• Korean Journal of Food Science and Technology
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• v.35 no.4
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• pp.708-712
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• 2003

This study was carried out to examine the effects of fermentation conditions on the production of erythritol by osmophilic yeast Candida magnoliae. It was found that sucrose was superior to glucose as carbon source and 109 g/L erythritol was produced from 400 g/L sucrose. When yeast extract was used as nitrogen source, maximum values of yield and productivity for erythritol were obtained at 15 and 20 g/L of yeast extract, respectively. A mixture of 15 g/L yeast extract and 3 g/L ammonium phosphate allowed more efficient utilization of sucrose and hence resulted in 149 g/L of erythritol, 0.37 g erythritol/g sucrose of erythritol yield and $0.78\;g/L{\cdot}hr$ of erythritol productivity. A batch fermentation supplemented with 40 g/L KCl resulted in an erythritol concentration of 167 g/L and an erythritol yield of 0.42 g erythritol/g sucrose.

• KSBB Journal
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• v.16 no.5
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• pp.474-479
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• 2001

Fed-batch culture, single stage and two stage continuous cultures of Corynebacterium glutamicum SH 35 for the production of $_{L}$-Iysine were performed and compared. In the case of fed batch culture, $_{L}$-Iysine concentration, $_{L}$-Iysine yield and $_{L}$-Iysine productivity was 129.2 g/L, 47.0% and 3.08 g/L/h, respectively. In a single-stage continuous culture, optimum dilution rate and pH was 0.1 h$^{-1}$ and 6.9, respectively, and optimum concentration of sugar and ammonium sulfate in a medium reservoir was 108 g/L and 25 g/L, respectively. Under the optimized conditions, 67 of cell concentration($OD_{610}$), 44.2 g/L of lysine concentration, 41% of $_{L}$-Iysine yield and 4.39 g$L^{-1}$ of $_{L}$-Iysine productivity were obtained. In a two-stage continuous culture, optimum dilution rate was 0.075 $h^{-1}$. Under the conditions, 103 of cell concentration($OD_{610}$) 84.0g/L of $_{L}$-Iysine concentration and 46% of $_{L}$-Iysine yield were obtained.

• KSBB Journal
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• v.9 no.2
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• pp.122-126
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• 1994

A new method for the production of isomalto-oligosaccharides from maltose was investigated using intact cells of Aureobasidium pullulaans which had been known to produce fructo-oligosaccharides. The cells showed transglucosylation activity producing isomalto-oligosaccharides at high concentrations of maltose, while they showed a hydrolytic activity at low concentrations of substrate when cultivated at $25^{\circ}C$. The optimum reaction conditions for the isomalto-oligosaccharide production were as follows: substrate concentration, 500g/l maltose; pH, 4.5; temperature, $65^{\circ}C$; cell dosage, 10 unit per gram substrate. Under optimized conditions, the maximum yield of isomalto-oligosaccharides achieved was around 48% (w/w). At the early period of reaction, panose was selectively produced from maltose, and thereafter isomaltotriose was synthesized by utilizing panose as a substrate when maltose consumption was discontinued.

• Journal of Life Science
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• v.20 no.11
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• pp.1691-1696
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• 2010

Neohesperidin is a natural new nutrition sweetener, widely existing in plants of dry citrus peel, which can be derived from extraction. Since the sweetness is 1,300-1,500 times greater than that of sugar, neohesperidin are widely used in fruit juices, wines, beverages, bakeries and pharmaceutical formulations, and are particularly suitable for consumption by diabetic patients. However, the yield of extraction from citrus peel waste is very low. In this study optimal yield conditions were determinedusing response surface methodology (RSM) in order to increase the neohesperidin extraction yield. The critical factors for maximum extraction yield were selected extraction pressure ($x_1$), extraction time ($x_2$), and concentration of ethanol ($x_3$). As a result, the extraction yield was improved when the extracting pressure increased. The extraction yield also increased in a time-dependent manner. When adding ethanol as an assistance solvent to the supercritical carbon dioxide, extraction yield was increased as more ethanol concentration was added. Finally, the extraction yield of neohesperidin was improved to about 162.22% compared to ethanol extraction as a conventional method.

