• Preventive Nutrition and Food Science
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• 제13권3호
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• pp.166-175
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• 2008

In this study, we focused on natural water-soluble antioxidants from the Jeju benthic diatoms, Achnanthes longipes, Navicula sp. and Amphora coffeaeformis. They were prepared by enzymatic digestion using five carbohydrases (Viscozyme, Celluclast, AMG, Termamyl and Ultraflo) and five proteases (Protamex, Kojizyme, Neutrase, Flavourzyme and Alcalase) and their potential antioxidant activity was assessed. Among the enzymatic digests, Neutrase digest from A. coffeaeformis exhibited the highest effect in DPPH radical scavenging. Flavourzyme (48.7%), Viscozyme (47.4%) and Celluclast (45.7%) digests from Navicula sp. exhibited higher $O^{{\cdot}-}_2$ radical scavenging activity. Viscozyme digest from A. coffeaeformis (45.9%) possessed the highest effects in hydroxyl radical scavenging. Termamyl (89.3%) and Protamex (88.8%) digests from A. coffeaeformis had strong metal chelating activity. Lipid peroxidation was significantly inhibited in Termamyl and Kojizyme digests from A. longipes, AMG and Termamyl digests from Navicula sp. and Kojizyme digest from A. coffeaeformisi. These data suggest that enzymatic digests of the Jeju benthic diatoms might be valuable sources of antioxidant which can be applied in food and pharmaceutical industry.

• Mass Spectrometry Letters
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• 제7권1호
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• pp.1-11
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• 2016

Various efforts have been developed to improve sample preparation steps, which strongly depend on hands-on processes for accurate and sensitive quantitative proteome analysis. In this study, we carried out heating the sample prior to trypsin digestion using an instrument to improve the tryptic digestion process. The heat shock generated by the system efficiently denatured proteins in the sample and increased the reproducibility in quantitative proteomics based on peptide abundance measurements. To demonstrate the effectiveness of the protocol, three cell lines (A human lung cancer cell line (A549), a human embryonic kidney cell line (HEK293T), and a human colorectal cancer cell line (HCT-116)) were selected and the effect of heat shock was compared to that of normal tryptic digestion processes. The tryptic digests were desalted and analysed by LC-MS/MS, the results showed 57 and 36% increase in the number of identified unique peptides and proteins, respectively, than conventional digestion. Heat shock treated samples showed higher numbers of shorter peptides and peptides with low inter-sample variation among triplicate runs. Quantitative LC-MS/MS analysis of heat shock treated sample yielded peptides with smaller relative error percentage for the triplicate run when the peak areas were compared. Exposure of heat-shock to proteomic samples prior to proteolysis in conventional digestion process can increase the digestion efficiency of trypsin resulting in production of increased number of peptides eventually leading to higher proteome coverage.

• 한국식품영양과학회지
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• 제1권1호
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• pp.51-62
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• 1972

In Korea, fermented fish has been playing an important role as a preserved and flavor rich food. It is said that the digestion of fish protein is due to both action of intrinsic (autolytic enzymes) and bacterial enzymes in fish. The mass production of fermented fish has been impeded since traditional method of fermentation requires a long duration for a complete digestion. A high concentration of salt and unsanitary condition are also considered disadvantages of the old method. To improve the quality of the product and to develop mechanized process of fermentation, fermentors which have such control device as temperature, pH and agitation control system have been urgently needed. In this study, a model design of a fermentor is studied. The calculation was based on the optimum conditions for enzymatic hydrolysis of fish protein which involve temperature, pH, viscosity and other factors.

• 한국식품과학회지
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• 제31권2호
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• pp.475-481
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• 1999

핵산 함량이 높은 변이주 Saccharomyces cerevisiae B24를 산업적으로 활용하기 위해 배양 후 자기소화 혹은 효소 분해법으로 효모 추출물을 제조하였다. 배양액의 균체 농도를 10% (w/w)로 하고 pH 5.0, $50^{\circ}C$에서 서서히 교반하면서 48시간 자기소화시켰을 때 세포 내용물이 효모 추출물로 이전되는 수율은 65% 정도였으나 리보핵산은 정미력이 없는 다른 성분으로 분해되어 정미성 핵산성분인 5'-IMP나 5'-GMP가 거의 검출되지 않았다. 반면 $90^{\circ}C$ 이상의 온도로 B24 배양액 1 L를 열처리하여 핵산 분해 효소를 불활성화시키고 세포벽을 변성시킨 다음 ${\beta}-1,3-glucanase$, phosphodiesterase, adenylic deaminase, protease 등을 순차적으로 작용시켜 정미성 5'-IMP와 5'-GMP가 총 3.2% 함유된 효모 추출물(고형분 함량 70%) 84 g을 얻을 수 있었고 이 때 추출물 수득율은 고형분 기준으로 85% 이었다. 반면 모균주인 S. cerevisiae ATCC 7754를 효소적으로 분해할 때 정미성 5'-IMP와 5'-GMP가 총 2.2% 함유된 효모 추출물(고형분 함량 70%)을 77 g밖에 얻지 못하였다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.167-170
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• 2000

B. Stearothermophilus 단백질 분해 효소는 2가 금속 이온인 $Ca^{2+}$에 의하여 내열성이 향상되며 $75^{\circ}C$에서 최대 역가를 나타내었다. 2mM $Ca^{2+}$를 첨가하여 B. Stearothermophilus를 이용한 호열 ${\cdot}$ 호기성 소화공정 운전할 경우 각각 최대량 대비 51%와 27%의 DOC 및 세포외단백질의 분해가 이루어지는 것을 확인하였다.

