• Journal of the Korean Wood Science and Technology
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• v.47 no.2
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• pp.145-162
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• 2019

This study aimed to increase the sugar and ethanol yield from the mengkuang plant biomass through biological and liquid hot water (LHW) pretreatment and their combination. The results showed that biological pretreatments with 5% inoculum of the fungus Trametes versicolor resulted in the highest alpha cellulose content incubated for 30 days, and 10% inoculum resulted in the lowest lignin content. LHW pretreatment decreased the hemicellulose content of pulps from 10.17% to 9.99%. T. versicolor altered the structure of the mengkuang pulp by degrading the lignin and lignocellulose matrix. The resulting delignification and cellulose degradation facilitate the hydrolysis of cellulose into sugars. The alpha cellulose content after biological-LHW pretreatment was higher (78.99%) compared to LHW-biological pretreatment (76.85%). Scanning electron microscopy analysis showed that biological-LHW combinated treatment degrades the cell wall structures. The ethanol yield for biological-LHW pretreated sample was observed 43.86% (13.11 g/L ethanol by weight of the substrate, which is much higher than that of LHW-biological pretreatment (34.02%; 9.097 g/L). The highest reducing sugar content about 45.10% was observed with a resulting ethanol content of 15.5 g/L at LHW pretreatment temperature of $180^{\circ}C$ for 30 min.

• KSBB Journal
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• v.11 no.3
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• pp.367-373
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• 1996

The growth characteristics of Rhodotorula sp. Y-55 were examined on minimal medium containing ethanol, acetic acid or acetadehyde as a sole carbon source by batch culture. The increased concentration of substrate reduced overall growth yield and prolonged lag time. The specific growth rate of the yeast was changed, depending upon the initial concentrations of ethanol and acetaldehyde during the exponential period, but was constant on acetic acid without regard to the initial substrate concentrations, giving a value of 0.l07h-1. The highest ${\mu}$ value was obtained on ethanol and acetadehyde substrates and the respective values were 0.270 at 20g/L and 0.041h-1 at 0.2g/L. The maximum overall growth yields were appeared to be 32.6% for ethanol of 10g/L, 25.6% for acetic acid of 20g/L, and 45% for acetaldehyde of 0.2g/L. The respective cellular contents of crude protein and nucleic acids were determined to be 41.5 and 4.9wt% on ethanol and 40.2 and 4.7wt% at the concentration revealing maximal growth yield.

• Journal of Life Science
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• v.29 no.1
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• pp.135-145
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• 2019

Zymomonas mobilis has been recognized as a potential industrial ethanologen for many decades due to its outstanding fermentation characteristics, including high ethanol tolerance, fast sugar uptake rate, and high theoretical ethanol yield. With the emergence of the postgenomic era and the recent announcement of DuPont's world largest cellulosic ethanol production process, research on this bacterium has become even more important to harness successful application not only for use in the bioethanol process but also in other biochemical processes, which can be included in bio-refinery. As an important industrial microorganism, Z. mobilis will likely be exposed to various stressful environments, such as toxic chemicals, including the end-product ethanol and fermentative inhibitory compounds (e.g., furan derivatives, organic acids, and lignin derivatives in pretreatment steps), as well as physical stresses, such as high temperature during large-scale ethanol fermentation. This review focuses on recent information related to the industrial robustness of this bacterium and strain development to improve the ethanol yield and productivity in the lignocellulosic ethanol process. Although several excellent review articles on the strain development of this bacterium have been published, this review aims to fill gaps in the literature by highlighting recent advances in physiological understanding of this bacterium that may aid strain developments and improve the ethanol productivity for lignocellulosic biomass.

• Journal of Ginseng Research
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• v.15 no.3
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• pp.192-196
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• 1991

As a part of studios on the Quality control of index components in crude drug preparations, extraction yields of ginseng saponins from crude drug extracts were identified by TLC and quantified by HPLC. So-Shi-Ho-Tang(小柴胡湯), Sa-Kun-Ja-Tang(四君子湯), Yook-Kun-Ja-Tang(六君子湯) and In-sam-Tang(人蔘湯) were extracted with water, 30%-ethanol, 50%-ethanol, 80%-ethanol and absolute ethanol to analyze ginseng saponins in the crude drug extracts prepared with various concentrations of ethanol. Ginseng saponins were extracted considerably more from the extracts with higher concentrations of ethanol than those with water or lower concentrations of ethanol. Extraction yields of ginseng-side-Rb$_1$, -Rb$_2$ and -R$_c$ from four crude drug preparations were the lowest as 4.9~45.9%, 5.0~40.1, and 6.3~43.7% in water extract and the highest as 29.5~62.6%, 26.7~61.4% and 31.4~62.0% in absolute ethanol extract, compared with those of 80%-methanol extracts.

• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.588-596
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• 1992

The fermentation characteristics of ethanol production by the use of immobilized Zymomonas mobilis KCTC 1534 cells were investigated in terms of formation factors such as substrate and product concentration. In batch fermentation, the maximum values of specific ethanol productivity, specific substrate uptake rate, ethanol yield, and glucose conversion rate were $29.14g/{\ell}{\cdot}h$, $60.24g/{\ell}{\cdot}h$, 0.48g/g, and 98.4%, respectively, with 17% glucose medium, and its ethanol productivity was $2.91g/{\ell}{\cdot}h$ in the case of 25 hour fermentation time. Repeated batch fermentation was possible for 30 days with 2.24-$2.94g/{\ell}{\cdot}h$ ethanol productivity. In semicontinuous fermentation, the maximum ethanol productivity was shown to be $15.7g/{\ell}{\cdot}h$ at $0.36h^{-1}$ effective dilution rate with 17% glucose concentration. In this case, ethanol yield coefficient and glucose conversion rate were 0.39 g/g, 64.7%, respectively.

