• Molecules and Cells
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• v.28 no.4
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• pp.369-373
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• 2009

Heterologous secretory expression of endoglucanase E (Clostridium thermocellum) and ${\beta}$-glucosidase 1 (Saccharomycopsis fibuligera) was achieved in Saccharomyces cerevisiae fermentation cultures as an ${\alpha}$-mating factor signal peptide fusion, based on the native enzyme coding sequence. Ethanol production depends on simultaneous saccharification of cellulose to glucose and fermentation of glucose to ethanol by a recombinant yeast strain as a microbial biocatalyst. Recombinant yeast strain expressing endoglucanase and ${\beta}$-glucosidase was able to produce ethanol from ${\beta}$-glucan, CMC and acid swollen cellulose. This indicates that the resultant yeast strain of this study acts efficiently as a whole cell biocatalyst.

• Food Science and Preservation
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• v.15 no.4
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• pp.512-517
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• 2008

Fermentation characteristics of chestnut-added yakju prepared using various proportions of raw materials such as rice koji, rice flour, cornflour koji and cornflour were investigated. The pH of chestnut-added yakju prepared with cornflour koji and saccharified cornflour showed a higher value than that of chestnut-yakju prepared with rice koji and saccharified rice flour. The total acid content of chestnut-added yakju prepared with rice koji and saccharified rice flour was higher than that of chestnut-added yakju prepared using cornflour koji and sacharified cornflour. The reducing of sugar in chestnut-added yakju prepared with saccharified rice flour or saccharified cornflour was rapid at the first brewing stage, decreased dramatically after 2 days, and then decreased slowly after 5 days of fermentation. The value of L and a, the Hunter values, were high in chestnut-added yakju prepared with cornflour koji, and value b was high in chestnut-added yakju with rice koji. The content of iso-amyl alcohol was the highest of seven kinds of fusel oil found in chestnut-added yakju. Ethanol content increased to $17.6{\sim}18.2%$(v/v) after 8 days of fermentation. The content of lactic acid was the highest of all organic acids in the chestnut-added yakju. Sensory test results on chestnut-added yakju prepared with saccharifed corn flour showed that if rice flour is used as a sugar supplement for chestnut, the yakju prepared using koji had better flavor and taste. If cornflour was used in the preparation of chestnut-added yakju, the used of saccharified cornflour offered superior flavor and taste.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.114.2-114.2
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• 2011

Furfural is a versatile derivative. It can be utilized for a building-block of furfuryl alcohol production and a component of fuels or liquid alkanes. But in bio-process, furfural is a critical compound because it inhibits cell growth and metabolism. Furfural could be converted from xylose and usually produced from biomass in which hemicellulose is abundant. In this study, furfural production from miscanthus was performed and utilization of miscanthus residue was consequently conducted. At first, hydrolysis for investigation of miscanthus composition and furfural production was performed using sulfuric acid. Previously, we optimized dilute acid pretreatment condition for miscanthus pretreatment and the condition was found to be about 15 min of reaction time, 1.5% of acid concentration and about $140^{\circ}C$ of temperature and 60% (about 7 g/L) of xylose was solubilized from miscanthus. Using the xylose, furfural production was conducted as second step. Approximately $160{\sim}200^{\circ}C$ of temperature was accompanied with the hydrolysis for pyrolysis of biomass. When the investigated condition; $180^{\circ}C$ of temperature, 20 min of reaction time and 2% of acid concentration was operated for furfural production, furfural productivity was reached to be 77% of theoretical maximum. After reaction, residue of miscanthus was utilized as feedstock of ethanol fermentation. Residue was well washed using water and saccharified using hydrolysis enzymes. Hydrolysate (glucose) from saccharification was utilized for the carbon source of Saccharomyces cervisiae K35.

