• 한국수산과학회지
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• 제44권4호
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• pp.325-331
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• 2011

Nonylphenol (NP), which is well known as an endocrine disrupter, has been detected widely in untreated sewage or waste water streams. Given the necessity of discovering an eco-friendly method of degrading this toxic organic compound, this study was conducted to isolate NP-degrading microorganisms from the aqueous environment. NP-degrading microbes were isolated through NP-containing enrichment culture. Finally, a microbial consortium, SW-3, capable of degrading NP with high efficiency, was selected from the mixture sample. The microbial consortium SW-3 was able to degrade over 99% of 100 ppm NP in the culture medium for 40 days at $25^{\circ}C$. The microbial consortium SW-3 seemed to utilize NP as a carbon source, since NP was the sole carbon source in the culture medium. In order to isolate the NP-degrading bacterium, we further conducted single colony isolation using the microbial consortium SW-3. Four strains isolated from SW-3 exhibited lower NP-degradation efficiency than that of SW-3, suggesting that NP was degraded by the co-metabolism of the microbial consortium. We suggest that the microbial consortium obtained in this study would be useful in developing an eco-friendly bioremediation technology for NP degradation.

• Journal of Microbiology and Biotechnology
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• 제24권5호
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• pp.675-682
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• 2014

Approximately 50% of people in the world experience abdominal flatulence after the intake of foods containing galactosides such as lactose or soybean oligosaccharides. The galactoside hydrolyzing enzymes of ${\alpha}$- and ${\beta}$-galactosidases have been shown to reduce the levels of galactosides in both the food matrix and the human gastrointestinal tract. This study aimed to optimize the production of ${\alpha}$- and ${\beta}$-galactosidases of Bifidobacterium longum subsp. longum RD47 with a basal medium containing whey and corn steep liquor. The activities of both enzymes were determined after culturing at $37^{\circ}C$ at pH 6.0 for 30 h. The optimal production of ${\alpha}$- and ${\beta}$-galactosidases was obtained with soybean oligosaccharides as a carbon source and proteose peptone no. 3 as a nitrogen source. The optimum pH for both ${\alpha}$- and ${\beta}$-galactosidases was 6.0. The optimum temperatures were $35^{\circ}C$ for ${\alpha}$-galactosidase and $37^{\circ}C$ for ${\beta}$-galactosidase. They showed temperature stability up to $37^{\circ}C$. At a 1 mM concentration of metal ions, $CuSO_4$ inhibited the activities of ${\alpha}$- and ${\beta}$-galactosidases by 35% and 50%, respectively. On the basis of the results obtained in this study, B. longum RD47 may be used for the production of ${\alpha}$- and ${\beta}$-galactosidases, which may reduce the levels of flatulence factors.

• Applied Biological Chemistry
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• 제36권2호
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• pp.73-79
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• 1993

식물성 섬유질 함유 자원으로부터 식품의 가공적성을 떨어뜨리지 않으면서 우수한 기능특성을 보이는 식이섬유원을 제조할 목적으로 대량 수급이 용이한 사과쥬스박과 두유박에 식이섬유의 함량을 높이고 기능성을 향상시키기 위한 각종 처리를 행하여 식이섬유원을 제조하였다. 사과쥬스박은 마쇄, 수세 및 사별에 의하여 사과육과 사과피로 분리할 수 있었는데 사과육이 사과피보다 기능성이 우수하였고 사과육은 수세, n-hexane 처리 등에 의해 WHC 11.27 g/g, FHC 2.01 g/g, CEC 64.96 meq/100g의 기능성을 보이며 60.94%의 NDF를 함유한 제품을 제조할 수 있었다. 두유박을 이용한 식이섬유원 제조에서는 수세, n-hexane처리, 산처리, 알칼리처리 등의 처리로 WHC 10.15 g/g, FHC 1.52 g/g, CEC 63.72 meq/100g의 기능성을 보이며 52.66%의 NDF 함량을 갖는 식이섬유원이 제조되었다. 이때 원료로부터의 회수율은 사과육의 경우 약 30%, 처리두유박의 경우는 38.2%이었다. 식이섬유질원의 색도는 수세시 명도를 효과적으로 증가시킬 수 있었으나 유기용매, 산 및 알칼리 처리에 의해서는 명도가 감소하였다.