• Korean Chemical Engineering Research
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• v.46 no.5
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• pp.858-862
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• 2008

The Simultaneous Saccharification and Fermentation(SSF) of ethanol production from potato starch studied with respect to growth pH, temperature, substrate concentration. The glucoamylase and Saccharomyceses cerevisiae have a capacity to carry out a single stage SSF process for ethanol production. The characteristics, termed as starch hydrolysis, accumulation of glucose, ethanol production and biomass formation, were affected with variation in pH, temperature and starch concentration. The maximum ethanol concentration of 12.9g/l was obtained using a starch concentration 30g/l, which represent an ethanol yield of 86%. The optimum conditions for the maximum ethanol yield were found to be a temperature of 38, pH of 4.0 and fermentation time of 18hr. Thus by using the control composite design, it is possible to determine the accurate values of the fermentation parameters where maximum production of ethanol occurs.

• KSBB Journal
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• v.23 no.6
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• pp.504-508
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• 2008

The objectives of this study were to develope the economical process for bioethanol production from domestic triticale and investigate optimal fermentation conditions such as temperature, time, and enzyme concentration used to pre-treatment process. Triticale mash, containing 148 g of total sugar per 1 L of mash, was fermented with Saccharomyces cerevisiae CHY1011 at $33^{\circ}C$. Fermentation of mash supplemented with enzyme was completed within 48-60 hours, and the ethanol yield was 410.9 L/tonne of dry base. On the other hand, fermentation of mash without enzyme addition was completed within 36-48 hours, but the ethanol yield was 342.2 L/tonne of dry base. For optimal bioethanol production from triticale, viscosity reduction enzyme was added in the pre-treatment process, and the fermentation rate of triticale was 92.0-94.2%. In addition, the results showed that bioethanol production of triticale by low-temperature pre-treatment would provide higher ethanol production efficiency and lower operating costs.

• Journal of Microbiology and Biotechnology
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• v.23 no.9
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• pp.1244-1252
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• 2013

Sugar beet pulp is an abundant industrial waste material that holds a great potential for bioethanol production owing to its high content of cellulose, hemicelluloses, and pectin. Its structural and chemical robustness limits the yield of fermentable sugars obtained by hydrolyzation and represents the main bottleneck for bioethanol production. Physical (ultrasound and thermal) pretreatment methods were tested and combined with enzymatic hydrolysis by cellulase and pectinase to evaluate the most efficient strategy. The optimized hydrolysis process was combined with a fermentation step using a Saccharomyces cerevisiae strain for ethanol production in a single-tank bioreactor. Optimal sugar beet pulp conversion was achieved at a concentration of 60 g/l (39% of dry weight) and a bioreactor stirrer speed of 960 rpm. The maximum ethanol yield was 0.1 g ethanol/g of dry weight (0.25 g ethanol/g total sugar content), the efficiency of ethanol production was 49%, and the productivity of the bioprocess was 0.29 $g/l{\cdot}h$, respectively.

• Food Science and Biotechnology
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• v.16 no.2
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• pp.299-305
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• 2007

Response surface methodology was employed to optimize extraction conditions for finding the maximal functional properties of Pleurotus eryngii. Based on central composite design, the study plan was established with variations of microwave power (30-150 W), ethanol concentration (0-99.9%), and extraction time (1-9 min). Regression analysis was applied to obtain a mathematical model. A maximal yield of 47.86% was obtained when the microwave power, ethanol concentration, and extraction time were set at 122.7 W, 42.14%, and 8.3 min, respectively. A maximized electron donating ability of 93.32% was found under the following conditions: a microwave power of 144.19 W, an ethanol concentration of 49.52%, and an extraction time of 6.7 min. When the microwave power, ethanol concentration, and extraction time were set at 125.43 W, 40.54%, and 8.1 min, respectively, the maximum nitrite-scavenging ability was 80.47%. The optimum ranges of the extraction conditions, superimposed by the response surface methodology, could predicate a microwave power of 110-150 W, ethanol concentration of 0-45%, and extraction time of 7-9 min.

• Korean Journal of Medicinal Crop Science
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• v.18 no.4
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• pp.244-247
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• 2010

It's crucial to control Alternaria blight and Anthracnose emerging mostly on ginseng leaves during the rainy season to increase the organic ginseng products. The purpose of this study is to investigate the efficay of lime-brodeaux spray on the ginseng leaves and evaluate the growth and yield of the ginseng, and the contents of ginsenoside and 70% ethanol extracts from 3-year-old ginseng variety, Cheonpoong. Lime-bordeaux sprayings were conducted in the ratio of 6-6 in June, 8-8 from July to September every 15 days. After June 10, the spraying have no effects on the growth leaf and stem, and there was no significant increase in chlorophyll contents. The ratio of intact leaf and root were distinctly increased because Alternaria blight and Anthracnose were decreased by spraying lime-bordeaux mixture. Root weight per plant and root yield were increased by 15%, and 62% in 3-year old ginseng, respectively, because the ratio of intact leaf and root were higher by using lime-bordeaux mixture. Furthermore, spraying of lime-bordeaux mixture is prone to increase the ratio of rusty root in ginseng. Spraying of lime-bordeaux mixture decreased both of the contents of ginsenoside and 70% ethanol extract by 13.7%, and 15.2% in 3-year-old ginseng, respectively.