• Journal of Microbiology and Biotechnology
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• v.9 no.3
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• pp.297-302
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• 1999

Simultaneous saccharification and fermentation (SSF) experiments were carried out with a lignocellulosic biomass. The effects of temperature on enzymatic saccharification and the ethanol fermentation were also investigated. The batch SSF process gave a final ethanol concentration of 10.44 g/l and equivalent glucose yield of 0.55 g/g, which was increased by 67％ or higher over the saccharification at 42℃. The optimal operating condition was found to vary in several parameters, such as the transmembrane pressure, permeation rate, and separation coefficient, related to the SSF combined with membrane system (semi-batch system). When the fermentation was operated in a semi-batch mode, the efficiency of the enzymes and yeast lasted three times longer than in a batch mode.

• Journal of Ginseng Research
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• v.31 no.4
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• pp.191-195
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• 2007

Red ginseng sikhye is one of Korean unique beverages with the addition of effective ingredients of ginseng. Considering economical and mechanical efficiency and quality of sikhye, the optimum conditions for saccharification is to saccharify at 90 degree celsius for 3 hours in the composition of 4% of malt, 20% of steamed rice, and 6% of red ginseng power. The red ginseng sikhye has high soluble solid content over 33% compared with conventional commercial sikhye. On the other hand, ginseng sikhye, which shows low pH, has more or less higher acidity than conventional commercial one. Especially the turbidity of the red ginseng sikhye is much higher than that of commercial sikhye, due to as high amount of rice as 20% compared with 3% in the commercial one. The use of high quantity of rice affected the level of turbidity in red ginseng sikhye. In this study, we wanted to establish optimum conditions for saccharification in manufacturing red ginseng sikhye which contains effective herbal medicinal ingredients maintaining the original taste of traditional sikhye.

• Applied Biological Chemistry
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• v.37 no.6
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• pp.487-491
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• 1994

Relative crystallinities, saccharification efficiency, and diazinon(pesticide) residues of rice and rice hull puffed by hot air puffer were investigated. Crystallinities of rice starch in the puffed rice were decreased as compared to those in cooked rice, and those of rice hull were slightly decreased as compared to those in raw hull. By puffing of glutinous rice, the saccharification efficiency treated with malt amylase was higher than in cooked rice, and hydrolysis ratio of rice hull by cellulase was also increased from 14% to 30% by puffing. The residual contents of diazinon of the puffed rice and rice hull were decreased to 42.7% and 47.6%, respectively. In addition, its decreasing rate in nonglutinous rice were higher than that of glutinous rice.

• Journal of Microbiology and Biotechnology
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• v.29 no.11
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• pp.1760-1768
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• 2019

The use of lignocellulosic biomass such as rice straw can help subsidize the cost of producing value-added chemicals. However, inhibitory compounds, such as phenolics, produced during the pre-treatment of biomass, hamper the saccharification process. Laccase and electrochemical stimuli are both well known to reduce phenolic compounds. Therefore, in this study, we implemented a bioelectrochemical detoxification system (BEDS), a consolidated electrochemical and enzymatic process involving laccase, to enhance the detoxification of phenolics, and thus achieve a higher saccharification efficiency. Saccharification of pretreated rice straw using BEDS at 1.5 V showed 90% phenolic reduction (Ph_r), thereby resulting in a maximum saccharification yield of 85%. In addition, the specific power consumption when using BEDS (2.2 W/Kg Ph_r) was noted to be 24% lower than by the electrochemical process alone (2.89 W/kg Ph_r). To the best of our knowledge, this is the first study to implement BEDS for reduction of phenolic compounds in pretreated biomass.

• Journal of Microbiology and Biotechnology
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• v.30 no.12
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• pp.1912-1918
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• 2020

Hyper-thermal (HT) acid hydrolysis of red seaweed Gelidium amansii was performed using 12% (w/v) slurry and an acid mix concentration of 180 mM at 150℃ for 10 min. Enzymatic saccharification when using a combination of Celluclast 1.5 L and CTec2 at a dose of 16 U/ml led to the production of 12.0 g/l of reducing sugar with an efficiency of enzymatic saccharification of 13.2%. After the enzymatic saccharification, 2,3-butanediol (2,3-BD) fermentation was carried out using an engineered S. cerevisiae strain. The use of HT acid-hydrolyzed medium with 1.9 g/l of 5-hydroxymethylfurfural showed a reduction in the lag time from 48 to 24 h. The 2,3-BD concentration and yield coefficient at 72 h were 14.8 g/l and 0.30, respectively. Therefore, HT acid hydrolysis and the use of the engineered S. cerevisiae strain can enhance the overall 2,3-BD yields from G. amansii seaweed.