• Journal of Microbiology and Biotechnology
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• 제12권2호
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• pp.273-278
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• 2002

Two-step fed-batch fermentations were carried out to overproduce Bacillus licheniformis maltogenic amylase (BLMA) in recombinant Escherichia coli. The first step was to increase the cell mass by controlling the feeding of a glucose solution, while the second step was designed to improve the amylase expression efficiency by supplementing organic nitrogen sources. The linear gradient feeding method was successfully adopted to maintain the glucose concentration below 0.2 g/l during the fed-batch mode, as effectively minimizing acetic acid formation. When the dissolved oxygen (DO) level became limiting, an accumulation of acetic acid and drastic decrease in specific BLMA productivity were observed. Glucose and organic nitrogen sources consisting of yeast extract and casein hydrolysate were simultaneously supplied in the pH-stat mode to further increase the specific BLMA expression efficiency. An organic nitrogen source consisting of 200 g/1 yeast extract and 100 g/1 casein hydrolysate was found to be the best among the various combinations tested. The feeding of an organic nitrogen source in the second-step fed-batch period was highly beneficial in enhancing the BLMA production. The optimized two-step fed-batch culture resulted in 78 g/l maximum dry cell mass and 443 U/ml maximum BLMA activity, corresponding to 1.5-fold increase in the dry cell mass and 3.7-fold enhancement in BLMA production, compared with the simple fed-batch fermentation.

• 한국응용과학기술학회지
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• 제6권2호
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• pp.89-104
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• 1989

The purpose of the study was to find an effect of phospholipid-free vegetable oils on the serum lipids and proteins of Sprague-Dawley rats. All experimental rats were fed ad libitum for 60days with the mixture of starch: casein: salt mixture: vitamin mixture (60:18:4:1) and at the same time fed administratively with 1 ml of soybean oil, corn oil and sesame oil bought in market as source of phospholipid-free vegetable oils(PFVO) and those extracted directly by and oil press as source of phospholipid-containing vegetable oils(PCVO) respectively. At the last day of experimental period, the rats were fasted for 12 hours and decaptitated to collect blood for analysis of serum lipid and protein. The results of this study were summerized as follows. 1. The supplementation of dietary phospholipid decrease food efficiency ratio and the growth rate of experimental rats. 2. The supplementation of dietary phospholipid improve correlation coefficient of body weight and organ weights. 3. The supplementation of dietary phospholipid increase the level of serum phosphatidylethanolamine. Therefore, I think that we must eat dietary phospholipid unpurified from vegetable oil to prevent development of atherosclerosis and fat liver.

• Nutritional Sciences
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• 제7권3호
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• pp.138-143
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• 2004

Conjugated linoleic acid (CLA) has been shown to have a range of biological activities, including anti-carcinogenic, anti-atherosclerotic, anti-adipogenic and anti-diabetogenic effects. Recent reports also showed that CLA has free radical scavenging capacity, which may have health benefits for human beings. The current study was performed to investigate the effect of structured lipid (SL)-containing CLA on plasma lipids and hepatic antioxidant enzyme activity. Sprague-Dawley mts were fed 5% and 10% SL-containing normal diet for 6 wks and these groups were compared to rats fed 5% and 10% corn oil. In plasma lipids, total-cholesterol was not affected by fat source or dietary fat level while triglyceride level decreased significantly in groups fed 10% fat diet compared to the other groups. Plasma thiobarbituric acid reactive substances (TBARS) level decreased significantly in the S5 and S10 groups compared to the C5 and C10 groups, although hepatic TBARS level was not altered by fat source. On the other hand, in terms of hepatic antioxidant enzyme activity, superoxide dismutase activity increased in the S10 group, whereas catalase activity decreased in the S10 group. Glutathione peroxidase activity decreased significantly in the SL groups compared to the C5 group. Glutathione reductase activity increased and glucose-6-phosphate dehydrogenase activity decreased in the C10 group compared to the C5 and C5 groups. In conclusion, the free radical scavenging activity of CLA seemed to suppress oxidative stress, which reduced lipid peroxidation resulting in lower hepatic antioxidant enzyme activity.

• Fisheries and Aquatic Sciences
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• 제18권1호
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• pp.13-20
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• 2015

Calculated chemical scores (computed in relation to the FAO/WHO reference protein) for salmon liver protein hydrolysates indicated that all amino acids (other than methionine and threonine) were present in adequate or excess quantities; thus, the raw liver material is a good source of essential amino acids. The hydrophobic amino acids contents in hydrolysates prepared from Oncorhynchus keta and O. gorbuscha were 38.4 and 39.1%, respectively. The proportion of released peptides exceeding 500 kDa was reduced when hydrolysates were treated with the commercial enzyme Alcalase, although proportions in the following MW ranges were elevated: 100-500 kDa and <50 kDa. The optimal conditions for enzymatic hydrolysis were as follows: pH 7.0, $50^{\circ}C$, and a reaction time of 1 h. Of the different proteases tested, Alcalase was the most efficient for production of salmon liver hydrolysate with the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity. The hydrolysates prepared from salmon liver had a balanced amino acid composition. The liver protein hydrolysates contained low molecular weight peptides, some of which may be bio-active; this bio-active potential should be investigated. Inhibition of the DPPH radical increased with increased degree of hydrolysis (DH), regardless of protease type. DPPH radical scavenging abilities, antithrombotic effects and ${\alpha}$-glucosidase enzyme inhibition effects of O. keta liver hydrolysate increased in a dose-dependent manner. Thus, salmon liver hydrolysate may be useful in functional food applications and as a source of novel products.

