• 한국미생물·생명공학회지
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• 제17권2호
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• pp.165-169
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• 1989

고생산성의 알콜 발효용 생물반응기를 개발하기 위하여 sodium alginate로 효모균체를 고정화시킨 후 충전탑 반응기를 제조하였다. 이 때 gel속에 고정화되어 있는 세포에 산소를 공급하기 위하여 배지를 공기로 포화시킨 후 공급하였다. 그 결과 9% 포도당을 함유한 배지를 사용하였을 경우 최대 알콜생산성은 35g/$\ell$-gel-hr에서 55g/$\ell$-gel-hr로 증가되었고 90%의 전환율을 얻는데 걸리는 시간도 40분에서 25분으로 감소되었다. 즉 고정화세포 충전탑 반응기에서도 배지에 어느 정도의 산소를 공급하면 세포활성의 증가로 발효속도가 현저히 촉진됨을 알 수 있었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제3권1호
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• pp.15-18
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• 1998

The entanol productivity of superoxide dismutase (SOD)-deficient mutants of Saccharo-Myces cerevisiae was examined under the oxidative stress by Paraquat. It was observed that MnSOD-deficient mutant of S. cerevisiae had higher ethanol productivity than wild type or CuZnSOD-deficient yeast both in aerobic and in anaerobic culture condition. Pyruvated dehydrogenase activity decreased by 35% and alcohol dehydrogenase activity increased by 32% were observed in MnSOD-deficient yeast grown aerobically. When generating oxygen radicals by Paraquat, the ehanol productivity was increased by 40% in CuZnSOD-deficient or wild strain, resulting from increased activity of alcohol dehydrogenase and decreased a activity of pyruvate dehydrogenase. However, the addition of ascorbic acid with Paraquat returned the enzyme activities at the level of control. These results imply that SOD-deficiency in yeast strains may cause the metabolic flux to shift into anaerobic ethanol fermentation in order to avoid their oxidative damages by Paraquat.

• KSBB Journal
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• 제5권2호
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• pp.159-165
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• 1990

Ethanol fermentation by Scccharomyces cervisiae was carried out in the cell recycle filter system with a cheap fabric filter having a pore size of 10${\mu}$m. Maximum biomass concentrations up to 85g/1 were obtained, but in practice operational concentrations were between 50 and 80g/1. Ethanol productivity was 42g/1-hr, with an ethanol concentration of 66g/1 and an ethanol yield of over 86%. Continuous operation was possible by applying periodic backflushing. The ethanol fermentation could be carried out without difficulty at a dilution rate up to 0.8h-1 In order to obtain a high cell concentration and ethanol productivity, development of filter module with the larger filtration area is required.

• 한국미생물·생명공학회지
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• 제23권4호
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• pp.479-484
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• 1995

The effect of initial cell concentration on the characteristics of ethanol fermentation was investigated in the batch fermentation of Saccharomyces cerevisiae ATCC 24858. The characteristics were investigated in the range of 60 to 230 g/l of the initial sugar concentrations and 0.5 to 85 g/l of the initial cell concentrations. When the initial cell concentrations were 27 g/l for 60 g/l of the initial sugar and 85 g/l for 230 g/l, the fermentation time required for the complete consumption of the initial sugar was one hour, respectively. The ethanol productivity increased with the initial cell concentration so that, in the case of 100 g/l of initial sugar, the productivity rose up to 55 g/l/hr at 55 g/l of the initial cell concentration. The specific growth rate decreased according to the increase in the initial biomass concentration and finally became zero at around 25 g/l of the cell concentration regardless of the initial sugar concentration. The specific ethanol production rate was constant as 1.02 g/l/hr up to 150 g/l of the initial sugar. However, the rates decreased sharply with the augmentation of concentration of the initial sugar above 160 g/l. The overall ethanol yield represented a constant value, 0.475 g/g irrespective of the initial cell and sugar concentrations. The overall biomass yietd showed a trend to diminish in values with the biomass and ultimately to reach zero more than 25 g/l of the initial cell concentration.

• 한국미생물·생명공학회지
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• 제14권2호
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• pp.199-203
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• 1986

Wood chip을 support로 충전한 관형발효조에 Saccharomyces formosensis 효모용액을 통과시켜 고정화한 관형발효조에서 연속 발효실험을 수행한 결과 wood chip은 support로서 높은 효모 고정화율을 나타내었다. 관형발효조에서 발효실험시 유량 및 농도의 변화시 정상상태에 도달하는데 약 60시간 소요되었고, 정상상태에서 ethanol수율은 0.473-0.483로서 회분식 발효조 경우보다 높은 값을 나타냈다. 정상상태에서 ethanol생산성 (공간체적 기준)은 ethanol농도 61.4-65.7 g/l 범위에서 24.4-19.1g EtOH/$\ell$.hr를 나타내어 다른 고정화법에 의한 것과 비슷하게 높았다. 관형발효조에서 410시간 연속 발효운전시 오염현상이 없었고 효모생존율은 88-93%로 유지되었다.

