• Korean Journal of Food Science and Technology
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• v.48 no.1
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• pp.48-53
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• 2016

The objective of this study was to evaluate the accuracy and efficiency of different methods used for the fermentable sugar assay in the production of Makgeolli sul-dut. In the initial stage of fermentation, Ipguk treatment produced a higher alcohol content compared to the Nuruk treatment. However, the alcohol content was not significantly different between the two starters at the final stage of fermentation. Acidity in the Ipguk treatment was higher than that of Nuruk throughout the fermentation period. After analyzing the fermentable sugars using dinitrosalicylic acid (DNS), Fehling's method, refractometer, glucose kit, and high performance liquid chromatography (HPLC), it was confirmed that the HPLC method was the most accurate for fermentable sugar quantification. In both types of starters, DNS and Fehling's methods showed results comparable to HPLC in terms of fermentable sugar content, while the glucose kit and refractometer analyses showed relatively large discrepancies, indicating that the Fehling's method could also be effective for the analysis of fermentable sugars in the manufacture of Makgeolli.

• Journal of Mushroom
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• v.20 no.1
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• pp.1-6
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• 2022

A novel brown rot fungus Phaeolus schweinitzii IUM 5048 was firstly used for ethanol production. It was found that this fungus produced ethanol with various sugars, such as glucose, mannose, galactose and cellobiose at 0.28, 0.22, 0.06, and 0.22 g of ethanol per g of sugar consumed, respectively. This fungus showed relatively good ethanol production from xylose at 0.23 g of ethanol per g of sugar consumed. However, the ethanol conversion rate of arabinose was relatively low (at 0.08 g of ethanol per g sugar). P. schweinitzii was capable of producing ethanol directly from rice straw and corn stalks at 0.11 g and 0.13 g of ethanol per g of substrates, respectively, when the fungus was cultured in a basal medium supplemented with 20 g/L rice straw or corn stalks. These results suggest that P. schweinitzii can hydrolyze cellulose or hemicellulose to fermentable sugars and convert them to ethanol simultaneously under oxygen limited condition.

• Journal of Forest and Environmental Science
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• v.27 no.3
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• pp.183-194
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• 2011

This study reviewed on the research trend of sources and utilization of the byproducts(Lignin) from bioethanol production process with lignocellulosic biomass such as wood, agri-processing by-products(corn fiber, sugarcane bagasse etc.) and energy crops(switch grass, poplar, Miscanthus etc.). During biochemical conversion process, only Cellulose and hemicellulosic fractions are converted into fermentable sugar, but lignin which represents the third largest fraction of lignocellulosic biomass is not convertible into fermentable sugars. It is therefore extremely important to recover and convert biomass-derived Lignin into high-value products to maintain economic competitiveness of cellulosic ethanol processes. It was introduced that lignin types and characteristics were different from various isolation methods and biomass sources. Also utilization and potentiality for market of those were discussed.

• Korean Journal of Weed Science
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• v.32 no.2
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• pp.85-97
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• 2012

To investigate the usefulness of freshwater alga Water-net (Hydrodictyon reticulatum, HR) as resources for production of fermentable sugars, the easiness of enzymatic saccharification was evaluated at first. When 6 plant materials (HR, Spirulina, Chlorella, Scenedesmus, Cladophora, Corn stover) were enzymatically hydrolyzed with 2% solid loading at the same condition, HR showed the highest ratio of saccharification based on glucose production. No milled HR was also completely saccharified at the amounts of optimal enzyme mixture. Glucose yield was not changed though the citrate buffer strength for saccharification was decreased from 0.1 M to 0.1 mM. Only about 10% yield reduction was observed compared to that of $120^{\circ}C$ treatment when HR was enzymatically hydrolyzed at room temperature. The saccharification was normally occurred at $37^{\circ}C$ and pH 6.5 which is general growth condition of fermentable microrganisms, suggesting that HR have a biomass characteristics applicable for the simultaneous saccharification and fermentation. The saccharification was occurred by more than 70~80% of one of the best condition although the supplied enzyme amounts was reduced to 1/10 volume. And the glucose yield by enzymatic hydrolysis was not decreased by 10% HR solid loading and began to decrease at more than 15% solid contents. Above these results show that HR is an interesting algal biomass which is relatively easy to be saccharified by hydrolyzing enzymes. In addition, HR is a flilamentous alga and very easy to be collected. Therefore, HR seems to be an useful and valuable resources in the economical production of fermentable sugars for manufacture of bio-chemical products.

• Korean Journal of Food Science and Technology
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• v.24 no.2
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• pp.107-110
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• 1992

In order to study the prediction of shelf-life and the relation between the initial reducing sugar content (So) and the fermentation period (T) to produce 0.75% acid in kimchi, kimchis were prepared with Chinese cabbage from which fermentable sugars were removed by 0%, 30%, 50%, 74. In kimchis with 2.3%, 0.97%, 0.60%: initial reducing sugar content, fermentation periods to produce 0.75% acid took 2, 7, 12 days, respectively. This relation can be expressed as the following equation; T= -16.82 LogSo+7.66. Kimchi with cabbage removed by about 80% fermentable sugar showed out about 0.8% total acidity during 30 days's storage at $25^{\circ}C$.

