• Journal of Microbiology and Biotechnology
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• 제4권1호
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• pp.56-62
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• 1994

A yeast strain, BT001, which can directly ferment D-xylose to ethanol was isolated from forest soils, and then identified as Candida sp. Cultural conditions for the optimum ethanol production, along with the effects of aeration on cell growth and ethanol production were investigated. Aeration stimulated the cell growth and the volumetric rate of ethanol production, but decreased the ethanol yield. Optimum temperature and initial pH for the ethanol production were $33{\circ}^C$ and 6.0, respectively. In a shake flask culture, this strain produced 52.3 g ethanol per liter from 12%(w/v) D-xylose after incubation for 96 hours. Ethanol yield was 0.436 g per g D-xylose consumed. This corresponds to 85.8% of theoretical yield. Also, this yeast strain produced ethanol from D-galactose, D-glucose and D-mannose, but not from L-arabinose and L-rhamnose. Among these sugars, D-glucose was the fastest in being converted to ethanol sugars.

• 한국작물학회지
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• 제57권4호
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• pp.401-408
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• 2012

The grain and agronomic characteristics of Korean barley cultivars were investigated with respect to ethanol yield. Test weight, grain yield, and starch yield showed noticeable variation among the cultivars. Grain yields were higher in covered barley and non-waxy barley. Starch yield was higher in non-waxy barley than waxy barley. Protein, ${\beta}$-glucan, and starch content of tested cultivars ranged in 10.0-12.9%, 4.4-7.5% and 49.7-65.3%, respectively. Naked barley cultivar had higher starch content than covered barley cultivar. However, covered barley had high starch yield because it has higher grain yield than naked barley. Covered barley cultivar had higher husk content, ranging 7.6-14.0%, than that of naked barley cultivar, ranging 5.3-8.0%. Starch content was positively correlated with amylose content, test weight, ethanol yield and negatively correlated with protein, husk, ${\beta}$-glucan content. Ethanol yield per ton was positively correlated with starch content, but negatively correlated with husk content. Ethanol yield per hectare was positively correlated with starch yield, grain yield, grain weight and negatively correlated with protein, test weight. From this research, the important characteristics of barley cultivar as a bioethanol producing material were starch content and grain yield. Optimum barley genotype was non-waxy naked barley that had low protein, ${\beta}$-glucan, husk content, and high starch content and grain yield.

• Journal of Microbiology and Biotechnology
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• 제11권3호
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• pp.384-388
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• 2001

The metabolic pathway synthesis algorithm was applied to estimate the maximum ethanol yield from xylose in a model recombinant Saccharomyces cerevisiae strain containing the genes involved in xylose metabolism. The stoichiometrically independent pathways were identified by constructing a biochemical reaction network for conversion of xylose to ethanol in the recombinant S. cerevisiae. Two independent pathways were obtained in xylose-assimilating recombinant S. cerevisiae as opposed to six independent pathways for conversion of glucose to ethanol. The maximum ethanol yield from xylose was estimated to be 0.46 g/g, which was lower than the known value of 0.51 g/g for glucose-fermenting and wild-type xylose-fermenting yeasts.

• Journal of Ginseng Research
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• 제4권1호
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• pp.1-7
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• 1980

In order to establish effective extracting method of ginseng extracts from fresh ginseng, the yield, chemical composition, physical properties and organoleptic quality of the extracts, which are extracted with various concentrations of ethanol, were investigated. The results are as follows : 1. The yield of the extracts was increased with decreasing the concentration of ethanol as solvent. As in case of water as a solvents, the highest yield was achieved when 23.64% of water was used. The yield were 12.3% and 9.05%, when 70% and 90% of ethanol were used, respectively lively. 2. Crude protein content is the highest level and nitrogen·free extracts content is the lowest at the concentration of 50% ethanol. Lipid was increased linerly while ash was decreased as increment of ethanol concentration. 3. Viscosity and residue of the extracts also decreased in accordance with the increament of ethanol concentration and the transmittance value and pH of extract solutions were almost similar except transmittance value of the water extracts. 4. The extracts extracted with 70% ethanol gave the best result of sensory test. The total sensory test score of each extracts (70%, 90%, 50%, 0% and 30%) were 70, 65, 50, 46 and 41, respectively.

• 한국수소및신에너지학회논문집
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• 제28권6호
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• pp.697-703
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• 2017

This study investigated the high-efficient process for bioethanol from barley by various condition. First, higher concentrations of ethanol could be produced without loss of yield by using reducing water consumption. This is because it could prevent to increase viscosity despite reducing water consumption. Second, the ethanol yield could be improved by using reducing particle size of biomass (increase of enzyme reactive surface). Third, The addition of protease could have a considerable effect on yield of fermentation, which provides nutrients to the yeast. This results showed that bioethanol production would provide efficient ethanol production and lower production costs.

