• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.201-203
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• 2003

In this study, succinic acid production using fumaric acid fermentation broth was investigated. We tried to produce fumaric aicd from glucose by Rhizopus oryzae and then convert fumaric acid fermentation broth into succinic acid by Enterococcus faecalis RKY1. Conversion ratio of succinic acid was more than 0.90 g/g-fumaric acid. Furthermore, we optimized conditions of conversion from fermentation broth. As a result, when fumaric acid fermentation broth for succinic acid production was employed, we could decrease the amount used of glycerol and yeast extract.

• 한국식품조리과학회지
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• 제20권6호
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• pp.598-606
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• 2004

The application of Dongchimi liquid to Naengmyon broth to improve its eating quality was scientifically explored by reviewing the quality of the product properties. Primarily, the optimum fermentation conditions for Dongchimi from which the liquid portion was extracted were pursued and the optimum mixing ratio sought on the basis of the product physicochemical properties. The liquid portions, periodically extracted from Dongchimi at intervals of two or five days, during fermentation at $10^{\circ}C$, were added to Naengmyon broth. The treatments were prepared at three levels namely, basic broth only ('A') and with ratios of Dongchimi liquid to basic broth of 3:7 (v/v, 'B') and 5:5 (vfv, 'C'). As a typical phenomenon of kimchi fermentation, a gradual decrease in the pH with increasing total acidity was observed as the fermentation of the Dongchimi progressed. At $10^{\circ}C$, the optimum ripening was obtained from day 8, and continued until day 15, when the pH was maintained at about 3.8 to 4.0. The total vitamin C and reducing sugar contents increased until the 13th-day of fermentation, but then decreased thereafter. The turbidity and solid content of the Dongchimi liquid increased with progression of the fermentation. With respect to the color values, the lightness (L) decreased, with increases in the redness (a), yellowness (b) and total color difference $({\Delta}E)$ during fermentation. Most of these observed phenomena for the Naengmyon broth substituted with $30\%$ (Treatment 'A') and $50\%$ (Treatment 'B') Dongchimi liquid, with different storage periods, confirmed the previous fermentation patterns of Dongchimi. A decrease in the pH with increasing total acidity, as well as gradual increases in the total vitamin C and reducing sugars (glucose and fructose) up to the 13th-day of fermentation were accompanied by subsequent declining patterns. The turbidity and solid content of the mixed broth also increased with increasing Dongchimi liquid fermentation period. With respect to the color of the mixed broth, the lightness was decreased, while the redness, yellowness and total color difference increased with increasing Dongchimi liquid fermentation period. It was also proven that the addition of slightly over-ripened Dongchimi liquid to the Naengmyon broth was more preferable.

• 한국균학회지
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• 제31권1호
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• pp.28-33
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• 2003

설탕을 이용한 고부가가치의 버섯 발효식품 제조시 최적 발효기간을 설정하기 위하여 발효기간의 경과에 따른 버섯 발효액의 품질특성과 효소활성 및 생리기능성의 변화를 조사하였다. 점도와 색상을 나타내는 L값, a값, b값 모두 3개월까지 급격히 감소한 후 증가하는 경향이었다. 관능특성은 발효기간이 증가함에 따라 고유의 냄새와 맛은 감소하고, 다른 맛과 냄새는 증가하는 경향이었으며, 전체적인 기호도는 발효 3개월 버섯 발효액이 제일 좋은 것으로 평가되었다. 버섯 발효액 중의 ${\alpha}-amylase$ 활성은 발효 1개월까지 급격히 증가하였고, invertase와 cellulose는 대부분 활성이 낮거나 없었다. 항산화할성은 발효 4개월에 가장 높았고 그 이후에는 약간 감소하는 경향이었으며 tyrosinase 저해활성은 모든 시료에서 높은 활성을 나타내었고, 발효기간의 경과에 따라 변화가 없었다. SOD 유사활성은 팽이버섯 발효액에서 비교적 높은 활성을 나타내었으며, 발효기간에 따라서는 큰 변화가 없었다. 이상의 결과를 종합해 볼 때 설탕을 이용한 버섯 발효액 재품 생산시 최적 발효기간은 3-4개월 정도가 적합할 것으로 판단된다.

