• Food Science and Biotechnology
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• 제18권4호
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• pp.939-947
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• 2009

In order to produce vinegar using onions, 12 acetic acid bacteria were screened from the juice of fallen peaches, and a strain showing the highest acetic acid productivity among them was selected and identified as Acetobacter tropicalis No. 22. The culture broth containing 2.5%(w/v) of initial sugar concentration showed maximum acetic production after 10 days of cultivation, and the acetic acid was produced at the highest rate and reached the maximum acidity after 2 to 6 days of cultivation when the residual sugar and the ethanol concentration were in the range of 1.6 to 2%(w/v) and 0.6 to 1.8%(v/v), respectively. Also optimum conditions for acetic acid production by response surface method using the fractional factorial design with 3 variables and 5 levels were involved with initial ethanol content of 4.67%(v/v), initial acidity of 0.03%, and initial glucose concentration of 2.35%(w/v) and predicted level of acetic acid production at these conditions was 3.77%.

• Journal of Microbiology and Biotechnology
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• 제19권2호
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• pp.167-171
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• 2009

The effects of culture conditions on succinic acid production and its possible scale-up have been studied. Mannheimia succiniciproducens LPK7, engineered for enhanced production of succinic acid and reduced by-product secretion, was used for the experiments. Mannheimia succiniciproducens LPK7 is a knock-out strain of wild type deficient in the ldhA, pflB, and pta-ackA genes, and is derived from Mannheimia succiniciproducens MBEL55E. Process optimization of factors including optimal temperature, pH, carbon source, and nitrogen source was performed to enhance the production of succinic acid in flasks. To observe scale-up effects, batch fermentation was carried out at various working volumes. At a working volume of 7.0 l, the final succinic acid concentration and yield were 15.4g/l and 0.86g/g. This result shows similar amount of succinic acid obtained in lab-scale fermentation, and it is possible to scale up to larger fermentors without major problems.

• 한방안이비인후피부과학회지
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• 제31권1호
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• pp.32-41
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• 2018

Objectives : Hyaluronic acid(HA) is a mucopolysaccharide, occuring naturally in living organisms. It is one of the most hydrophilic molecules, so it has been known as being related to skin hydration and skin aging. The purpose of this study is to examine the effects of Angelica gigas(A. gigas) ethanol extract on hyaluronic acid synthesis. Methods : To determine cytotoxicity and hyaluronic acid synthase 2 gene expression, hyaluronic acid production in HaCaT cells, MTT assay and RT-PCR ELISA was used. Results : There were no cytotoxicity in $50{\mu}g/ml$ concentration A. gigas extract in MTT assay. Hyaluronic acid synthase 2(HAS2) gene expression was increased by all treated concentration A. gigas extract. Hyaluronic acid production was higher than control group in $50{\mu}g/ml$ & $100{\mu}g/ml$ concentration A. gigas extract. Conclusions : Hyaluronic acid production was increased by A. gigas extracts. Therefore, We suggest that A. gigas can make a contribution to the moisturizing effect on human skin.

• Applied Biological Chemistry
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• 제38권1호
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• pp.31-36
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• 1995

Monascus색소 주탄소골격의 생성 메카니즘을 연구하고, 새로운 개시체가 색소 생합성에 미치는 영향을 연구하고자 적절한 중간체와 개시체를 투여하였다. 크로톤산과 소르브산은 낮은 농도에서 균체의 증가 없이 색소 형성을 촉진하였다. 소르브산이나 그의 에틸에스테르를 투여하였을 때에는 크로톤산의 경우보다 약 2배 색소형성이 많았다. 이외에도 신남산과 비닐아크릴산을 개시체로 투여하였을 때에는 색소 혼합물은 암적색으로 나타났으며 색소의 형성은 감소하였다. 그러나 에틸에스테르로 변환시켜 투여하였을 때에는 색소의 형성이 증가하였으며 이차원 TLC 결과 새로운 적색소가 생성되었음을 알 수 있었다.

• Applied Biological Chemistry
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• 제27권1호
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• pp.7-13
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• 1984

본 연구는 탈지대두분(脫脂大豆粉)에서 만든 대두유에 여러 가지 당(糖), 발육촉진물질, amino acid, 유제품부산물을 가하여 Lactobacillus acidophilus의 생육과 산생성에 미치는 영향을 관찰한 것으로서 그 결과를 요약하면 다음과 같다. 배양시간에 따른 유산균의 생육도를 측정한 실험으로부터 대략 12시간까지가 대수기인 것으로 나타났다. 본 실험에서 사용된 당(糖) 가운데 glucose와 fructose가 유산균에 의한 산생성에 현저한 효과를 보였으며, 그 적정농도는 각각 3% 정도였다. 첨가된 발육촉진물질 가운데 yeast extract가 유산균에 의한 산의 생성을 가장 촉진시켰으며 그 적정농도는 0.5% 정도였다. l-methionine의 첨가에 의하여 유산균에 의한 산생성이 감소하였다. 대두유에 첨가된 유청분말과 탈지분유는 유산균의 생육과 산생성 촉진 효과가 저조하였다. 대두 단백질의 농도를 달리했을 때 유산균의 생육과 산생성에는 차이가 없었다.