• 한국식품저장유통학회지
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• 제30권5호
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• pp.857-867
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• 2023

본 연구에서는 홍삼과 흑삼의 기능성 성분 추출 극대화를 위해 추출 용액의 ethanol 농도와 추출 온도를 고려하여 추출 수율, 산성다당체 및 ginsenosides의 함량 변화를 반응표면분석법을 통해 모니터링해 보고 적정 추출조건을 찾아보았다. 홍삼 및 흑삼의 가용성 고형분 함량에 대한 모델식의 R²는 각각 0.9679(p<0.01), 0.8545(p<0.1)였다. 홍삼가용성 고형분의 최적 추출조건은 ethanol 농도 1.52%에서 67.27℃로 추출 시 그 함량이 5.29%였으며, 흑삼 가용성 고형분의 최적 추출조건은 ethanol 농도 3.12%에서 66.13℃로 추출 시 그 함량이 6.11%였다. 홍삼 및 흑삼의 산성다당체 함량에 대한 모델식의 R²는 각각 0.9251(p<0.05), 0.88379(p<0.1)였다. 홍삼의 산성다당체 최적 추출조건은 ethanol 농도 4.03%에서 69.61℃로 추출 시 그 함량이 1.86 mg/mL였다. 흑삼의 산성다당체 최적 추출조건은 ethanol 용액 농도 24.67%에서 71.14℃로 추출 시 그 함량이 1.80 mg/mL였다. 홍삼의 ginsenoside Rg₁ 및 Rb₁ 함량에 대한 모델식의 R²는 각각 0.8941(p<0.05), 0.8718(p<0.1)이었다. 홍삼의 ginsenosides 최적 추출조건은 ethanol 농도 79.92%에서 70.62℃로 추출 시 ginsenoside Rg₁ 함량이 0.22 mg/mL였으며, ethanol 농도 79.94%에서 69.46℃에서 ginsenoside Rb₁ 함량이 0.36 mg/mL였다. 흑삼의 ginsenosides 최적 추출조건은 ethanol 농도 75.11%에서 65.21℃로 추출할 경우 ginsenoside Rb₁ 함량이 0.28 mg/mL였으며, ethanol 농도 75.70%에서 65.49℃에서 ginsenoside Rg₃ 함량이 0.31 mg/mL였다. 홍삼 및 흑삼의 산성다당체 수율과 ginsenoside 수율을 모두 만족하는 최적추출조건은 ethanol 농도 35-50%의 범위 내에서 70℃였다.

• KSBB Journal
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• 제9권4호
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• pp.395-399
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• 1994

Pichia stiJitis CBS5776를 이용하여 6탄당과 5 탄당을 함유한 혼합당 배지에서의 에탄올 발효 특성 을 알아 보기 위한 실험을 수행하였다. 탄소원으로 사용된 당 중 에탄올 수율변에셔는 포도당, man­n nose, galactose, xylose 순으로 5탄당보다는 6탄당 이 우수한 기절로 판명되었다. 포도당의 에탄올 수 율이 O.376g ethanol/g glucose로 제 일 높았으며, 다음으로 mannose의 에탄올 수율은 O.326g etha­nnol/g mannose이였다. Spent sulfite liquor와 같은 조성을 가진 혼합당 함유 배지에서 6탄당인 mannose, 포도당이 먼저 이용된 후 galactose와 5탄당인 xylose가 이용됨을 알 수 있었다. Arabinose가 단일 탄소원으로 존재할 경우, 일부가 균체 성장에 이용되였으나 혼합당 배지 에셔는 전혀 이용되지 못하였다. 발효 결과 최대 에 탄올 농도는 $12.2g/\ell$ 이었고, 에탄올 생산 수율은 0.332g ethanol/g sugar이었다.

• Journal of Forest and Environmental Science
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• 제29권2호
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• pp.125-130
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• 2013

An attempt was made on pulp production from the fast growing plant, Acacia hybrid to determine the total yield, screened yield, Kappa number, and fibre morphology of organosolv Acacia hybrid pulp. Uniform-sized chips were taken to undergo pulping in a digester with five different concentrations of ethanol, 50%, 60%, 70%, 80% and 90% (v/v) with 1 M of sodium hydroxide as catalyst. All chips were digested in a temperature-controlled digester with constant amount of water added and temperature of $185^{\circ}C$ with the duration of three hours cooking time and correspond pressure 1.1-1.2 MPa. It was observed that increasing of ethanol concentration has led to pulp yield increment and decreased in the degree of delignification at the same time. This study was aimed to focus on the effect of the varied concentration of organic solvent towards the pulp yield and its relationship with Kappa number and pulp yield.

• KSBB Journal
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• 제10권4호
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• pp.370-373
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• 1995

S.cerevisiae에 의한 에딴올 발효에셔 생성되는 부산물 인 acetic acid, acetaldehyde, glycerol, lactic acid, formic acid가 세포성장과 에탄올 생성에 미치는 영향을 고찰하였다. Acetic acid와 acetaldehyde 를 발효액 내에 투입하였을 때, 세포생장은 저해되 었으나, 에탄올 생성은 증가되었다. 한편, glycerol 과 lactic acid는 세포성장과 에탄올 생산에 거의 영 향이 없었다. Acetic acid와 acetaldehyde는 비성장 속도를 줄임과 동시에 정체기를 늘염으로써 세포성장을 저해하였다. 에단올 수율은 첨가된 acetic acid 와 acetaldehyde 농도에 비례하여 증가하였고, acetic acid $3g/\ell$, acetaldehyde $2g/\ell$ 일 때, 최대가 되었다.

• 한국미생물·생명공학회지
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• 제11권3호
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• pp.181-185
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• 1983

증자하지 않은 Cassava의 생전분의 ethanol 발효생산을 위하여 Aspergilius shirousami 가생산하는 당화효소를 이용하여 단순당화 및 동시당화 발효를 하였다. Cassava 생전분의 당화률은 증자한 것에 비해 30% 정도였으며 10배의 효소를 가하여도 60%밖에 안되었으나. 동시당화-발효에서는 당화율이 크게 증가하여 ethanol 생성량이 증자한 전분에 비해 90% 이상이 되었다.