• Microbiology and Biotechnology Letters
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• v.17 no.4
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• pp.379-384
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• 1989

Glutamine production from glutamate was carried out using glutamine synthetase from E. coli K-12 pgln 6 and baker's yeast, which supplies ATP into the reaction system through alcohol fermentation, simultaneously. With whole cells of E. coli K-12 pgln 6 as an enzyme source of glutamine synthetase, 11.8 g/ι of glutamine produced after 18-h incubation (60％ yield based on a substrate, glutamate). Using the partially purified glutamine synthetase, 19.8 git of glutamine was produced after 5-h incubation. This amount of glutamine was correspond to 90％ yield, based on substrate, glutamate.

• KSBB Journal
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• v.17 no.2
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• pp.182-188
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• 2002

Enterococcus faecalis RKY1 cells were immobilized in an asymmetric hollow fiber bioreactor for application to the continuous production of succinic acid. The media was fed into shell-side of the module using a peristaltic pump, and the products were collected through lumen-side outlet. The number of hollow fibers within the module did not affect the bioreactor efficiency in the transverse operated hollow fiber bioreactor. The steady state at the outlet of hollow fiber bioreactor was reached after 24 hr cultivation at flow rate of 0.25 mL/mim, 12 hr at 0.5 L/min, and 9 hr at 1.0 mL/mm, respectively. The succinate and fumarate concentrations within the hollow fiber bioreactor, however, were as changeful as increasing the flow rate. During continuous operation with the flow rates between 0.5 and 2.0 mL, the productivity of succinate was 8.0-10.9 g/L $.$ hr at 30 g/L fumarate, 4.9-14.9 g/L hr at 50 g/L fumarate, and 7.2-17.1 g/L hr at 80 galL fumarate, respectively.

• Korean Journal of Food Science and Technology
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• v.13 no.3
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• pp.247-252
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• 1981

As a primary study for the improvement of yield and preference of soybean sprouts, the water absorption rates by soaking and the growing characteristics of sprouts were investigated. When the soybeans were soaked in subterranean water at $18^{\circ}C$ for 4 hours, water absorption rates by weight percent of soybeans were ranged $167.0{\sim}194.5%$, and it means that the absorption rates do not greatly influence its germination rates. The yield of soybean sprout whose common name is Guryetai and of the sprout treated with 1 ppm Gibberellin marked the highest value, 837% and 585%, respectively. In case of industrial cultivation of soybean sprout, it is supposed that sprinkling with subterranean water is good for prevention of deterioration by growth of microorganisms and respiratory heat.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.04a
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• pp.125.1-125
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• 2003