• Proceedings of the Korean Society of Crop Science Conference
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• 2018.10a
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• pp.204-204
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• 2018

• Journal of the Korean Wood Science and Technology
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• v.40 no.2
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• pp.123-132
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• 2012

Pre-pulping extracts were found to contain a dilute amount of xylo-oligosaccharides and acetic acid as the major components, and many minor components including other organic acids, lignin-derived phenolics, and sugar degradation products. Once separated from the pulp, a secondary hydrolysis step was required to hydrolyze oligomeric hemicellulose sugars into monomeric sugars before fermentation. The following study detailed the extent of hemicellulose recovery by pre-pulping using hot water extraction and characterized the hydrolysis of the extract with respect to comparing acid and enzymatic hydrolysis. The secondaryhydrolysis of hot water extracts made at an H-Factor of 800 was tested for a variety of acid and enzyme loading levels using the sulfuric acid and xylanases. The maximum fermentable sugar yield from acid and enzyme hydrolysis of the extract was 18.7 g/${\ell}$ and 17.7 g/${\ell}$ representing 84.6% and 80.1% of the maximum possible yield, respectively.

• Carbon letters
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• v.17 no.1
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• pp.1-10
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• 2016

Lignocellulosic biomass conversion to biofuels such as ethanol and other value-added bio-products including activated carbons has attracted much attention. The development of an efficient, cost-effective, and eco-friendly pretreatment process is a major challenge in lignocellulosic biomass to biofuel conversion. Although several modern pretreatment technologies have been introduced, few promising technologies have been reported. Microwave irradiation or microwave-assisted methods (physical and chemical) for pretreatment (disintegration) of biomass have been gaining popularity over the last few years owing to their high heating efficiency, lower energy requirements, and easy operation. Acid and alkali pretreatments assisted by microwave heating meanwhile have been widely used for different types of lignocellulosic biomass conversion. Additional advantages of microwave-based pretreatments include faster treatment time, selective processing, instantaneous control, and acceleration of the reaction rate. The present review provides insights into the current research and advantages of using microwave-assisted pretreatment technologies for the conversion of lignocellulosic biomass to fermentable sugars in the process of cellulosic ethanol production.

• KSBB Journal
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• v.26 no.4
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• pp.317-322
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• 2011

Ulva pertusa is one of the worst pollutant like a waste vinyl after agriculture and caused bad smell at seashore in Jejudo and south area of korean peninsular. For favorable environmental utilization of Ulva pertusa, it could be applied for ethanol production with its acid hydrolysate. The components of hydrolysate included fermentable sugar of glucose, xylose, mannose, galactose, and higher amounts of unfermentable rhamnose. Fermentable sugars were converted to ethanol with S. cerevisiae, also xylose to ethanol with P. stipitis, their maximun ethanol production at optimum conditions were 462 ${\mu}g$/mL and 475 ${\mu}g$/mL, respectively. While, rhamnose cannot be changed to ethanol with S. cerevisiae or P. stipitis, alone. Combination of S. cerevisiae and P. stipitis can convert rhamnose to ethanol, because P.stipitis degradaded rhamnose to pyruvate, and then S. cerevisiae convert to ethanol, at optimum conditions, ethanol reached to 782 ${\mu}g$/mL (30.24%) that is higher than that of 2 strain alone from 500 mg of dried Ulva pertusa contained 2586.45 ${\mu}g$/mL of reduced sugars. Ulva pertusa can be utilized for renewal energy insted of environmenatal enemy.

• KSBB Journal
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• v.27 no.3
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• pp.137-144
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• 2012

Among various pretreatment processes for bioethanol production, extrusion pretreatment, one of cheap and simple process was investigated to efficiently produce fermentable sugars from micro alga, Chlorella sp. The biomass was pretreated in a single screw extruder at five different barrel temperatures of 45, 50, 55, 60 and $65^{\circ}C$, respectively with five screw rotation speed of 10, 50, 100, 150 and 200 rpm. The pretreated biomass was reacted with two different hydrolyzing enzymes of cellulase and amyloglucosidase since the biomass contained different types of carbohydrates, compared to cellulose of agricultural by-products such wheat and corn stovers, etc. In general, higher glucose conversion yield was obtained as 13.24 (%, w/w) at $55^{\circ}C$ of barrel temperature and 100 rpm of screw speed conditions. In treating 5 FPU/glucan of cellulase and 150 Unit/mL of amyloglucosidase, ca. 64% of cellulose and 40% of polysaccharides in the micro alga were converted into glucose, which was higher yields than those from other reported data without applying an extrusion process. 84% of the fermentable sugars obtained from the hyrolyzing processes were fermented into ethanol in considering 50% of theoretical maximum fermentation yield of the yeast. These results implied that high speed extrusion could be suitable as a pretreatment process for the production of bioethanol from Chlorella sp.