• Applied Chemistry for Engineering
• /
• v.26 no.4
• /
• pp.511-514
• /
• 2015

A pretreatment process of cellulose decomposition to a monosaccharide plays an important role in the cellulosic ethanol production using the lignocellulosic biomass. In this study, a cellulosic ethanol was produced by using acidic hydrolysis and enzymatic saccharification process from the lignocellulosic biomass such as rice straw, sawdust, copying paper and newspaper. Three different pretreatment processes were compared; the acidic hydrolysis ($100^{\circ}C$, 1 h) using 10~30 wt% of sulfuric acid, the enzymatic saccharification (30 min) using celluclast ($55^{\circ}C$, pH = 5.0), AMG ($60^{\circ}C$, pH = 4.5), and spirizyme ($60^{\circ}C$, pH = 4.2) and also the hybrid process (enzymatic saccharification after acidic hydrolysis). The yield of cellulosic ethanol conversion with those pretreatment processes were obtained as the following order : hybrid process > acidic hydrolysis > enzymatic saccharification. The optimum fermentation time was proven to be two days in this work. The yield of cellulosic ethanol conversion using celluclast after the acidic hydrolysis with 20 wt% sulfuric acid were obtained as the following order : sawdust > rice straw > copying paper > newspaper when conducting enzymatic saccharification.

• Applied Biological Chemistry
• /
• v.32 no.4
• /
• pp.374-377
• /
• 1989

To optimize the enzymatic saccharification of raw-starch, reaction conditions by shaking with glass beads were adapted together with ${\alpha}-amylase$ from Streptomyces sp. 4M-2 and amyloglucosidase from commercial source. When raw-starch was degraded by the ${\alpha}-amylase$ in shaking flask with beads (raw-starch : bead in diam. of 3mm=1 : 5 by weight) at the shaker speed of 300rpm, the saccharification rate of corn and potato starch were increased up to 88% and 69% after 30 hrs of reaction, respectively. Application of the amyloglucosidase in combination with the ${\alpha}-amylase$ enhanced the rate of saccharifcation: 88% of saccharification was obtained in 6 hrs for raw-corn starch under the same reaction conditions as above.

• Korean Chemical Engineering Research
• /
• v.49 no.4
• /
• pp.470-474
• /
• 2011

Rice straw is the main grain straw and is produced in large quantities every year in Korea. Pretreatment of lignocellulosic biomass using soaking process was carried out mild conditions at atmospheric pressure and temperature of $60^{\circ}C$. We found enzymatic hydrolysis condition of pretreated biomass. In case of a rice straw, compared with previous lignocellulosic biomass, we found that hydrolysis time was a shorter than others. Hydrolysis of SAA-treated rice straw has shown conversion rate was higher at $50^{\circ}C$. Hydrolysis was ended between 40~48 hour. Glucose conversion rate was higher when enzyme loading is 65 FPU/ml and 32 CbU/ml. When substrate concentration was 5%(w/v), it was that conversion rate was 83.8% after hydrolysis for 72 hr. In simultaneous saccharification and fermentation(SSF) experiment about SAA-treated rice straw, ethanol productive yield was highest from $40^{\circ}C$. The yield of that time was 33.05% from 48 hour.

• Korean Journal of Food Science and Technology
• /
• v.51 no.1
• /
• pp.18-23
• /
• 2019

An enzymatically saccharified tapioca and hulled barley (TB) raw mixed solution was used to examine alcohol fermentation characteristics. The TB mixture was liquefied with 0.04% ${\alpha}-amylase$ "Spezyme-Fred" and saccharified using an enzyme mixture (GPB), which consisted of glucoamylase (G), protease (P), and ${\beta}-glucanase$ (B). After the TB mixture (7:3, w/w) saccharified for 150 min at $50^{\circ}C$, its glucose content was 12.9% and viscosity was 26 cp. The use of GPB for the saccharification of TB was appropriate because the addition of ${\beta}-glucanase$ increases the glucose yield and decreases the viscosity of the saccharification liquid. The TB ratio was optimized to 7:3 (w/w) on the basis of the lower viscosity and the higher glucose content after saccharification. After TB mixture with 300% (w/w) water content was better condition than others for alcohol fermentation when it was carried out at $30^{\circ}C$. The alcohol and glucose contents of the TB mixture fermented for 72 h were 9.0 and 0.02%, respectively, and the pH and total acidity were 4.3 and 0.3%, respectively.

