• 한국균학회지
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• 제17권4호
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• pp.169-176
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• 1989

1. 느타리버섯 중의 미토콘드리아는 설탕농도 44% 층에서 분리 정제되었다. 2. 파장 변화에 따른 미토콘드리아성 ATPase의 활성도는 580nm의 빛이 조사될 때 가장 크게 증가되었다. 3. 최적 파장 580nm의 빛 조사시간 변화에 따른 활성도는 10초 동안 조사하였을 때 가장 크게 증가하였다. 4. 최적 빛 조사 조건에서 이 효소의 최적 pH는 7.4, 최적 온도는 $60^{\circ}C$였다. 5. 최적 광 조건에서 얻은 이 효소는 $Fe^{3+}$, $Fe^{2+}$, $Ca^{2+}$, $Mg^{2+}$ 및 $K^{+}$ 이온에 의하여 활성화 되었으나 $Na^{+}$ 이온에 의해서는 억제되었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제3권2호
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• pp.87-90
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• 1998

Hemolymph is oxidized and darkens visibly during the collection from silkworm due to the activity of tyrosinase in it. Toxic quinones are produced by the oxidation and consequently inhibit the cell growth. Heat treatment can be used to prevent the oxidation ; however, the oxidation may occur during the collection of hemolymph before it is heat-treated. It makes the hemolymph collection difficult especially on a large-scale preparation. Hemolymphs collected from 257 different strains of silkworms were examined to select the slowly oxidized hemolymphs. Hemolymphs collected from mutant strains such as Lemone, TBO, Cre, Y4, and wEb showed relatively slow color changes. Oxidation rates of the hemolymphs were measured by the absorbance change using a spectrophotometer. The hemolymph of wEb showed the slowest oxidation. The absorbance of this mutant hemolymph reached the saturation value at 20$^{\circ}C$ in 450 min, whereas the total oxidation time of the wild-type (Baekokjam) hemolymph at the same temperature was 120 min. We tested if this mutant hemolymph is useful as a medium supplement for insect cell culture. Cell growth rate and final cell concentration in the medium supplemented with the wEb hemolymph were almost same as those in the medium supplemented with the wild-type hemolymph. Hemolymph is collected on a small scale by clipping the abdominal leg; however, this method is not appropriate fro large scale preparation. Centrifugation after chopping the silkworm hemolymph by a blending mixer is a more appropriate procedure for large scale collection. Slowly oxidized wEb hemolymph resulted in higher cell concentration than the wild-type hemolymph when hemolymph was collected by the large scale preparation method.

• 한국식품과학회지
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• 제18권3호
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• pp.197-203
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• 1986

부분도정한 보리를 미생물효소(Asp. niger 및 oryzae)에 의한 분해반응 및 미세 고형분의 용출, 여과, 침강 또는 원심분리, 건조 등의 과정을 거쳐 제분할 때, 보리가루 획분$(73{\sim}76%)$, 맥강, 배아, 종구등의 잔유물 획분(3.6% 내외) 그리고 가용성물질 획분 등으로 분리하여 얻을 수 있었다. 이 때 가장 좋은 효소반응 조건은 온도 $45^{\circ}C$, 보리와 물의 비율 1 : 1.5(w/v)였고, ${\alpha}-a-mylase$역가 보다는 glucanase 와 Protease의 역가가 높은 효소를 사용할 때 더 좋은 효과를 보였다. 그리고 얻어진 세가지 종류 획분의 성분 조성은 단백질, 지방, 섬유소 등에서 각각 현저한 차이를 보여, 각 획분의 특성별 구분 이용이 가능하였다.

• International Journal of Industrial Entomology and Biomaterials
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• 제35권2호
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• pp.77-82
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• 2017

We studied on improvement method of rutin content using mulberry leaf powder. Mulberry leaves were collected and then hot-air dried and powdered for experiment. As a result, we have developed a pre-treatment method that extracts mulberry leaf powder with water or fermented alcohol with reflux extractor and then increases the rutin content by improving the process. Citric acid (0.1 ~ 1%) and 1000 ml fermented alcohol (50 ~ 95%) or water (10 ~ 50 times) was extracted with 100 g of mulberry leaf powder using a reflux extraction device ($80{\sim}90^{\circ}C$, 1 hour, twice). The extracts were collected, filtered and concentrated. For the recrystallization, the concentrate was dissolved by adding distilled water and allowed to stand at a low temperature. Then, the supernatant was discarded by centrifugation, and only the residue was lyophilized to prepare a final powder. As a result, regardless of the concentration of citric acid added, the content of rutin was higher in 90% fermented alcohol extract. Whereas, in the case of extracting with water, citric acid 0.5% was added to water 25 times as much as the weight of mulberry leaf powder, and 2274.4 (mg / 100g) of rutin content was highest in the case of refluxing twice at $80^{\circ}C$ for 1 hour. The powder with increased rutin content is expected to be applicable to various foods as a food additive. In addition, it can contribute to the improvement of the farm income by promoting consumption of mulberry leaf while satisfying the consumers' desire for functional food intake.

