• 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.

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.40-47
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• 2005

Modeling and simulation for simultaneous saccharification and fermentation (SSF) process in bioconversion of paper mill sludge to lactic acid was carried out. The SSF process combined the enzymatic hydrolysis of paper mill sludge into glucose and the fermentation of glucose into lactic acid in one reactor. A mathematical modeling for cellulose hydrolysis was developed, based on the proposed mechanism of cellulase adsorption deactivation. Another model for simple lactic acid fermentation was also made. A whole mathematical model for SSF was developed by combining the above two models for cellulose hydrolysis and lactic acid fermentation. The characteristics of the SSF process were investigated using the mathematical model.

• Journal of Microbiology and Biotechnology
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• v.24 no.5
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• pp.629-638
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• 2014

This study describes an alternative mixed culture fermentation technology to anaerobically convert lignocellulosic biomass into butyric acid, a valuable product with wide application, without supplementary cellulolytic enzymes. Rice straw was soaked in 1% NaOH solution to increase digestibility. Among the tested pretreatment conditions, soaking rice straw at $50^{\circ}C$ for 72 h removed ~66% of the lignin, but retained ~84% of the cellulose and ~71% of the hemicellulose. By using an undefined cellulose-degrading butyrate-producing microbial community as butyric acid producer in batch fermentation, about 6 g/l of butyric acid was produced from the pretreated rice straw, which accounted for ~76% of the total volatile fatty acids. In the repeated-batch operation, the butyric acid production declined batch by batch, which was most possibly caused by the shift of microbial community structure monitored by denaturing gradient gel electrophoresis. In this study, batch operation was observed to be more suitable for butyric acid production.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.938-945
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• 2005

For elucidating excessive growth of biofilm that subsequently leads to the clogging problem in a small town's sewer lines of Wisconsin, the FISH method was employed. At the beginning of the simulated experiments, ${\beta}$-subclass proteobacteria prevailed in runs fed with industrial wastewater, while ${\gamma}$-subclass proteobacteria dominated in runs with domestic wastewater. However, the bacterial community structure changed significantly over six weeks; Cytophaga-Flavobacterium (CF)­group bacteria dominated in most runs fed with the small town's wastewater regardless of their source, while CF-group decreased strongly in run fed with domestic sewage from another city (Madison). It was also microscopically confirmed that most of those clogging materials was toilet tissue, which in turn may lead to vigorous growth of cellulose-degrading CF-group bacteria. This dominant presence of CF-group bacteria in the small town's sewer indicates that the main constituent of biofilm, toilet tissue (cellulose) in sewage, might have induced the unique pattern of their microbial community structure. Therefore, it suggests that molecular technique is useful for monitoring the clogging problems in sewer lines.

• Journal of the Korean Society of Tobacco Science
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• v.21 no.2
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• pp.136-143
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• 1999

This study was conducted to evaluate the degradation characteristics of waste cigarette filters under 0, 5, 10, and 15cm in depth from soil surface by environmental conditions. Weather was the most important factor during degradation of waste cigarette filters in this study. Bulking of cellulose acetate filaments exposed on soil surface was observed after 2 months, but the form of filter was kept up after 12 months. The treated cigarette filters in soil landfill revealed a little different degradation pattern at each soil landfill depth, The sample in 5cm depth of soil was more degraded then other site. A fluffy appearance of cellulose acetate filaments in the control filter rods was also developed more strongly in soil landfill then on soil surface. From the observation of waste cigarette filters by scanning electron microscopy, much degradation of the fiber of waste cigarette filters could be ascertained in soil landfill. The weight of waste cigarette filters under 5cm from soil surface was reduced about 50%, and the tensile strength of the samples in soil surface and under 5cm from soil surface were reduced 66.0% and 92.4%, respectively. The microbial experiment date that the viable cell number in microbial population and cellulolytic microorganisms showed the maximum values under 5cm from soil surface, suggest that microorganisms in soil play an important roll in the degradation of acetate cigarette filters.