호박은 다른 과채류에 비해 기후조건에 대한 적용범위가 넓고, 한국의 기후 풍토하에서 잠재생산 가능성이 대단히 높은 작목의 하나로 간주되고 있으며, 다른 박과 채소보다 병이 심하지 않고 약재를 살포할 필요가 거의 없으므로 무공해 식품으로도 그 가치가 높은 것으로 평가되고 있다. 최근 국민 식생활 패턴이 고급화 됨에 따라 건강을 중요시하는 소비자가 급증하면서 약품이 아닌 식품으로 인체의 조절기능에 초점이 맞춘 다양한 기능성 식품이 생산되고 있는 실정이며, 이 중 녹황색 채소류의 항산화, 항암효과가 알려지고 있어 늙은 호박을 이용한 새로운 형태의 가공제품은 향후 소비자의 구매욕구를 충동하기에 충분할 것으로 판단된다. 따라서 이러한 호박을 이용하여 가공제품을 생산하기 위한 기초자료로서 추출조건에 따른 품질변화를 모니터링하고자 하였다. 호박의 전처리의 경우 박피유무에 큰 차이가 없으므로 공정단계를 최소화하기 위해 박피를 하지 않고 사용하였으며, 파쇄의 형태는 깍둑썰기(4$\times$4$\times$4㎤)를 하여 추출조건에 사용하였다. 추출온도의 경우 호박자체의 색을 유지하는데 효율적인 95$^{\circ}C$에서 행하였다. 시료에 대한 용매비 및 추출시간에 따른 품질의 변화가 많으므로 시료에 대한 용매비(10, 20, 30, 40 50g/100$m\ell$) 및 추출시간(1, 2, 3, 4, 5 hr)에 따른 중심합성실험계획으로 추출하였다. 추출조건에 따른 추출물에 대하여 수율, 당도, 갈색도 및 탁도를 측정하여 시료에 대한 용매비 및 추출시간에 따른 반응표면분석을 실시하였다. 영향도를 분석한 결과 수율은 추출시간에 영향을 많이 받는 것으로 나타났으며, 총당 및 갈색도는 시료에 대한 용매비에 영향을 많이 받으며 탁도의 경우 두 조건 모두에 영향을 받은 것으로 나타났다. 수율에 대한 최적 추출조건은 호박량 10.03% 및 추출시간 2.89hr일 때 가장 높은 수율로 예측이 되었으며, 갈색도의 경우 호박량 15.21% 및 추출시간 1.65hr에서 최소로 나타났다.

• KSBB Journal
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• v.14 no.2
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• pp.205-211
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• 1999

We investigated optimal conditions for the microbial transformation of $\gamma$-butyrobetaine into L-carnitine by using Achromobacter cycloclast ATCC 21921. When the cells were cultivated in the medium containing $\gamma$-butyrobetaine as the sole carbon source for both cell growth and L-carnitine production, the maximum L-carnitine production was 2.9 g/L and the conversion yield from $\gamma$-butyrobetaine to L-carnitine was as low as 30.9 mol%. In order to enhance the L-carnitine production and the conversion yield, various carbon sources were added to the $\gamma$-butyronetaine containing basal medium. In the medium supplemented with glycerol, L-carnitine production was as high as 4.6 g/L and the conversion yield was 88.2 mol%, showing a significant improvement in L-carnitine synthesis compared to those in the medium without glycerol. We also examined the additional effect of quaternary ammonium compounds such as betaine and choline, which are similar in structure to $\gamma$-butyrobetaine and L-carnitien. It was observed that in the presence of those quaternary ammonium compounds, both the L-carnitine production rate and the conversion yield increased. In addition, we found that cell growth was inhibited by a $\gamma$-butyrobetaine concentration of more than 3%, while L-carnitine production was efficient at the $\gamma$-butyrobetaine concentration of 2-3%. By cultivating the cells in the optimal medium containing glycerol and choline, we obtained an L-carnitine concentration of 7.2 g/L with the conversion yield of 98.7 mol% in 4 days.

• KSBB Journal
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• v.14 no.5
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• pp.539-542
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• 1999

For the mass production of DFAIII and for the development of techniques of separation and purification of it, the methods of production of DFAIII and its recovery was investigated by fermentation with the strain of Arthrobacter ureafaciens KCTC 3387 and by enzyme reaction. In the first method, DFAIII was produced by fermentation with the strain of Arthrobacter ureafaciens KCTC 3387 and recovered from culture supernatant with silica gel gy filtration, in the second method, it was produced by enzyme reaction and recoverd with the same method of the first, and in third method it was produced by fermentation and recovered by addition of ethanol to the culture supernatnat.Against 25g/L of initial concentration of inulin, 1.57, 4.40, 0.34 g/L of powder of DFAIII was recovered respectively and the rate of recovery was 6.3, 17.6 1.4% and the purity was estimated at 81, 97, 87% respectively. For the production of DFAIII and its recovery, enzyme reaction method was the highest in the rate of recovery and its purity. By fermentation method, DFAIII was produced with 50% fo initial concentration of substrate but th rate of recovery was lower than enzyme reaction method and purity was lowest among the three methods. Ethanol pricipitation method showed the lowest rate of recovery.