• 한국재료학회지
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• 제33권7호
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• pp.265-272
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• 2023

In this study, the synthesis of nitrobenzene was carried out using sulfated silica catalyst. The study delved into H₂SO₄/SiO₂ as a solid acid catalyst and the effect of its weight variation, as well as the use of a microwave batch reactor in the synthesis of nitrobenzene. SiO₂ was prepared using the sol-gel method from TEOS precursor. The formed gel was then refluxed with methanol and calcined at a temperature of 600 ℃. SiO₂ with a 200-mesh size was impregnated with 98 % H₂SO₄ by mixing for 1 h. The resulting 33 % (w/w) H₂SO₄/SiO₂ catalyst was separated by centrifugation, dried, and calcined at 600 ℃. The catalyst was then used as a solid acid catalyst in the synthesis of nitrobenzene. The weights of catalyst used were 0.5; 1; and 1.5 grams. The synthesis of nitrobenzene was carried out with a 1:3 ratio of benzene to nitric acid in a microwave batch reactor at 60 ℃ for 5 h. The resulting nitrobenzene liquid was analyzed using GC-MS to determine the selectivity of the catalyst. Likewise, the use of a microwave batch reactor was found to be appropriate and successful for the synthesis of nitrobenzene. The thermal energy produced by the microwave batch reactor was efficient enough to be used for the nitration reaction. Reactivity and selectivity tests demonstrated that 1 g of H₂SO₄/SiO₂ could generate an average benzene conversion of 40.33 %.

• 임산에너지
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• 제17권1호
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• pp.56-70
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• 1998

This study was carried out to investigate the structural characteristics of kraft lignin and the wood degrading characteristics, the productivity of ligninolytic enzymes and the enzymatic degradation of kraft lignin by white-rot fungi. To purify kraft lignin, precipitation of kraft pulping black liquors of pitch pine meal was done by titration with lN $H_{2}SO_{4}$ reaching to pH 2, and isolation of the precipitates done by centrifugation. The isolated precipitates from pitch pine were redissloved in lN NaOH, reprecipitated by titration with lN $H_{2}SO_{4}$, washed with deionized water, and kept ofr analysis after freeze drying. Fractionation of the precipitates in solution by successive extraction with $CH_{2}Cl_{2}$ and MeOH, and the fractionates were named SwKL, SwKL I, SwKL II, and SwKL III for pitch pine kraft lignin. The more molecular weights of kraft lignin increased, the less phenolic hydroxyl groups and the more aliphatic hydroxyl groups. Because as the molecular weights increased, the ratio of etherified guaiayl/syringyl(G/S ratio) and the percentage were increased. The spectra obtained by 13C NMR and FTIR assigned by comparing the chemical shifts of various signals with shifts of signals from autherized ones reported. The optimal growth temperature and pH of white-rot fungi in medium were $28^{\circ}C$ and 4.5-5.0, respectively. Especially, in temperature and pH range, and mycelial growth, the best white-rot fungus selected was Phanerochaete chrysosporium for biodegradation. For the degradation pathways, the ligninolytic fungus jcultivated with stationary culture using medium of 1% kraft lignin as a substrate for 3 weeks at $28^{\circ}C$. The weight loss of pitch pine kraft lignin was 15.8%. The degraded products extracted successively methoanol, 90% dioxane and diethyl ether. The ether solubles were analyzed by HPLC. Kraft lignin degradation was initiated in $\beta$-O-4 bonds of lignin by the laccase from Phanerochaete chrysosporium and the degraded compounds were produced from the cleavage of $C\alpha$-$C\beta$ linkages at the side chains by oxidation process. After $C\alpha$-$C\beta$ cleavage, $C\alpha$-Carbon was oxidized and changed into aldehyde and acidic compounds such as syringic acid, syringic aldehyde and vanilline. And the other compound as quinonemethide, coumarin, was analyzed. The structural characteristics of kraft lignin were composed of guaiacyl group substituted functional OHs, methoxyl, and carbonyl at C-3, -4, and -5 and these groups were combinated with $\alpha$ aryl ether, $\beta$ aryl ether and biphenyl. Kraft lignin degradation pathways by Phanerochaete chrysosporium were initially accomplished cleavage of $C\alpha$-$C\beta$ linkages and $C\alpha$ oxidation at the propyl side chains and finally cleavage of aromatic ring and oxidation of OHs.