• International journal of advanced smart convergence
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• 제5권2호
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• pp.18-23
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• 2016

Cell walls of microalgae consist of a polysaccharide and glycoprotein matrix providing the cells with a formidable defense against its environment. Anaerobic digestion (AD) of microalgae is primarily inhibited by the chemical composition of their cell walls containing biopolymers able to resist bacterial degradation. Adoption of pre-treatments such as thermal, thermal hydrolysis, ultrasound and enzymatic hydrolysis have the potential to remove these inhibitory compounds and enhance biogas yields by degrading the cell wall, and releasing the intracellular algogenic organic matter (AOM). This paper preproposal stage investigated the effect of different pre-treatments on microalgae cell wall, and their impact on the quantity of soluble biomass released in the media and thus on the digestion process yields. This Paper present optimum approach to degradation of the cell wall by ultra-sonication with practical design specification parameter for ultrasound based pretreatment system. As a result of this paper presents, a microalgae system in a wastewater treatment flowsheet for residual nutrient uptake can be justified by processing the waste biomass for energy recovery. As a conclusion on this result, Low energy harvesting technologies and pre-treatment of the algal biomass are required to improve the overall energy balance of this integrated system.

• 한국양식학회지
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• 제9권4호
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• pp.453-459
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• 1996

Cellulase was purified from marine rotifer, Brachionus plicatilis, to homogeneity by using chromatographic methods. Purified enzyme is an endo-${\beta}$-1,4 glucanase and shows a strong hydrolytic activity against carboxymethyl (CM) -cellulose. The physicochemical parameters of enzyme activity were determined. The molecular weight of the purified protein was approximately 62 kDa as determined by SDS-polyacrylamide gel electrophoresis. The enzymatic capability to digest cellulose of Chlorella cell wall was compared with that of other well known cellulases from Thermomonospora fusca. Experiments involving Chlorella digestion indicated that CM-cellulase from marine rotifer, Brachionus plicatilis, could digest Chlorella very efficiently while cellulase purified from Thermomonospora fusca did not. From the result here, we propose that the cellulolytic system from marine rotifer is responsible for the hydrolysis of cellulosic wall of Chlorella, probing that rotifer digests Chlorella as a major live food.

• 한국식품과학회지
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• 제10권4호
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• pp.394-397
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• 1978

한우(韓牛)의 round muscle에 papain으로 일차(一次) 분해(分解)시킨 후 pepsin에 의한 in vitro소화율(消化率)과 소화과정중(消化過程中) 생성(生成)되는 amino 태(態)-N의 경분적(經分的)인 변화(變化)를 실험(實驗)한 결과(結果)는 다음과 같다. 1. 효소처리구(酵素處理區)가 대조구(對照區)에 비(比)하여 소화율(消化率)도 높았으며 소화시간(消化時間)도 단축되었다. 2. 효소처리구(酵素處理區)는 소화과정중(消化過程中) $6{\sim}10$분간(分間)사이에 소화율(消化率)이 현저하게 증가(增加)하였다. 3. amino태(態)-N는 소화율(消化率)과 소화시간(消化時間)에 거의 비슷하게 증가(增加)하였다. 4. 대조구(對照區)에 비(比)하여 효소처리구(酵素處理區)가 amino태(態)-N 생성량(生成量)이 현저하게 높았으며$2{\sim}8$시간(時間)사이에서 그 증가율(增加率)이 가장 높았다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권3호
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• pp.225-229
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• 2005

To investigate impediments to plasmid transformation in Brevibacterium flavum BF4 and B. lactofermentum BL1, cell surface barriers were determined by measuring growth inhibition whilst enzymatic barriers were determined by comparing DNA methylation properties. B. lactofermentum was more sensitive to growth inhibition by glycine than B. flavum. Release of cellular proteins during sonication was more rapid for B. lactofermentum than for B. flavum. Plasmid DNA (pCSL 17) isolated from B. flavum transformed recipient $McrBC^+$ strains of Escherichia coli with lower efficiency than $McrBC^-$. McrBC digestion of this DNA confirmed that B. flavum contain methylated cytidines in the target sequence of McrBc sequences but B. lactofermentum contained a different methylation pattern. DNA derived from the B. lactofermentum transformed recipient $EcoKR^+$ strains of E. coli with lower efficiency than $EcoKR^-$, indicating the presence of methylated adenosines in the target sequence of EcoK sequences. The present data describe the differences in the physical and enzymatic barriers between two species of corynebacteria and also provide some insight into the successful foreign gene expression in corynebacteria.

• Preventive Nutrition and Food Science
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• 제20권3호
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• pp.183-189
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• 2015

In the present study, an optimum protease was selected to hydrolyze the egg white liquid protein for the antioxidant peptides. Alcalase treatment yielded the highest amount of ${\alpha}$-amino groups (15.27 mg/mL), while the control (no enzymatic hydrolysis) showed the lowest amount of ${\alpha}$-amino groups (1.53 mg/mL). Alcalase also gave the highest degree of hydrolysis (DH) value (43.2%) and was more efficient for egg white liquid hydrolysis than the other enzymes. The Alcalase hydrolysate had the highest radical-scavenging activity (82.5%) at a concentration of 5.0 mg/mL. The conditions for enzymatic hydrolysis of egg white liquid with Alcalase were selected as substrate : water ratio of 2:1. Five percent Alacalse treatment did not show significant (P>0.05) increases of DH and ${\alpha}$-amino nitrogen content after 24 hhydrolysis. Thirty two hour-hydrolysis with 5% Alcalase is sufficient to make antioxidative egg white liquid hydrolysate from egg white liquid. DPPH and ABTS radical-scavenging activities were significantly (P<0.05) higher after enzymatic digestion. These results suggest that active peptides released from egg-white protein are effective radical-scavengers. Thus, this approach may be useful for the preparation of potent antioxidant products.