• Microbiology and Biotechnology Letters
• /
• v.18 no.4
• /
• pp.352-359
• /
• 1990

The synergistic effect of glucoamylase and a -amylase on the hydrolysis of raw corn starch in an agitated bead reaction system was studied by investigating the changes of sugar profiles, the granular structure, particle size distribution, and X-ray diffraction pattern of residual raw corn starch. The enzymatic hydrolysis of raw corn starch was greatly enhanced by synergistic effect of glucoamylase and $\alpha$ -amylase. Even though the sugar profiles were mainly determined by the mixing ratio of glucoamylase and $\alpha$-amylase; raw starch was mainly converted to glucose directly without accumulation of any significant amount of oligosaccharides. The cavity formation and fragmentation phenomena of raw corn starch granule subjected to enzyme reaction were analyzed by means of SEM and the particle size distribution. The X-ray diffraction pattern of raw starch was not changed at the initial stage of reaction but slightly changed at the late stage of hydrolysis, which may be caused by the preferential degradation of amorphous region by enzymatic reaction, not by the destruction of microcrystalline structure of raw corn starch.

• Food Industry
• /
• s.121
• /
• pp.58-69
• /
• 1993

• Korean Journal of Food Science and Technology
• /
• v.6 no.3
• /
• pp.127-132
• /
• 1974

This experiment was carried out to investigate the producing conditions of organic acid and saccarifing amylase in Koji culture by Asp. usamii shirousamii $U_2$. The results were as follows. 1. When the strain $U_2$ was incubated at $30^{\circ}C$, for 3 days in wheat flour and wheat bran media, the organic acid production was maximum. In the case of incubation at $35^{\circ}C$, for 3 days in wheat flour medium and at $35^{\circ}C$, for 2 days in wheat bran medium the activity of saccharifing amylase was highest. 2. When water was added 60% to wheat flour and 50% to wheat bran in the case of 3 days incubation, the organic acid production was superior. Both in wheat flour and wheat bran media, the saccharifing amylase production was most highly, when water was added 90-100%. 3. Comparatively speaking, the organic acid production was better in wheat flour medium than wheat bran medium, but the activity of saccharifing amylase was higher in wheat bran medium. 4. When the sweet potato starch waste and the wheat flour were mixed with same amount, the organic acid and saccharifing amylase production were higher than in simple wheat flour medium. 5. In the medium of sweet potato starch waste the organic acid and saccharifing amylase production were low extremely. 6. In the case of incubation at $30^{\circ}C$, 3 days in wheat flour medium admixed with 60% water, the amount of citric acid in the organic acid formed was about 91%.

• KSBB Journal
• /
• v.21 no.6 s.101
• /
• pp.474-478
• /
• 2006

For the economically feasible production of ethanol, utilization of SFW (saccharified food wastes) as substrate for synchronous saccharification and fermentation (SSF) process was developed in this study. When 200 g of food wastes and 40 mL of enzyme ($amylase activity,\;3.0\;U/m{\ell}$) were reacted, production rate of reducing sugar was $5.84\;g/{\ell}{\cdot}h$, and consumption rate was $-3.88\;g/{\ell}{\cdot}h\;at\;35^{\circ}C$ So suitable condition of SSF was concluded at temperature of $35^{\circ}C$. Also, optimal enzyme concentration of SSF was concluded in $2.0\;U/m{\ell}$, at this condition, the production rate of reducing sugar was $4.80\;g/{\ell}{\cdot}h$ At SSF process, when 50 g of food wastes was supplied in 12 h interval, $64\;g/{\ell}$ of ethanol and 0.45 g-ethanol/g-reducing sugar in yield were obtained in 120 h fermentation. Thus, the technology of high yield of ethanol production using food wastes was confirmed. And semi-continuos SSF system for cutting off cost of enzymatic saccharification was developed in this study.

• Microbiology and Biotechnology Letters
• /
• v.12 no.4
• /
• pp.261-264
• /
• 1984

The optimal condition of the ethanol fermentation from raw cassava starch by simultaneous saccharification - fermentation (SSF) was studied using glucoamylase from Aspergillus sp. and a yeast strain. The rate and yield of ethanol production were optimum at pH 3.6 with shaking. The fine milling treatment was effective for both saccharification and SSF of raw cassava starch. The presaccharification at 6$0^{\circ}C$ for 1 hr before SSF increased the rate and yield of ethanol production, as well. To increase the ethanol concentration after fermentation the substrate concentration could be increased up to 2195 without the problem of viscosity. The use of high concentration ethanol tolerant yeast strains and high substrate concentration produced ethanol higher than 10%(W/V) after fermentation for 5 days.

• KSBB Journal
• /
• v.4 no.2
• /
• pp.87-93
• /
• 1989

To develop high dfficiency-low energy consumption attrition coupled bioreactor for enhanced enzymatic hyerolysis of insoluble biomass, a tumbling drum type bioreactor was installed, and its efficiency was evaluated. The effects of drum structure and poerational conditions were investigated. The optimal saccharification at 3L drum was obtained at 8 baffled drum, drum diameter to baffle height ratio of 1:0.05, 100rpm, and addition of 600g of 3mm glass bead per liter. The consumed power for rolling of drum and energy consumption for half digestion of cellulose were measured, and compared with enhanced rate and yield to predict the economic prospect of the process. The tumbling drum type bioreactor seems to have appropriated structure for industrial scale operation, and further investigation for scale-up need to be conducted.