• 한국가축번식학회지
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• 제7권2호
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• pp.57-71
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• 1983

1. Diluted chicken semen can be preserved at 2 to 5$^{\circ}C$ for 24 to 48 hr with resultant fertility of greater than 90% of that of fresh semen. Turkey semen can be preserved at 10 to 15$^{\circ}C$ for 6 to 24 hr and provide economical fertility. 2. Frozen chicken semen has given variable results; a 21 to 93% fertility ranges as compared to 92 to 94% expected with fresh semen. Highest fertility levels obtained with frozen turkey semen intravaginally inseminated have been 61 and 63% using DMSO and glycerol, respectively, as cryoprotectants. 3. The use of glycerol as a cryoprotectant reauires that its concentration in semen be reduced to less than 2% either by dialysis or centrifugation after thawing and before intravaginal insemination if optimal fertility is to be obtained. 4. The temperature at which cryoprotectants are added to semen and the time allowed for equilibration are important for subsequent fertility pre- and post-freezing. 5. The type of container used for packaging the semen, freeze or cooling rates, thaw rates and level of cryoprotectant all interact in affecting cell survival. 6. Plastic freeze straws as a packaging device for semen offers the following advantages: easy to handle, require minimal storage space, offer a wide range of freeze and thaw rates, and insemination can be made directly from them upon thawing. 7. Controlled slow cooling rates of 1 to 8$^{\circ}C$/min have thus far provided the best results for cooling chicken semen throught the transition phase change (liquid to solid) or critical temperature range of ＋5 to -20 or -35$^{\circ}C$. 8. Highest fertilities have been achieved with frozen chicken semen where a slow thaw rate (2。 to 5$^{\circ}C$) has been used regardless of the freeze rate. 9. To maintain a constant high level of fertility throughout a breeding season with frozen semen, a higher absolute number of spermatozoa must be inseminated (2 to 3 times as many) as compared to fresh semen since a, pp.oximately 50% are destroyed during processing and freezing. 10. The quality of semen may vary with season and age of the male. Such changes in sperm quality could be accentuated by storage effects. Thus, the correct number of spermatozoa may very well vary during the course of a breeding period. 11. As to time of insemination, it is best to avoid inseminating chicken hens within 1-2 hr after or 3-5 hr before oviposition; and turkey hens during or 7-10 hr before oviposition. 12. The physiological receptiveness of the oviduct at the time of insemination is a very important biological factor influencing fertility levels throughout the breeding season.

• 생물환경조절학회지
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• 제4권2호
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• pp.136-143
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• 1995

Canola(Brassica napus) 엽에서 추출한 미세막으로부터 PEG-dextran 2상분획법을 이용하여 세포막과 세포내막을 분리하였다. U$_2$ 상에 있는 원형질막의 $K^{+}$-ATPase의 특이활성도가 미세막에 비하여 $25^{\circ}C$에서 자란 canola는 6.6배, 1$0^{\circ}C$에서 4.6배 각각 증가되었다. 원형질막(U$_2$)은 미세막이나 세포내막(L$_2$) 보다 cytochrome-c-oxidase 활성이 적게 나타난 반면, 세포내막에서는 $K^{+}$-ATPase의 특이활성도가 가장 적게 나타났다. 1$0^{\circ}C$에서 생장한 canola의 18:3/18:2 률은 $25^{\circ}C$보다 29.2% 더 높게 나타났다. 원형질막의 2중결합지수는 1$0^{\circ}C$에서 생장한 canola가 $25^{\circ}C$에서 생장한 것보다 8.9% 더 증가되었으며 세포내막에서도 같은 경향으로써 1$0^{\circ}C$에서 19.7% 더 증가되는 현상을 보였다. 또한 엽록소 함량은 1$0^{\circ}C$에서 생장한 것이 $25^{\circ}C$에 비하여 17.3% 낮았다. Canola가 저온에서 생장시 주로 $C_{18}$ 지방산들이 변화되어, 세포막 내에 불포화 지방산이 많았으며, 그 중에서도 리롤렌산(18:3)이 크게 변화되는 현상을 보였다. 이러한 변화는 생리적으로 canola의 세포막이 저온에 살아가기 위한 하나의 수단으로 추정된다.

