• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 1974.06a
• /
• pp.125.2-125
• /
• 1974

맥주의 품질에는 영향을 주지 않고 발효의 기능을 증가시키기 위하여 현행의 9일계원분발효실험을 3일-6일 또는 3일-5일의 이단변로 나누어 연속적으로 발효를 시킬 경우의 맥주의 산화를 연구해본 결과 한 결과가 기초되었다.

• Transactions of the Korean hydrogen and new energy society
• /
• v.17 no.1
• /
• pp.98-108
• /
• 2006

본 연구에서는 이 단계 연속 바이오 수소/메탄 생산공정의 경제성을 조사하였다. 경제적 관점에서 다양한 수소 및 메탄 발효용 생물반응기를 비교 평가하였다. 이를 바탕으로 포도당으로부터 일 단계 수소발효를 위해 고온 trickling biofilter 반응기 (TBR, $100\;m^3$ 규모)를, 일 단계 반응의 부산물로 생성된 유기산과 알콜류의 이 단계 메탄전환을 위해 고온 upflow anaerobic sludge 반응기 (UASB; $700\;m^3$ 규모)를 선정하였다. 본 이 단계 공정의 수소생산 비용은 $$\;0.26/Nm^3$으로 계산되었고, 이는 고온 TBR 반응기만을 이용한 경우보다 약 30 % 낮았다. 이 단계 공정의 낮은 수소생산 비용은 높은 에너지 회수율과 낮은 슬러지 처리비용에 의한 것이었다. 생물학적 수소 생산공정의 경제성은 탄소원의 종류, 생물반응기의 형태 등 여러 인자에 의해 변경될 수 있으나, 본 연구결과는 향후 연구를 위한 유용한 기준으로 고려될 수 있다.

• Microbiology and Biotechnology Letters
• /
• v.3 no.2
• /
• pp.89-93
• /
• 1975

In order to ferment beer more effectively under conditions similar to the conventional batch fermentation, a part of the wort which had been fermenting for three days was replaced with un-pitched fresh wort and completed the rest of the fermentation in four to six days. The taste test panel accepted the beers fermented for five days after diluting with one third or one half volume of freshl wort giving fermentation efficiency gains by 22％ or 28％ over the regular nine-day batch fermentation respectively.

• Microbiology and Biotechnology Letters
• /
• v.3 no.1
• /
• pp.31-34
• /
• 1975

Fermentation models of beer having higher efficiencies with a minimum change in conventional batch fermentation condition have been designed. By diluting the fermenting mass with one half or one third volume of fresh wort after three days of the conventional batch fermentation and completing the rest of the fermentation in five or four days, about 20 to 30 percent increase in the fermentation efficiency over the regular 9-day batch beer fermentation is theoretically feasible.

• Microbiology and Biotechnology Letters
• /
• v.10 no.2
• /
• pp.155-162
• /
• 1982

A cell-recycled continuous fermentation process was studied to produce ethanol from molasses using Sacchoromyces uvarum ATCC26602 at 35 $^{\circ}C$. The fermentation system was divided into two stages in order to reduce the inhibitions of ethanol and substrate for cell growth and fermentation rate. The first reactor was aerated at the rate of 0.12 vvm whilst the second was kept anaerobic. In medium composition studies, it was revealed that inorganic nutrient supplement to the diluted molasses with 14% fermentable sugar was not needed for the fermentation, however, phosphate limitation was observed when cell propagation was contemplated. By using the cell-recycled continuous fermentation system, 14.5 hour was required to produce 8.4-9.0% (v/v) of ethanol from diluted molasses containing 14% of fermentable sugar. The ethanol productivity was 6.2g/$\ell$hr with the yield of 88.1-94.4% to the theoretical value.