• Korean Chemical Engineering Research
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• v.54 no.4
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• pp.494-500
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• 2016

In order to remove acetyl group from yellow poplar, deacetylation was performed using sodium hydroxide (NaOH) prior to oxalic acid pretreatment. During the deacetylation ($60^{\circ}C$ for 80 min, 0.8% NaOH), most of the acetyl group were removed from hemicellulose. Simultaneous saccharification and fermentation (SSF) and semi-SSF were carried out based on solid loading (10, 12.5, 15%) of deacetylated biomass and pre-hydrolysis with enzymes (0, 6, 12, 24 h). The highest ethanol was obtained as 26.73 g/L after 120 h when 10% of biomass was used for SSF. It is corresponding to 88.41% of theoretical ethanol yield. At the 12.5% and 15% of biomass loading, the highest ethanol was obtained from 6 h pre-hydrolysis. It was 32.34 g/L and 27.15 g/L, respectively, and corresponding to ethanol yield of 85.58 and 59.87%. In order to remove fermentation inhibitors from hydrolysates, overliming was performed using calcium hydroxide ($Ca(OH)_2$). The highest ethanol was 5.28 g/L after 72 h of fermentation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.637-645
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• 2016

This study was conducted to investigate the characteristics of fermentation and quality of Cheongju prepared by mashing using rice Nuruk inoculated with Aspergillus oryzae. Mashes were prepared by fermentation for 30-50 days using different amounts of fermenting agent, brewing water, milling ratios and fermenting temperatures. Adding fermenting agent at 15% resulted in slow fermentation, but a final alcohol content of 17% (v/v), similar to other samples tested. Addition of higher amounts of Nuruk resulted in increased amounts of citric acid, tartaric acid and malic acid, but low levels of succinic acid. Incomplete fermentation occurred when the ratio of brewing water was low, but the alcohol content (17%) of all samples was similar. When the amount of brewing water was high, the organic acid was levels were high. The speed of saccharification and fermentation was low when fermentation was conducted at $10^{\circ}C$, but the final alcohol content was the highest at this temperature. However, the content of n-propanol, isobutanol, isoamyl alcohol and organic acid was low at low temperature. At this time, the content of citric acid and malic acid was low, but the content of succinic acid was high. A higher milling degree resulted in a lower content of alcohol, organic acid and higher alcohols, with 10% milling resulting in a significantly higher content than the other samples.

• Journal of the Korean Wood Science and Technology
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• v.46 no.1
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• pp.17-28
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• 2018

In this study, catalytic activation using sulfuric acid lignin (SAL), the condensed solid by-product from saccharification process, with potassium hydroxide at $750^{\circ}C$ for 1 h in order to investigate its potential to nanoporous carbon In this study, catalytic activation using sulfuric acid lignin (SAL), the condensed solid by-product from saccharification process, with potassium hydroxide at $750^{\circ}C$ for 1 h in order to investigate its potential to nanoporous carbon material. Comparison study was also conducted by production of activated carbon from coconut shell (CCNS), Pinus, and Avicel, and each activated carbon was characterized by chemical composition, Raman spectroscopy, SEM analysis, and BET analysis. The amount of solid residue after thermogravimetric analysis of biomass samples at the final temperature of $750^{\circ}C$ was SAL > CCNS > Pinus > Avicel, which was the same as the order of activated carbon yields after catalytic activation. Specifically, SAL-derived activated carbon showed the highest value of carbon content (91.0%) and $I_d/I_g$ peak ratio (4.2), indicating that amorphous large aromatic structure layer was formed with high carbon fixation. In addition, the largest changes was observed in SAL with the maximum BET specific surface area and pore volume of $2341m^2/g$ and $1.270cm^3/g$, respectively. Furthermore, the adsorption test for three kinds of organic pollutants (phenol, 2,4-Dichlorophenoxyacetic acid, and carbofuran) were conducted, and an excellent adsorption capacity more than 90 mg/g for all activated carbon was determined using 100 ppm of the standard solution. Therefore, SAL, a condensed structure, can be used not only as a nanoporous carbon material with high specific surface area but also as a biosorbent applied to a carbon filter for remediation of organic pollutants in future.

• Food Science and Preservation
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• v.7 no.2
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• pp.233-239
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• 2000

To proceed mass production and improve its quality, we fermented potatoes using pilot system and investigated the changes in components during fermentation. After liquefaction and saccharification of potatoes by Nuruk(group I), crude enzyme(group II) and glucoamylase(group III), sugar contents in all groups were 18brix equally. However sugar contents in group(II) and group(III) after 24hrs decreased deeply to 7.2 and 8.8 % respectively, after 24hrs. Alcohol content in group(I) increased slowly and was the highest such as 6.8% after 48hrs. Fusel oils in all groups were n-propanol, isobutanol and isoamylalcohol. The major fusel oil in all groups was isoamylalcohol. At the early stage of fermentation, free sugars were glucose, maltose and lactose. Glucose decreased deeply during fermentation and at latter of the fermentation, galactose was detected in all groups. The contents of total free amino acid were 516.57~569.98 mg% in group(I), 193.97~292.11 mg% in group (II) and 186.31~270.53 mg% in group(III). The contents of aspartic acid, serine, glutamic acid, alanine, arginine, and histidine were high in all groups.