• 대한물리의학회지
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• 제9권1호
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• pp.45-53
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• 2014

PURPOSE: In this study, we tried to find out what kind of exercise was more effective in sleep disorder by comparing melatonin in blood after applying low intensity with high intensity exercise to sleep disordered rats induced by experiment. METHODS: We used male Sprague-Dawley rats which were 8weeks old and weighted 300g. They were supplied with water and food without any restriction. We kept the room temperature at $25^{\circ}C$ and controld the length of day and night in 12 hours blocks, respectively. We divided the rats 60 into 2 groups. To one group we applied low intensity exercise, and to the other we applied high intensity exercise for 15minutes per day over a period of 4 weeks. We extracted the blood from abdominal aorta before, after exercise, moved into EDTA tube, performed centrifugation. We decanted the serum $200{\mu}l$ from the blood into microcentrifuge tube by samples and moved into polypropylene culture tubes with micro pipette. We split enzyme solution $50{\mu}l$ into the tubes with melatonin direct kits and make them react at $37^{\circ}C$ for 2 hours. We split assay buffer $50{\mu}l$ into each tube and mixed melatonin tracer $50{\mu}l$ and melatonin antiserum $50{\mu}l$, respectively. After we made them react in room temperature, we decanted the superficial layer with a centrifuge and measured the activity for 1 minute by competitive method with ${\gamma}$-counter equipment. We draw a standard curve through logit-log graph with CPM(counts per minute) and counted the melatonin by B/B0. We conducted independent t-test to examine the homogeneous of melatonin value of before low-intensity and high-intensity exercise. We performed paired t-test to compare before and after low-intensity and high-intensity exercise, respectively. We carried out independent t-test to compare melatonin value after low-intensity and high-intensity exercise. Significance level was .05. RESULTS: The results were as follows; firstly melatonin was more increased in the group who was exposed to high intensity exercise when we compared before to after high and low intensity exercise, respectively. Secondly, high intensity exercise was more effective than low intensity exercise when we compared the two. CONCLUSION: In conclusion, secretion of melatonin which is the material of sleep improvement could be promoted by high intensity exercise. Low intensity exercise acted as a stress rather than improving sleep and had a negative effect on the secretion of melatonin because the melatonin was affected by stress.

• 한국미생물·생명공학회지
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• 제46권3호
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• pp.234-243
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• 2018

남극해에는 산업적으로 유용한 신규 효소촉매를 생산하는 미생물들이 들어 있다. 우리는 로스해(Ross Sea)로부터 분리한 여러 저온성 박테리아를 조사하였으며, 그 중에서 지방분해 능력이 뛰어난 Croceibacter atlanticus (No. 40-F12)를 찾았다. Shotgun 클로닝 방법으로 리파아제 유전자(lipCA)를 찾았으며 Escherichia coli 균에서 LipCA 효소를 발현하였다. Spain Arreo metagenome alpha/beta hydrolase를 기준으로 LipCA 상동구조모델을 만들어서 분석한 결과, ${\alpha}/{\beta}$ hydrolase fold, Gly-X-Ser-X-Gly motif, 그리고 lid 구조를 갖고 있기 때문에 전형적인 리파아제 효소임이 밝혀졌다. Ammonium sulfate 침전법과 겔여과 크로마토그래피를 통해서 세포추출액으로부터 LipCA 효소를 순수하게 분리한 후, 최적 온도, pH, 안정성, 기질특이성, 유기용매 안정성 등의 효소특성을 규명하였다. LipCA를 cross-linked enzyme aggregate (CLEA) 방법으로 고정화하고 효소특성을 조사, 비교하였다. 고정화를 통해 온도, pH, 유기용매에 대한 안정성이 증가하였고 기질특이성의 변화는 관찰되지 않았다. $LipCA^{CLEA}$는 원심분리 방법으로 쉽게 회수되었고 4번의 재사용 후에 40% 이상의 활성이 잔재하였다. 이 논문은 C. atlanticus 리파아제의 발현, 특성규명, Cross-linked Enzyme Aggregated 고정화를 바탕으로 안정성을 높여 산업적 활용 가능성을 제시한 최초의 보고이다.