• 한국식품영양학회지
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• 제20권2호
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• pp.195-201
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• 2007

This study were investigated the changes in chemical components, quality characteristics of the fermented broth, and physiological functionality during fermentation period of fruit, vegetables, and medicinal herbs. pH and $^{\circ}$Bx gradually decreased and the viscosity increased. The chromaticity of L, a, and b all increased. The total number of germs dropped from $10^5{\sim}10^6\;to\;10^2{\sim}10^3$ CFU/ml, and that of lactobacilli also decreased noticeably. According to the result of the effect on fat oxidation, a very low level of TBARS was shown. After thirty days of fermentation, the amount of each fermentation broth increased more or less, but as it declined considerably after ninety days, it was found that the binding effect of $Fe^{2+}$ ion was small and insignificant. The electron donating ability, though not reaching 0.5% ascorbic acid, showed a high level of activity from $33.71{\sim}72.15%$ before fifteen days and $44.76{\sim}75.20%$ ninety days after fermentation. Among them, the fruit fermentation solution showed the highest activity. It was also found that the organic functions for each fermentation broth decreased more or less depending on the fermentation period and the thirty-days-old fermentation broth were favored most. On the basis of the above experiment results, it can be concluded that the optimum fermentation period for fruit, vegetables, and medicinal herb is thirty to ninety days.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권6호
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• pp.500-505
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• 2004

The present study was to investigate the purification of a fermentation broth by an electromicrofiltration membrane. Microfiltration runs with a crude and a centrifuged broth, with solution of particles recovered from centrifugation and with permeates from microfiltration experiments were thus compared. Microfiltration performances were governed by colloids and small particles that induced sharp initial flux declines. For these results, the evolution of the overall membrane resistance was increased by $80\%$ in comparison with the electromicrofiltration membrane. The main focus of this study was set on the enhancement of the filtrate flux by an electric field. This pressure electrofiltration leads to a drastic improvement of the filtration by $100\%$ and the filtration time was thereby reduced. Pressure electrofiltration serves as an inter­esting alternative to the cross-flow filtration and it effectively separates advantageous constitu­ents such as amino acids and biopolymers from a fermentation broth. They were equally main­tained during the microelectrofiltration, although they were significantly reduced by $45\%$ by the microfiltration without the application of an electric field. Accordingly, since the electrofiltration membrane was provided more permeability, this study experimentally demonstrates that the permeability inside a membrane can be controlled using an electric field.

• 한국식품저장유통학회지
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• 제13권4호
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• pp.457-464
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• 2006

단백질원으로 참치자숙액 1, 3, 5%를 원료에 첨가하여 고추장을 제조한 후 이화학적변화를 측정하였다. 숙성 중 고추장의 pH는 참치자숙액 첨가량에 관계없이 감소하였고, 적정산도는 증가하였다. 숙성 30일 후 아미노태질소 함량은 대조구 171.59 mg%에서 참치자숙액 5% 첨가의 경우 191.10 mg%로 증가한 후 감소하였다. 환원당 함량은 모든 시료에 있어서 숙성 30일에 최대치를 보였다가 감소하는 경향을 보였는데 대조구에 비해 참치자숙액을 첨가한 시료가 높았다. 숙성 중 $\beta-amylase$ 역가 또한 숙성 30일에 최대치를 보였다가 감소하였다. 유리아미노산 함량은 참치 자숙액 첨가량의 증가와 더불어 증가하였다. Hunte L, a, b 간은 고추장의 숙성 중 감소하였으며, 숙성 90일 후 관능검사 결과는 참치자숙액을 첨가한 고추장이 대조구에 비해 관능적으로 우수함을 보였다.

• Korean Chemical Engineering Research
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• 제44권1호
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• pp.52-57
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• 2006

에탄올과 함께 탄소, 질소원을 함유한 맥주 폐 발효액을 저렴한 대체배지로 사용하고 Gluconacetobacter hansenii PJK(KCTC 10505 BP) 균주를 이용하여 미생물셀룰로오스를 생산하였다. 맥주 폐 발효액은 기본배지보다도 탄소원과 질소원이 풍부하였으며 미량의 황과 4％ 이상의 에탄올을 함유하였다. 진탕배양에서 맥주 폐 발효액을 사용하여 생산된 셀룰로오스량은 기본배지를 사용하여 생산된 셀룰로오스량과 필적하였다. 교반배양에서는 셀룰로오스 생산균주($Cel^+$ 균주)가 셀룰로오스를 생산하지 못하는 균주($Cel^-$ 돌연변이주)로 전환되는 률은 낮았지만 셀룰로오스 생산량은 감소하였다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.45-46
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• 2000

After cell removal from fermentation broth the supernatant containing poly (${\gamma}-glutamic acid$) (${\gamma}-PGA$) was concentrated by ultrafiltration in order to reduce the amount of organic solvents such as methanol, ethanol, propanol required for the recover of ${\gamma}-PGA$ with precipitation. The concentration and volume reduction of cell-free solution by ultrafiltration could reduce 3 times the amount of ethanol for the recover of ${\gamma}-PGA$ from cell-free fermentation broth.