• Korean Journal of Food Science and Technology
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• v.45 no.2
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• pp.252-256
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• 2013

We tested the possibility of utilizing Korea domestic wheat (winter wheat variety "keumkangmil") as a source of vinegar production. After saccharification of the whole-wheat flour with wheat malt, the saccharized liquid undergoes alcoholic fermentation, followed by acetic fermentation. Acetic acid bacterium A8, which showed the highest acetic acid production (4.56%) with domestic wheat as substrate, was selected from conventional vinegars. The strain A8 was identified as Acetobacter pasteurianus A8 through phylogenetic study using 16S rDNA sequencing analysis. The optimal condition for the malt enzyme was found to be $15^{\circ}C$ for germination periods of 6 days; its amylase activity was 608.4 U. Acetic acid production from domestic wheat substrate supplemented with 5% ethyl alcohol reached 5.8% after 24 days of static fermentation at $30^{\circ}C$ with a seeding rate of 5%.

• Korean Journal of Microbiology
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• v.5 no.2
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• pp.43-54
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• 1967

The characteristics of enzymic sources and its effective uses concerned with brewing of Yack-Tack Joo which is traditional and popular liquors for all Korean have been studied. Results obtained are as follows; 1)Kock Ja (enrich of fungi and yeast produced in Korean brewery) is found to be weak in its liquifying(600U.) and saccharifying activity(1300U.), so that it is useful to conbine two factors effectively for better brewing. 2) The additional ratio of Kok Ja per materials is seems proper at line of 20 percent for better fermentation and the enzymic preparations inoculated of microorganisms in wheat bran is seems proper at 25 percent line. 3) Adding the enzymic preperation in which the strain Rhyzopus had been inoculated to the experimental mash at 5 percent per material, the rate of fermentation was revealed highest degree than those of else. 4) It is not proper to add a single Bun Kok in fermentation, as it produce much acid in mash during brewing. 5) However, the enzymic preparation composed of Asp usami and Rhyzopus sp. produced less acid in brewing. 6) The increasing of temparature in enzymic samples, temparatures of the mixtured Kuk(Kok Ja and enzymic preparation) are higher than those of single addition at the first stage in pre-fermentation, but there are no differences at the late stage of post-fermentation. 7) Amount of amino acids in the plot of enzymic prepation are found much more than those of single use at late stage of post-fermentation. In the plot of single use of Kock Ja, the amount was the most than else, the proteinase activity is strongest more than else. 8) In the brewing of Korean Tack-Yack-Joo, it is desirable less amount of acidity, more amount of amino acid, stronger liquifaction of starch and vigorous saccharification. Thren it was found that the application of two prepations(Kock Ja and Bun kok) is most effective to get moderate quality in Tack-Yack-Joo brewing.

• KSBB Journal
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• v.5 no.4
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• pp.383-390
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• 1990

Alcoholic distillery waste was utilized as dual purposes to produce citric acid and to reduce the amount of waste to be treated. Enzyme and acid hydrolysis of this waste were studied to suggest effective way of present purpose. Enzymatic hydrolysis of this naked barley alcoholic distillery waste by $\alpha$-and $\beta$-amylase gave glucose as 8g/l concentration at $55^{\circ}C$ for 6 hours, which produced 1g/l citric acid and 5.33g/l mycelial. This waste material hydrolyzed with 25% HCl at $120^{\circ}C$ showed 21.5g/l glucose and produced 1.75g/l citric acid with 4.9g/1 mycelial. The glucose concentration was decreased to 3.44g/l by further 2nd acid hydrolysis because the monosugars were decomposed at prolonged hydrolysis conditions. The addition of 3g/l $NH_4NO_3$ increased the mycelial growth but reduced the amount of citric acid formed. The formation of citric acid was increased at low concentration of manganese ion.