• Journal of Applied Biological Chemistry
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• v.43 no.3
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• pp.165-169
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• 2000

Regarding to maturity evaluation of pig manure compost mixed with saw dust, change of constituents of organic matter influenced by microbial activities were investigated. Throughout the two stages of active composting period, we obtained a lot of data related to compost stabilization. However, we found out that only a couple of parameters could be used for adequate evaluation of compost. We, therefore, decided that total sugar and reducing sugar could be used for the reasonable standard criteria of maturity during composting process, even though some enzyme activities by phosphates and cellulase reactions were obtained and compared. Because the other parameters such as contents of lignin, cellulose, and organic acids were difficult to be used for maturity evaluation of pig manure compost.

• Journal of Microbiology and Biotechnology
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• v.5 no.5
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• pp.280-284
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• 1995

Aspergi11us niger F-580, a potent producer of aminopeptidase M inhibitor, was isolated from the brown spots of plant leaves with a pathological trait. The inhibitory activity was found only in the fungal mat formed by surface culture of Aspergi11us niger F-580, but not in the culture supernatant or cell pellet. The inhibitor was purified from the hot water extract of this fungal mat by using chromatographies on Diaion HP-20, DEAE-cellulose, Sephadex G-l0 and YMC-ODS-AQ columns. The purified inhibitor was analyzed by UV, mass, and NMR spectroscopies, and identified as OF494911, which had been isolated as an aminopeptidase B inhibitor from Penicillium rugulosum OF4949

• Korean Journal of Pharmacognosy
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• v.27 no.3
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• pp.224-230
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• 1996

To find pharmacologically active hybrids among the inter-order protoplast fusants of Lentinula edodes and Ginoderma lucidam the antitumor test was performed and the fusant P22 was selected among them. The hot water and alkaline extracts from the cultured mycelia of P22 were purified and separated into four fractions by DEAE-cellulose anion exchange chromatography. When a dose of 20 mg/kg/day of each fractions was injected into ICR mice by i.p., the tumor inhibition ratio of Fr. IV against solid sarcoma 180 was the higher than any other fraction. Fr. IV was a protein-bound polysaccharide which was composed of 69. 12% polysacchafide and 9.76% protein and the molecular weight of Fr. IV was $6.7{\times}10^4$ dalton.

• Mycobiology
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• v.32 no.4
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• pp.170-172
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• 2004

The efficiency of acid, enzyme and microbial pretreatment of rice bran was compared based on the content of cellulose, hemicellulose, reducing sugars and xylose in the substrate. An isolate of Aspergillus niger or a strain of Trichoderma viride(MTCC 800) was employed for microbial pretreatment of rice bran in solid state. Acid pretreatment resulted in the highest amount of reducing sugars followed by enzyme and microbial pretreatment. A. niger showed a higher rate of hydrolysis than T. viride. The rice bran hydrolysate obtained from the different methods was subsequently fermented to ethanol either by Zymomonas mobilis(NCIM 806) or by Pichia stipitis(NCIM 3497). P. stipitis fermentation resulted in higher ethanol(37% higher) and biomass production($76{\sim}83%$ higher) than those of Z. mobilis. Maximum ethanol production resulted at 12h in Zymomonas fermentation, while in Pichia fermentation, it was observed at 60h. Microbial pretreatment of rice bran by A. niger followed by fermentation employing P. stipitis was more efficient but slower than the other microbial pretreatment and fermentation.

• Korean Journal of Pharmacognosy
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• v.24 no.3
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• pp.203-212
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• 1993

To find antitumor components in the hot water extract of the cultured mycelia of Ganoderma lucidum, protein-bound polysaccharides were purified and fractionated (Fr. I-V) by DEAE-cellulose ion exchange column chromatography and Sepbarose CL-4B gel filtration. When a dose of 20 mg/kg/day of each was, i.p., injected into ICR mice, the inhibition ratios against the solid form of sarcoma 180 were $64.2{\sim}75.8%$. The antitumor component was examined for immunological activity. It increased the amount of superoxide anion released by induced macrophages in peritoneal cavity to 1.8 times and the count of hemolytic plaque-forming cells (PFC) was increased to 4.4 times as compared with those of the control group. It contained 68.6% polysaccharide which consisted of mannose, glucose, galactose, fucose and xylose and 5.1% protein consisting of 17 amino acids. The contents of hexosamine were 0.78%. The molecular weight of Fr. V that showed the highest antitumor activity was $5.8{\times}10^4$ dalton by Sepharose CL-4B gel filtration. It was named lucidan.