• Applied Biological Chemistry
• /
• v.16 no.2
• /
• pp.85-93
• /
• 1973

These experiments were carried out to study influences of the kind of yeasts and of brewing condition on fermentation of Takjoo mash. The results obtained were as follows: 1. Kind of yeasts and the number of yeasts in mash. When the first stage mash was fermented at $20^{\circ}C$ for $1.5{\sim}2.5$ days and at $25^{\circ}C$, $30^{\circ}C$ for $1{\sim}2days$, in the second stage mash that was fermented at high temperature, the number of yeasts was less as compared with the case of fermentation at low temperature, but the living yeasts number of Takjoo yeast strain Dm-1 was more than those of sake yeast, strain No. 7. 2. Kind of yeasts and composition of ripened mash. 1) In the secondstage mash that was fermented at high temperature($30{\sim}35^{\circ}C$), alcohol percentage of ripened mash using the selected Takjoo yeasts (strains: Dm-1, Y-1) was remarkably higher than the case of another yeasts (strains: No.7, No.6, No. 396, No. 1). 2) Acidity of mash had a little differences between strain Dm-1 and strain No. 7. 3) In the second stage mash that was fermented at high temperature ($30{\sim}35^{\circ}C$), the amount of Formol-N using strain Dm-1 was remarkably less than strain No.7. 3. Brewing condition and alcohol percentage of mash. 1) The fit amount of wheat bran Kuk addition per material was 3 percentage and it was adequate to use the mixture of wheat flour Kuk 20 percentage and wheat bran Kuk 1-2 percentage. 2) Though brewing concentration of the first stage mash was duiluted by twice of general brewing concentration, the yeast reproduction was normal. 3) In addition of wheat flour $80{\sim}140g$ per 180ml water, alcohol percentage of the mash increased almost propotionally according to the increase of the amount of wheat flour. 4) It was recognized that three stage brewing was superior in method to two stage brewing at present.

• KSBB Journal
• /
• v.24 no.5
• /
• pp.489-494
• /
• 2009

Two-step pretreatment process was investigated to efficiently hydrolyzed rape stems for obtaining fermentable sugars. The process was consisted of two consecutive steps as $200^{\circ}C$ and 15 MPa and $374^{\circ}C$ and 24 MPa with the flow rate of 5 mL/min. Under this condition, 5.5 (g/L) of glucose and 25.6 (g/L) of xylose were obtained from rape stems, showing 18% of glucose yield based on 25% cellulose in the rape stems. It was also found that this process could generate less amounts of toxic residues, such as HMF (Hydroxy- Methyl-Furfural) and other fulfural components during hydrolysis process. It could reaction maintain relatively high ethanol production yield as 90% of theoretical conversion yield from glucose. Therefore, this pretreatment process could be applied to hydrolyze other cellulosic and marine resources such as woods, stem and algae for bioethanol production.

• KSBB Journal
• /
• v.5 no.1
• /
• pp.9-17
• /
• 1990

The growth and fermentation profiles of Clostridium acetobutylicum KCTC 1037 were examined in batch and continuous modes with pH variation and phosphate limitation. Clostridium acetobutylicum KCTC 10 37 grew better at pH 4.5 than at pH 5.5 or 6.5. Acetate and butyrate were produced at pH 5.5, whereas culture at pH 4.5 produced acetone and butanol. Solvent production was increased by the phosphate limitation in a batch culture, but in a phosphate-limited continuous culture for 400 hours steady-state solventogenesis was not observed. The induction and maintenance of solventogenesis presumably require not only acidic condition or phosphate limitation but also favourable bioenergetic condition.

• Applied Biological Chemistry
• /
• v.28 no.2
• /
• pp.98-105
• /
• 1985

In the sheep and cattle's rumen, facultative anaerobic cellulolytic bacteria were isolated by using Hungate's roll tube technique. In the 21 isolated species, one was screened by its strong cellulolytic activity and identified as Cellulomonas fimi C-14 by investigate morphological, cultural, physiological characteristics and electron microgram. Optimum conditions of the cell growth and enzyme production were pH 6.5 an $30^{\circ}C$, Thiamine and biotin support a good growth of C. fimi C-14. In the enzyme activities, Crystalline cellulose hydrolyzing activity, CMCase activity and ${\beta}-glucosidase$ activity were 20.6, 226.6 and 0.56$(unit{\times}10^3/ml)$ at pH 6.0, $40^{\circ}C$. By addition of fungal cellulase, enzyme activity was increased. Simultaneous Saccharification Fermentation is better than two step fermentation in ethanol yield with Saccharomyces cerevisiae DY2.

• Korean Journal of Food Science and Technology
• /
• v.29 no.5
• /
• pp.895-900
• /
• 1997

Cyclodextrin (CD), which is one of food additives, was applied to Takju in oder to suppress the production of a stinking odor which its brewing and storage. CD was added to Takju in two different manners: one right after its brewing dilution stage, the other during its second mashing stage. After equal intervals of time, each sample was tested for fermentation process, storage capability, and sensory characteristics. The amount of CD ranged from 0.1 to 0.3% (w/w). The effect of CD on alcohol concentration, pH, total acidity and sugar content of Takju was shown to be more greatly influenced in the second sample rather than the first. The qualities of Takju were not affected by the addition of CD in the first sample. The sensory evaluation showed that the sample of the brewing dilution stage proved to be more attractive in the level of acceptability. However, when CD was over-added to Takju, the degree of acceptability declined due to the fact that the over-addition of CD suppresses its unique taste and flavor.