• 한국미생물·생명공학회지
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• 제27권1호
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• pp.62-69
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• 1999

Clostridium butyricum NCIB 9576 evolved hydrogen gas and produced various organic acids from glucose, lactose, starch, and glycerol. Total amount of hydrogen gas produced from 1 and 2% glucose were 630 and 950ml $H_2$/l-broth, respectively, for the first 24 hrs of incubation and the maximum hydrogen production rates were 42 and 94ml $H_2$/hr/1-broth, respectively. Teh initial pH 6.8 decreased to 4.2~4.5 during the first 12~16 hrs of fermentation when the pH was not controlled, resulting in ceasing the cell growth and hydrogen evolution and in degradation of 82 and 40% glucose after 24hrs of incubation from 1 and 2% glucose, respectively. When pH was controlled to 5.5, glucose was consumed completely and resulted in increasing hydrogen production approximately 38~50% compared to the experiments without the pH control. C. butyricum NCIB 9576 produced hydrogen gas approximately 644, 1,700 and 3,080 ml $H_2$/l-broth with 0.5, 1 and 2% lactose, respectively and the maximum hydrogen production rates were 41, 141 and 179ml $H_2$/hr/l-broth, respectively. All of the lactose added was degraded completely during fermentation even though pH was not controlled. C. butyricum NCIB 9576 produced 183 and 709ml $H_2$/l-broth with 0.1 and 0.5% starch for 48 hrs, respectively, when pH was not controlled. The maximum rates of hydrogen gas production were 43 and 186ml $H_2$/l-broth, respectively and 80~100% of starch added was fermented. Approximately 107ml $H_2$/l-broth was produced using 1% glycerol by C. butyricum NCIB 9576 and the pH was maintained higher than 6.1 during fermentation without pH control. The degradation of glucose, lactose, starch and glycerol by C. butyricum NCIB 9576 were affected by the pH of fermentation broth and the organic acids released during fermentation. The pH of feremtntation broth dropped to 4.2~4.6 after 12~14 hrs incubation when glucose was used as a substrate while pHs were maintained above pH 5 under the same experimental conditions when lactose, starch and glycerol were used. The organic solvents and acids produced during glucose fermentation were mainly ethanol, butyrate, acetate and a little of propionate, while butyrate was the main organic acids during the lactose, starch, and glycerol fermentation by C. butyricum NCIB 9576.

• 한국식품영양학회지
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• 제12권5호
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• pp.455-461
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• 1999

The possibility of wine making from soft and dried persimmon and the effects of treatment for persimmon on the quality of wine have been investigated. Soft persimmon was pretreated by two method of heat and hydrochloric acid treatment. Fermentation mash was composed of 12% persimmon and 15% of sucrose and was fermented at 17$^{\circ}C$ for 36 days. The fermentation using persimmons which were untreated and treated by acid was not successful because of contamination caused by lactic acid and acetic acid bacteria. Acidity of the fermented broth produced from boiled dried acid treated and untreated persimmon was 4,4, 5.0, 5,8 and 13.5ml(0.1N NaOH/10ml broth) respectively. Ethanol concentration of the fermented broth produced from boiled dried acid treated and untreated persimmon was 11.2, 10.0, 9.4 and 6.1% v/v respectively. The wine fermented for 28day's fermentation using boiled persimmon as substate had the best quality and stability. After 36day's fermentation using boild persimon following composition was obtained: 4.65% of total sugar 3.65% of reducing sugar 0.03mg/ml of protin 0.17$\mu$/ml of amino acid and 13.02 $\mu$g/ml of pectin. The pH and yeast cell of the boiled persimmon broth were 3.4 and 5.75 logCFU/ml. Fermented wine using dried persimmon had aslo good quality but the fermentation rate was slow.