• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.3
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• pp.11-17
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• 2015

In acid hydrolysis process of biomass saccharification. neutralization of acid hydrolyzate is essential step, which resulted in dissolved cations in glucose solution. Impact of cations to Kluyveromyces marxianus in glucose solution was investigated focused on ethanol fermentation. Either potassium or sodium cations decreased the ethanol fermentation and glucose to ethanol conversion. Glucose consumption by K. marxianus was delayed by increasing potassium cation concentration as completely consumed within 12 h in potassium cation 0.46 mol and 0.92 mol but within 24 h in potassium cation 1.38 mol. Also, ethanol fermentation process was slowed down with increasing concentration of the potassium sulfate. Fermentation of glucose solution to ethanol was more inhibited by sodium cation than potassium cation in glucose solution. Glucose was completely consumed within 24 h in sodium cation 0.95 mol. but at 1.90 mol or 2.84 mol in sodium cation could not finish the fermentation within 48 hour. Ethanol concentration was 22.26 g/L at low sodium cation in glucose solution with complete fermentation within 24 h. With increasing sodium cation in glucose solution, final ethanol concentration was reached at 14.10 g/L (sodium cation con) and 0.21 g/L (sodium cation con), which meant delaying of fermentation by sodium cations.

• The Korean Journal of Mycology
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• v.40 no.4
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• pp.187-190
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• 2012

Various koji were prepared by fungi isolated from traditional nuruk and their quality characteristics were investigated. Acidity and saccharification power of their koji were ranged in 5.0~6.8 and 128sp~241sp. Nine fungi which were showed good quality and sensory evaluation were identified by analysis of their nucleotide sequences with PCR-amplified 18S rDNA internal transcribed spacer-1(ITS-1) and ITS-4 genes. Among them, six strains were identified as Aspergillus oryzae and the other strains were identified as Mycocladus corymbiferus, Rhizo-pus oryzae, Lichtheimia corymbifera.

• KSBB Journal
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• v.31 no.1
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• pp.79-84
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• 2016

Biofuel has been considered as promising renewable energy to solve various problems that result from increasing usage of fossil fuels since the early 20th century. In terms of chemical and physical properties as fuel, biobutanol has more merits than bioethanol. It could replace gasoline for transportation and industrial demand is increasing significantly. Production of butanol can be achieved by chemical synthesis or by microbial fermentation. The water hyacinth, an aquatic macrophyte, originated from tropical South America but is currently distributed all over the world. Water hyacinth has excellent water purification capacity and it can be utilized as animal feed, organic fertilizer, and biomass feedstock. However, it can cause problems in the rivers and lakes due to its rapid growth and dense mats formation. In this study, the potential of water hyacinth was evaluated as a lignocellulosic biomass feedstock in biobutanol fermentation by using Clostridium beijerinckii. Water hyacinth was converted to water hyacinth hydrolysate medium through pretreatment and saccharification. It was found that productivity of water hyacinth hydrolysate medium on biobutanol production was comparable to general medium.

• Microbiology and Biotechnology Letters
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• v.30 no.1
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• pp.98-102
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• 2002

Lignocellulosic wastes available in abundance can be excellent substrates for the production of cellulase. Different types of substrates and various pretreatments were used to improve the production of cellulase. The steam-exploded wood chip gave the highest activities of FPase (0.84 IU/mL) and CMCase (6.5 IU/mL) in the shake-flask culture. In 30 L bioreactor the steam-exploded wood chip and residue after saccharification gave the FPase activity (0.72 IU/mL) and the CMCase activity (6.3 IU/mL), respectively, similar those obtained in lactose.

• Journal of Microbiology and Biotechnology
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• v.18 no.7
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• pp.1335-1341
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• 2008

The cell wall material from fruiting bodies of Laetporus sulphureus has been suggested as a new alternative to mutan for the mutanase induction in Trichoderma harzianum. Structural analyses revealed that the cell wall fraction from this polypore fungus contained 56.3% of (1$\rightarrow$3)-linked $\alpha$-glucans. When the strain T. harzianum F-340 was grown on a cell wall preparation from L. sulphureus, the maximal enzyme productivity obtained after 3 days of cultivation was 0.71 U/ml. This yield was about 1.8-fold higher than that achieved on mutan, known so far as the best, but expensive and inaccessible, inducer of mutanase production. Cell-wall-induced mutanase showed a high hydrolytic potential in reaction with a dextranase-pretreated mutan, where maximal degrees of saccharification and solubilization of this biopolymer (80% and 100%, respectively) were reached in 3 h at 45$^{\circ}C$. The mutanase preparation was also effective in degradation of streptococcal mutan and its removal from oral biofilms, especially in a mixture with dextranase.