• Applied Chemistry for Engineering
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• v.23 no.4
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• pp.399-404
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• 2012

The objective of this study was to investigate the efficient pretreatment method for bioethanol production from rice hull. Ammonia and sodium hydroxide as an alkaline solution and dilute sulfuric acid as an acidic solution were used in a batch reactor under high-temperature and high-pressure conditions. The highest enzymatic saccharification efficiency of 82.8% and ash removal rate of 94.7% were obtained in the dilute sulfuric acid treated sample after the sodium hydroxide solution treatment. The enzymatic saccharification efficiencies and ash removals of pretreated rice hull samples have very similar variation tendency. This means that the maximum obstructive factor for the enzymatic saccharification of rice hull is the ash (silicate) content in biomass. The findings suggest that the combined sodium hydroxide-dilute sulfuric acid treatment system under high-temperature and high-pressure conditions is a promising pretreatment method to enhance the enzymatic saccharification of the silica-rich biomass.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.6
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• pp.609-614
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• 2010

In the present study, bioethanol was produced using batch style reactor from food wastes which has organic characteristics. Pretreatment was required to reduce its particle size and produce fermentable sugar. Two different enzymes such as carbohydrase and gulcoamylase were tested for saccharification of food waste. The efficiency of carbohydrase saccharification (0.63 g/g-TS) has shown higher than glucoamylase saccharification(0.42 g/g-TS). Saccharomyces cerevisiae produced bioethanol via separate hydrolysis & fermentation (SHF) method and simultaneous saccharification fermentation (SSF) method. The production amount of bioethanol was 0.27 g/$L{\cdot}hr$ for SHF and 0.44 g/$L{\cdot}hr$ for SSF.

• Journal of Microbiology and Biotechnology
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• v.23 no.11
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• pp.1577-1585
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• 2013

Bioethanol production from lignocellulose is considered as a sustainable biofuel supply. However, the low cellulose hydrolysis efficiency limits the cellulosic ethanol production. The cellulase is strongly inhibited by the major end product cellobiose, which can be relieved by the addition of ${\beta}$-glucosidase. In this study, three ${\beta}$-glucosidases from different organisms were respectively expressed in Saccharomyces cerevisiae and the ${\beta}$-glucosidase from Saccharomycopsis fibuligera showed the best activity (5.2 U/ml). The recombinant strain with S. fibuligera ${\beta}$-glucosidase could metabolize cellobiose with a specific growth rate similar to the control strain in glucose. This recombinant strain showed higher hydrolysis efficiency in the cellulose simultaneous saccharification and fermentation, when using the Trichoderma reesei cellulase, which is short of the ${\beta}$-glucosidase activity. The final ethanol concentration was 110% (using Avicel) and 89% (using acid-pretreated corncob) higher than the control strain. These results demonstrated the effect of ${\beta}$-glucosidase secretion in the recombinant S. cerevisiae for enhancing cellulosic ethanol conversion.

• KSBB Journal
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• v.29 no.5
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• pp.307-315
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• 2014

Recently seaweed polysaccharides have been extensively studied for alternative energy application. Because their producing cost is high and efficiency low, their industrial applications have been limited. The main component of cell wall of red algae represented by Gelidiales and Gracilariales is agar. Red-algae agar or galactan, consisting of D-galactose and 3, 6-anhydro-L-galactose, is suitable for bio-product application if hydrolyzed to monomer unit. For the hydrolysis of algae, chemical or enzymatic treatment can be used. A chemical process using a strong acid is simple and efficient, but it generates together with target sugar and toxic compounds. In an enzymatic hydrolysis process, target sugar without toxic compounds generation. The objective of this review is to summary the recent data of saccharification by chemical and enzymatic means from red seaweed for especially focused on automobile industry.

• Journal of Energy Engineering
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• v.24 no.3
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• pp.1-5
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• 2015

This study is to investigate the effect of torrefaction on enzymatic hydrolysis of lignocellulosic biomass for bio-ethanol production. As a pretreatment, the torrefaction of lignocellulosic biomass was conducted in temperature of $250{\sim}350^{\circ}C$ in the absence of oxygen. Tween-80, nonionic surfactant, was tested to enhance saccharification efficiency by coping with hydrophobicity resulted from torrefaction. As a result, the glucose production from enzymatic hydrolysis of biomass pretreated by torrefaction was greater than that obtained from the non-pretreated biomass. Sugar conversion was higher when the biomass was saccharified with addition of tween-80. It was found that torrefaction can be applied as a preptreatment for lignocellulosic biomass and tween-80 is needed to enhance its enzyme saccharification.