• 생명과학회지
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• 제16권1호
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• pp.6-11
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• 2006

Aspegillus niger 세포에 의한 구연산 생산에 대한 발효 매체로서 우유공장폐수가 연구되었다. 발효매체에 $Mn^{2+},\;Fe^{2+}\;and\;Cu^{2+}$의 첨가가 구연산 생산을 일정하게 증가시켰다. 그러나 다른 금속이온인 $Mg^{2+}$의 첨가는 구연산 생산을 감소시켰다. 구연산의 농도는 우유공장폐수에서 환원당 농도의 농도가 50 g/l와 100 g/1로 Aspegillus niger ATCC 9142에 의한 batch bioreactor에서 각각 7.2 g/1과 16.5 g/l로 높게 표시되었다. 본 실험에서 적용한 수리적 모델식들이 세포성장의 예상, 구연산 생산, 기질소모 속도에 대해 잘 적용되는지를 알아보기 위해서 발효반응 모델식에 적용시켜 본 결과 실험치와 잘 부합되었다.

• Animal Bioscience
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• 제34권1호
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• pp.119-126
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• 2021

Objective: This study aims to evaluate the effects of dietary supplement of rubber seed oil on production performance, egg quality, and yolk fatty acid composition in laying hens during a 16-week feeding trial period. Methods: Forty-eight 25-week-old laying hens of Hy-Line Brown were randomly divided into three groups. Each group comprised four replicates and each replicate had four birds. Rubber seed oil was incorporated into a corn-soybean meal basal diet by 3.5% (group I), 4.5% (group II), or 0 (control group) and equivalent nutrition was supplied for the test groups and the control group. The performance related values were determined using standard or well established methods. Results: No significant difference was found in the production performance, the egg quality, the composition of saturated fatty acids, and the content of cholesterol and monounsaturated fatty acids in the yolk within the three groups. Interestingly, both test groups achieved a significantly higher content of linoleic acid, α-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid and a significantly lower content of arachidonic acid (p<0.05) compared with the control group. With the increased level of dietary rubber seed oil, there was an increasing trend in the content of n-6 polyunsaturated fatty acids (PUFA), n-3 PUFA and total PUFA, but a declining trend in the n-6/n-3 ratio. Conclusion: These results demonstrate that the rubber seed oil supplemented diet effectively improved the total PUFA content in eggs without impairing the layers' production performance and the egg quality.

• 한국미생물·생명공학회지
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• 제19권1호
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• pp.70-75
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• 1991

Continuous and simultaneous production of gluconic acid and sorbitol from glucose and fructose was carried out by using glucose-fructose oxidoreductase and glucanolactonase of Zymomonas mobilis. In order to utilize the enzymes without purification, Zymomonas mobilis was permeabilized with toluene. Optimum conditions for permeabilization and reaction kinetics of permeabilized Zymomonas mobilis were studied. In batch operation with the permeabilized cells immobilized in alginate beads, about 90% conversion was obtained within 35 h reaction. Continuous production of gluconic acid and sorbitol using the immobilized permeabilized cells was carried out. Optimum conditions for continuous operation with the imn~obilized cells were; pH 6.2 and temperature $40^{\circ}C$. Maximum productivities for gluconic acid and sorbitol were about 14.5 g/l/h and 14.8 g/l/h respectively at the dilution rate of 0.075 $h^{-1}$ when 300 g/l each of substrates was fed.

• 산업기술연구
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• 제21권A호
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• pp.337-341
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• 2001

This study was carried out to screen the effective polymeric additives preventing wall growth during mycelial submerged cultivation of Ganoderma. lucidum. Effects of additives on mycelial growth and exo-polysaccharide (EPS) production in flask culture and jar fermenter system under 3 different pH processes were investigated, and changes of mycelial morphology were also examined. From flask culture of G. lucidum with additives of different concentrations, 0.1%(w/v) polyacrylic acid was effective for EPS production. As the polyacrylic acid of 0.1%(w/v) was added in medium, wall growth of G. lucidum mycelium grown in jar fermenter system could be protected. The addition of 0.1%(w/v) polyacrylic acid to medium was also improved the mycelial growth and EPS production in the later of submerged culture G. lucidum and no changes of mycelial morphology were observed.

• 한국식품영양과학회지
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• 제28권4호
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• pp.805-809
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• 1999

The growth of Lactobacillus casei in milk was enhanced by adding yams. Addition of 1% yam(raw or dry) promoted the cell growth and acid production in fermented milk. The milk containing 1% yams formed the complete curd by lactic acid fermentation at 37oC for 19hr while the milk without yams showed the incomplete curd formation. The crude mucilage extracted from a raw yam also enhanced the cell growth as well as the acid production. Addition of mucilage(0.08%) showed the similar effects with adding heat treated yam(1%). The milk fermented by adding various yams showed the high scores for sensory evaluation comparing with the milk fermented without yams. The fermenting ability of Lactobacillus acidophilus, Lactobacillus kefir and Leuconostoc mesenteroides was evaluated by adding 1% of a dry yam in milk. A dry yam also enhanced the cell growth of L. acidophilus resulting in the high acid production. The viable cell counts of L. casei, L. acidophilus and Leuc. mesenteroides except L. kefir were increased by adding 1% of a dry yam.