• 한국미생물·생명공학회지
• /
• 제21권3호
• /
• pp.276-280
• /
• 1993

Cell lytic enzyme, 5'-phosphodiesterase, and AMP-deaminase were used to produce yeast extract as a natural seasoning from beer yeast cells. Prior to the addition of cell lytic enzyme, heat treatment was performed to increase the cell wall degradation` the optimum condition of the cell lytic enzyme was 50C at pH 7.0. The production yields by the enzymatic method and conventional autolysis method were 42% and 35%, respectively. The total quantity of 5'-nucleotides, GMP and IMP, produced by enzymatic method was increased by 45% than that by the conventional method. Futhermore, the operation time of enzymatic method was only 6.5 hrs, significantly reduced from 24 hrs of the conventional method.

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

• Journal of the Korean Wood Science and Technology
• /
• 제17권3호
• /
• pp.45-51
• /
• 1989

A major problem in the enzymatic hydrolysis of lignocellulosic substrates is the very strong bonding of cellulase to lignin and even cellulose in the hydrolysis residues. This phenomenon inhibits recycle of the cellulase which is a major expense of the enzymatic hydrolysis process. In this paper, autohydrolyzed wood was delignified by two-stage with a 0.3% Na OH extraction and oxygen-alkali bleaching and was subjected to enzymatic hydrolysis with cellulase. Also, an improved almost quantitative recycle process of cellulase enzyme was discussed. In enzyme recovery by affinity method. the first recycling showed relatively high hydrolysis rate of 97.4%. Even at the third recycle. hydrolysis rate was 86.7 percents. In the case of cellulase recovery by ultrafiltration method, first 2 recycling treatments resulted very high hydrolysis rate(97.0-97.7%). Even the third recycling showed about 94.2%. Authoydrolysis of oak wood followed by 2-stage delignification with alkali and oxygen-alkali produced a substrate for enzymatic hydrolysis that allowed almost quantitative recycle of cellulase.

• Journal of the Korean Wood Science and Technology
• /
• 제18권4호
• /
• pp.18-25
• /
• 1990

As polysaccharides in lignocellulosic materials are encrusted with aromatic lignin molecules and have high crystallinity, these require pretreatment to improve their digestability by cellulolytic enzymes. Though a number of pretreatment methods have been proposed, the steam explosion process is evaluated as a promising method. This study was performed to investigate the effect of delignification treatment by alkali, methanol and the others on the enzymatic hydrolysis. Delignification treatment resulted in great increase rate in enzymatic hydrolysis. Concerning to the effect of delignication reagents on the enzymatic hydrolysis, methanol treatment was more effective than alkali in the case of oak wood. In pine wood, the delignification did not showed any significant enhancement of hydrolysis rate. Complete delignification by Alkali-Oxygen. Alkali treatment showed high saccharification rate of 99.5%.

• 한국식품과학회지
• /
• 제29권2호
• /
• pp.383-386
• /
• 1997

아밀로오스 함량이 다른 옥수수 전분을 고압 가열-냉각 사이클을 4회까지 반복한 후, 효소 중량법과 ${\alpha}-amylase$ 처리로 효소저항전분을 분리하여 그 수율을 비교하였다. 분리방법에 상관없이 아밀로오스 함량이 높을수록 효소저항전분의 수율이 증가하였고, 가열-냉각 횟수를 증가시키면 효소저항전분의 수율도 증가하였다. 효소저항전분의 분리는 효소 중량법이 ${\alpha}-amylase$ 처리로 효소저항전분을 분리할 때보다 순도가 높았다.

• Journal of the Korean Wood Science and Technology
• /
• 제19권1호
• /
• pp.14-21
• /
• 1991

Steam-exploded woods were delignified by two-stage with a 0.3% NaOH extraction and oxygen-alkali bleaching and were subjected to the enzymatic hydrolysis with cellulase enzyme. Also, an improved almost quantitative recycle process of cellulase enzyme was discussed. In enzyme recovery by affinity method, The first recycling showed relatively high hydrolysis rate of 96.4%. Even at the third recycle, hydrolysis rate was 87.0 percents. In the case of cellulase recovery by ultrafiltration method, first 2 recycling treatments resulted in very high hydrolysis rates, 96.8% and 95.0%, respectively. Even the third recycling showed about 93.6%. Steam-explosion treatment of oak wood followed by 2-stage delignification with alkali and oxygen-alkali produced a excellant substrate for the enzymatic hydrolysis that allowed almost quantitative recycle of cellulase.