• Microbiology and Biotechnology Letters
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• v.3 no.3
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• pp.135-140
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• 1975

For the purpose of producing single cell protein out of an agricultural waste, chestnut-bur was hydrolyzed with 4％ H$_2$SO$_4$, solution for 30 min under the steam pressure of 1.5kg/$\textrm{cm}^2$, and 21％ saccharification of the original carbon source was obtained. When Candida tropicalis was grown in the hydrolyzate the cell yield remained only 21％ of the original sugar suggesting a necessity of further treatments.

• Microbiology and Biotechnology Letters
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• v.3 no.3
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• pp.141-146
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• 1975

The pre-hydrolyzed residue of Chestnut-bur (1) was treated with 74％ H$_2$SO$_4$, solution at 3$0^{\circ}C$ for 40minutes. Then the solution was diluted to 5％ with distilled water and kept for another 40 minutes under steam pressure of 1.5kg/㎤ to complete the post-hydrolzation. In the resulting hydrolyzate, which showed 49.3％ in saccharification rate, Candida utilis was grown and found that 62.5％ of the reducing sugar had been converted to the yeast cells.

• Journal of Microbiology and Biotechnology
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• v.29 no.6
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• pp.905-912
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• 2019

Bioethanol has attracted much attention in recent decades as a sustainable and environmentally friendly alternative energy source. In this study, we compared the production of bioethanol by Candida molischiana and Saccharomyces cerevisiae at different initial concentrations of cellobiose and glucose. The results showed that C. molischiana can utilize both glucose and cellobiose, whereas S. cerevisiae can only utilize glucose. The ethanol yields were 43-51% from different initial concentrations of carbon source. In addition, different concentrations of microcrystalline cellulose (Avicel) were directly converted to ethanol by a combination of Trichoderma reesei and two yeasts. Cellulose was first hydrolyzed by a fully enzymatic saccharification process using T. reesei cellulases, and the reducing sugars and glucose produced during the process were further used as carbon source for bioethanol production by C. molischiana or S. cerevisiae. Sequential culture of T. reesei and two yeasts revealed that C. molischiana was more efficient for bioconversion of sugars to ethanol than S. cerevisiae. When 20 g/l Avicel was used as a carbon source, the maximum reducing sugar, glucose, and ethanol yields were 42%, 26%, and 20%, respectively. The maximum concentrations of reducing sugar, glucose, and ethanol were 10.9, 8.57, and 5.95 g/l, respectively, at 120 h by the combination of T. reesei and C. molischiana from 50 g/l Avicel.

• Applied Chemistry for Engineering
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• v.20 no.3
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• pp.290-295
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• 2009

Red-algae agar, consisting of D-galactose and 3, 6-anhydro-L-galactose, is usable for bio-ethanol production if hydrolyzed to monomer unit. The objective of this study is to produce bio-ethanol from agar using the heat and acid-treatment. Bio-ethanol was produced by Saccharomyces cerevisiae KCCM1129 strains using agar-pretreatment. The optimal condition for reducing sugar conversion by agar was found to be 15 min reaction at a HCl concentration of 0.1 N and $120^{\circ}C$. The optimum concentration for maximum cell growth was 0.1 N NaCl (17.88 g/L). Over 0.1 N NaCl, the cell growth decreased to 6.78~10.76 g/L. At 16% agar concentration, the ethanol production obtained by optimum pretreatment was found to be 10.16 g/L.

• Journal of Korean Society of Forest Science
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• v.99 no.5
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• pp.744-749
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• 2010

Enzymatic hydrolysate from non pre-treated biomass of yellow poplar (Liriodendron tulipifera) was prepared and used as resource for bioethanol production. Fresh branch (1 year old) of yellow poplar biomass was found to be a good resource for achieving high saccharification yields and bioethanol production. Chemical composition of yellow poplar varied significantly depending upon age of tree. Cellulose content in fresh branch and log (12 years old) of yellow poplar was 44.7 and 46.7% respectively. Enzymatic hydrolysis of raw biomass was carried out with commercial enzymes. Fresh branch of yellow poplar hydrolyzed more easily than log of yellow poplar tree. After 72 h of enzyme treatment the glucose concentration from Fresh branch of yellow poplar was 1.46 g/L and for the same treatment period log of yellow poplar produced 1.23 g/L of glucose. Saccharomyces cerevisiae KCTC 7296 fermented the enzyme hydrolysate to ethanol, however ethanol production was similar (~1.4 g/L) from both fresh branch and log yellow poplar hydrolysates after 96 h.