAc fraction) to 3.0 ug/ml, Houttuynia cordata Thunberg decreased from 15.6 ug/ml (MeOH extract) and 13.6 ug/ml (EtOAc fraction) to 11.2 ug/ml, and Leonurus japonicus Houttuyn decreased from 14.4 ug/ml (MeOH extract) and 12.6 ug/ml (EtOAc fraction) to 10.2 ug/ml. Conclusion: In conclusion, it was confirmed that glycoside rutin contained in the three medicinal herbs was changed to quercetin which is the aglycone, by the enzymatic hydrolysis using viscozyme. In terms of antioxidant activity, Sophora japonica Linne showed a significant antioxidant activity value that closes to the control group butylated hydroxyanisole. Houttuynia cordata Thunberg and Leonurus japonicus Houttuyn showed a minor increase in antioxidant activity.

• Applied Biological Chemistry
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• 제30권1호
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• pp.71-76
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• 1987

재래종 황색계자두 효소와 4종류의 polyphenol 화합물과 반응시켜 얻어진 효소적 갈변반응 생성물에 대하여 변이원성 및 변이원 억제작용에 관한 실험결과 B. subtilis H17과 M45 두 균주를 이용한 rec-assay에서 4종류의 갈변반응 생성물 모두 변이원성은 없었다. rec-assay에서 금속이온의 영향을 실험한 결과 pyrogallol의 갈변반응 생성물의 경우 $Fe^{3+},\;Mn^{2+},\;Zn^{2+},\;Ni^{2+}\;Al^{2+}$에서 약한 영향을 받았으며 hydroxyhydroquinone의 갈변반응 생성물에서는 $Cu^{2+},\;Pb^{2+}$, 그리고 catechol의 갈변반응 생성물에서는 $Mn^{2+}$ 공존하에서 약한 영향을 받았다. DNA절단실험 결과 갈변반응 생성물 자체에 의해서는 4종류의 시료 모두 DNA절단능력은 없었다. 금속이온의 영향에서는 $Fe^{2+}$의 경우 그 자체에 의해 절단되었으며 $Cu^{2+}$은 DNA 절단을 촉진하는 것으로 나타났다. S-9 mix를 첨가한 돌연변이 유발실험에서는 4종류의 갈변반응 생성물 모두 농도증가에도 변이원성은 없었으며 변이원 물질인 $benzo\;{\alpha}\;pyrene$에 대한 돌연변이원 억제반응에서는 4종류의 갈변반응 생성물 모두 농도증가에 따라 대조구에 비해 강한 억제작용을 나타냈다. 따라서 재래종 황색계 자두로부터 추출한 polyphenol oxidase와 4종류의 polyphenol 화합물과 반응시켜 얻어진 효소적 갈변반응 생성물의 들연변이원성 실험결과 갈변반응 생성물자체에 의한 돌연변이원성은 없었으며 금속이온의 영향도 받지 않는 것으로 나타났으나 강력한 발암물질인 $benzo\;{\alpha}\;pyrene$을 사용한 돌연변이 억제실험에서는 4종류의 갈변반응 생성물 모두 강한 돌연변이 억제작용이 있음을 알 수 있었다.