• 농업과학연구
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• 제38권3호
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• pp.445-452
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• 2011

The object of this experiment was to investigate the food habits of Korean native goats fed with various roughage sources. The experimental trials were conducted at Unbong Animal Genetic Resources Station in 2008. The experimental roughages include five sources and 25 species in all; grasses and legumes: 5 species (mixed grasses, orchardgrass, tall fescue, alfalfa, white clover), native grasses and weeds: 5 species (mixed native grasses, Miscanthus sinensis Anderss, Arundinella hirta (Thunb.) Tanaka, Barnyard grass, short awn, forage crops and straw: 5 species (barley + hairy vetch, wheat + hairy vetch, rye silage, barley silage, baled rice straw), browse and fallen leaves: 5 species (Mixed browse, Oriental white oak, Quercus serrta Thunb., Oriental cherry fallen leaves, Japanese chestnut fallen leaves), and imported hay and straw: 5 species(timothy hay, tall fescue straw, annual ryegrass straw, klinegrass hay, alfalfa hay). Ten Korean native goats were selected which had nearly the same body weight (average $24{\pm}2.8$ kg). The chemical composition and dry matter digestibility of each roughage source and species were significantly different at the sampling area, plant species, growth stages and cutting period (p<0.05). Among all the 25 species of roughages, the favorite intake species order by Korean native goat was observed like this: Quercus aliena, Querancas serrta Thunb and Mixed browse, which was a lower intake compared to other domestic herbivores. The Korean native goats ate more roughages which had low fibrous contents, but high dry matter digestibility. The Korean native goats ate more roughages which had low fibrous contents, but high dry matter digestibility. On the other hand, compared to each roughage source, total intake amount by Korean native goats was showed as browse and fallen leaves (33.1%) among trials roughage sources. Based on these results, the food habit of Korean native goats seems to be closer to the browser.

• 농업과학연구
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• 제38권3호
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• pp.437-444
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• 2011

The object of this experiment was to investigate the food habits of sika deer fed with various roughage sources. The experimental trials were conducted at Unbong Animal Genetic Resources Station in 2008. The experimental roughages include five sources and 25 species in all; grasses and legumes: 5 species (mixed grasses, orchardgrass, tall fescue, alfalfa, white clover), native grasses and weeds: 5 species (mixed native grasses, Miscanthus sinensis Anderss, Arundinella hirta (Thunb.) Tanaka, barnyard grass, short awn, forage crops (hay, silages and straw): 5 species (barley + hairy vetch, Wheat + hairy vetch, rye silage, barley silage, baled rice straw), browse and fallen leaves: 5 species (mixed browse, oriental white oak, Quercus serrta Thunb., oriental cherry fallen leaves, Japanese chestnut fallen leaves), and imported hays and straws: 5 species (timothy hay, tall fescue straw, annual ryegrass straw, klinegrass hay, alfalfa hay). Five sika deer were used as experimental animals and the averaged body weight was 95+5.4kg. The chemical composition and dry matter digestibility of each roughage source and species were significantly different at the sampling area, plant species, growth stages and cutting period(p<0.05). The sika deer ate more roughages which had low fibrous contents, but high dry matter digestibility. Among all the 25 species of roughages, the favorite intake roughage sources ranking by sika deer was observed like this: browse and fallen leaves (32.2%), grass and legumes (27.0%), native grasses and weeds (22.0%), imported hays (12.9%) and forages crops (5.5%) respectively. Although, the sika deer ate more browse leaves, but ate more roughage which had low fibrous contents (NDF and ADF), but high drymatter digestibility. On the other hand, compared to each roughage source, total intake amount by sika deer was showed as browse and fallen leaves (32.2%). Based on the result, the food habit of sika deer seems to be closer to the typical browser.

• 한국식품과학회지
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• 제3권2호
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• pp.89-93
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• 1971

전국 각지의 토양 800점에서 총 1,506주의 균을 분리하였고 이들중에서 응유효소 생산균으로 20주의 균을 선정하였으며 교실보존 균들 중의 응유효소 생산균을 선정하여 응유효소 생산력을 비교하였으며 이들중 보존균 중의 Dothiorella ribis가 비교적 우수한 응유효소생산균임을 알고 이것을 밀기울에 배양할 때의 배양조건을 검토한 결과 밀기울에 대한 산수량은 $60{\sim]80%$ 산수의 pH는 4.0 정도, 질소원으로는 $(NH_4)_2SO_4$ 0.5%, 탄소원으로는 sucrose 3%정도, 무기염으로는 0.03%, 배양온도는 $30{\sim}35^{\circ}C$, 배양기간은 4일 정도가 적당함을 알 수 있었고 보다 장기간 배양하면 생성된 응유효소의 활성이 감퇴됨을 알수 있었다.