• 미생물학회지
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• 제27권3호
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• pp.221-224
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• 1989

녹말로부터 에탄올을 직접 생산하는 균주를 개발하고자 amylase 활성이 높은 Aspergillus oryzae와 알콜발효능이 있는 Saccharomyces cerevisiae의 원형질체를 융합하였다. 이들의 융합을 유도하기 위해서 fusogen으로 35% PEG 4000을 사용하였으며, 융합체의 선별을 위한 유전적 지표로는 아미노산 요구성을 사용하였다. 융합률은 $4.6\times 10^{-6}$이었다. 선별된 융합체들은 효모의 형태였으며 amylaseghkf성을 나타내었고, 에탄올을 생사하였다. 그리고 이들 성질 중에서 형태는 후세대에도 안정하게 유지되었으나 녹말로부터의 알콜 생성능은 현저히 감소하였다. 비록 포도당 배지에서의 융합체들의 알콜 생산은 S. cerevisiae의 0.5배에 지나지 않았으나, Prototroph인 S. cerevisiae와는 달리 이들은 녹말로부터 직접 에탄올을 생산할 수 있었다.

• KSBB Journal
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• 제25권2호
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• pp.187-192
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• 2010

S. cerevisiae ATCC 24858을 이용한 ethanol 생산에서, aeration 효과를 ethanol 수율, specific ethanol production rate, ethanol 생산성 측면에서 분석하여, 반복 유가식 공정전략을 설계하였다. Ethanol 수율과 ethanol 생산성은 공기를 0.33 vvm 넣었을 때, 공기를 넣지 않고 배양한 것에 비하여 더 큰 값을 보였고, 24시간 마다 배지를 교체한 배양이 36시간 마다 배지를 교체한 배양 보다 더 큰 값을 보였다. 총 ethanol 생산량 값이 가장 큰 경우는 0.33 vvm의 공기를 넣고, 배지를 24시간마다 완전히 갈아주었을 때이고, 이때 가장 많은 703.8 g의 ethanol이 생산되었다.

• 한국미생물·생명공학회지
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• 제23권3호
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• pp.346-351
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• 1995

To produce ethanol from Jerusalem artichoke powder efficiently, Kluyveromyces marxianus F043 cells were encapsulated in 2% sodium alginate and were cultured in a countinuous reactor to investigate the fermentation properties. Immobilized K. marxianus F043 cells were activated for 48 hours in a fermentor for continuous ethanol production. The culture in a CSTR using a Jerusalem artichoke substrate treated with 2% cellulase showed a decrease in ethanol concentration and an increase in residual saccharide concentration with a increasing dilution rate. Optimum conditions for high ethanol productivity and low residual saccharide output were clarified to be given at a dilution rate of 0.2 h$^{-1}$ and a Jerusalem artichoke medium concentration of 75 g/l. Ethanol productivity of 3.1 g/l-h and saccharide utilization of 62.6% were obtained under the optimum condition. When the fermentation was performed for 3 weeks under these conditions, the effluent medium showed stable ethanol concentrations of 16.3 - 17.9 g/l and viable cells of 6.60-7.16 log cells/ml without contamination. Trace amounts of methyl, n-propyl, iso-butyl, isoamyl alcohols besides ethanol were detected.

• 한국미생물·생명공학회지
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• 제10권1호
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• pp.59-68
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• 1982

• 한국미생물·생명공학회지
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• 제23권6호
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• pp.717-722
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• 1995

Using a flocculating Saccharomyes cerevisiae CA-1, an air-lift reactor equipped with a modified settler was used for ethanol fermentation. The effects of conditions such as aeration rate, initial glucose concentration, and dilution rate were studied using the air-lift reactor. In batch fermentation, optimum aeration rate was 0.5 vvm. In continuous fermentation, aeration rate and initial pH were fixed 0.5 vvm and 4.5, substrate concentration and dillution rate were changed 10-15% and 0.1-1.3. The maximum ethanol productivity was shown to be 20.4 g/l$\cdot $h in 10% glucose and 0.7 h$^{-1}$ dilution rate., and optimum operation condition considering the ethanol productivity and glucose utilization ratio was 0.5 h$^{-1}$ dilution rate in 10% glucose concentration.