• KSBB Journal
• /
• 제16권5호
• /
• pp.446-451
• /
• 2001

신문지와 같은 폐지지 적합한 전처리 방법을 조사하였다. 조사방법은 전처리 후 기질의 효소 가수분해에 영향을 미칠수 있는 인자, 즉 회분의 양, 기질 크기의 잉크의 유무에 따른 효소 당화율을 측정하였다. 이 세 인자 중 잉크가 효소당화율에 미치는 영향이 가장 커서 잉크를 제거하는 방향으로 전처리 방법을 고안하였다. 먼저 섬유성 기질에서 성능이 입증된 percolation반응기에 의한 전처리 방법을 사용하였다. 그러나 17$0^{\circ}C$에서 전처리된 기질은 잉크가 거의 제거되지 않앗고 효소 당화율도 전처리하지 않은 기질보다 더 낮았다. 그래서 10$0^{\circ}C$이하의 낮은 온도에서 회분식 반응기를 사용하는 방법을 연구했는데 암모니아에 과산화수소를 첨가하여 진탕교반시키는 방법이 가장 효과적이었다. 이 방법의 효소 당화율은 전처리하지 않은 기질보다 약 20% 증가한 85%이어서 신문지와 같은 폐지의 전처리에 아주 효과적이었음을 알수 있었다. 이와 같은 높은 당화율은 암모니아에 첨가한 과산화수소가 잉크제거와 기질을 팽윤시키는 작용을 하기 때문이라고 생각된다.

• 상하수도학회지
• /
• 제12권2호
• /
• pp.115-126
• /
• 1998

In use of anaerobic bioconversion shellfish wastes present special problems, since the chitinous structures in the shell faction degrade very slowly in an anaerobic environment. Enzymatic pretreatment method was evaluated for improving the anaerobic bioconversion potential of blue crab processing wastes. An enzymatic pretreatment using chitinase enhanced the ultimate methane yield and biodergradation rate constant for total crab solid wastes by 15% and 19% respectively, above those of the untreated wastes. When the enzymatic pretreatment applied to the shell fraction alone, it resulted in increase of 34% in the ultimate methane yield and 38% in the reaction rate. The results indicate that anaerobic bioconversion of these wastes is technically feasible and enzymatic pretreatment will improve the efficiency of the process.

• 한국수정란이식학회지
• /
• 제26권4호
• /
• pp.223-227
• /
• 2011

The objective of this study was to compare of different isolation method of mouse preantral follicles, and to examine in vitro development of mouse preantral follicles isolated by different method. Preantral follicles were mechanically or enzymatically extracted from mouse ovaries. Mechanical isolation method used fine gauge needles and enzymatic method of isolating follicles used collagenase. The recovered preantral follicles were cultured for 10 days in alpha-minimal essential medium (${\alpha}$-MEM) + 5% FBS + Insulin-Transferrin-Selenium (ITS) + 100 mIU/ml FSH. The collected primary follicles by enzymatic treatment were higher than mechanical method. Others stage preantral follicle by mechanical isolation were higher than enzymatic method. After 10 days of culture, no statistical differences were shown in survival rates of preantral follicle among the 2 culture groups. The metaphase II rates of the oocytes were significantly higher (p<0.05) in mechanical method (17.8%) than in enzymatic method (5.1%). These results suggest that the isolation method of choice depends on the target stage preantral follicles and mechanical isolation is an optimal method of preantral folliclesin a culture of mouse preantral follicle.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
• /
• pp.194-197
• /
• 2000

The color of textile-wastewater hindered spectrometric measurements of $H_2O_2$ and enzyme activity during enzymatic decoloring. By using ABTS, we developed a new method for measuring peroxidase activity and $H_2O_2$ concentration. The ratio of enzyme and $H_2O_2$ was optimized as 1:150 by investigating the effects of $H_2O_2$ on enzymatic decoloring. Pulse feeding of $H_2O_2$, upon depletion, significantly increased the decoloring of Congo Red.