• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.449-452
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• 2002

A filamentous microorganism was isolated from completely rotten wood for the production of cellulolytic enzyme. The Trichoderma sp. FJ1 produced a large amount of cellulolytic enzymes, such as CMC, xylanase, ${\beta}-glucosidase$, and avicelase. For the production of the enzymes, when cellulolsic wastes were used as carbon sources of strain FJ1, rice straw showed higher enzyme activities than sawdust and pulp. The activities of CMC, xylanase, ${\beta}-glucosidase$, and avicelase were 2.95, 5.89, 0.45, and 0.12 U/ml in use of rice straw, respectively. To enhance production of the enzymes, the mixture substrate of rice straw and commercial cellulosic materials was investigated as carbon sources. The highest activities of CMCase, ${\beta}-glucosidase$, and avicelase were found in the mixture of rice straw and avicel, particularly rice straw:avicel (50:50), and the highest xylanase was obtained in the mixture ratio of 71:29. Bacto peptone addition of 0.1% showed enhanced production of the cellulolytic enzymes in which the activities of CMCase, xylanase ${\beta}-glucosidase$, and avicelase were 19.23, 27.18, 1.28, and 0.53 U/ml, respectively. The production of the enzymes using rice straw was efficiently induced in present of avicel and pulp containing high content of cellulose. Consequently, the filamentous microorganism, strain FJ1 utilized various cellulosic wastes as carbon sources and cellulases productivities were excellent compared to those of others strains reported previously, suggesting that the strain FJ1 will be expected as a favorable candidate for biological saccharification of cellulosic wastes in further.

• Journal of Life Science
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• v.15 no.4 s.71
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• pp.633-640
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• 2005

The purified xylanase from Bacillus pumilus TX703 was modified with various chemical modifiers to determine the active sites of the enzyme. Treatment of the enzyme with group-specific reagents such as carbodiimide or N-bromosuccinimide resulted in complete loss of enzyme activity. These results assumed that these reagents reacted with glutamic acid or aspartic acid and tryptophan residues located at or near the active site. In each case, inactivation was performed by pseudo first-order kinetics. Inhibition of enzyme activity by carbodiimide and W-bromosuccinimide showed non-competitive and competitive inhibition type, respectively. Addition of xylan to the enzyme solution containing N-bromosuccinimide prevented the inactivation, indicating the presence of tryptophan at the substrate binding site. Analysis of kinetics for inactivation showed that the loss of enzyme activity was due to modification of two glutamic acid or aspartic acid residues and single tryptophan residue.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.337-340
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• 2001

The production of xylanase from Aspergillus niger mutant in SSF was optimized by' using statistical experimental designs. An inoculum size of $5{\times}10^5$ spores/g. initial moisture content of 65 %. cultivation time of 5 days and 10 times concentration of basal medium containing 50 times concentration of CSL were optimum for xylanase production ‘ Under the optimized conditions. the activity and productivity of xytanase obtained after 5 days of fermentation were 5.071 IU/gram of rice straw and 14.790 IU/l.h. respectively.

• Microbiology and Biotechnology Letters
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• v.25 no.1
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• pp.15-22
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• 1997

A bacterial strain J-59 was isolated from a humus soil, which produced simultaneously a thermostable glucose isomerase as well as xylanase. The morphological, cultural and physiological characteristics of the isoisomerase strain J-59 were detemined by the use of the media and methods described in International Streptomyces Project. The chemotaxonomic characteristics of the isolated strain J-59 were determined by the analysis of G+C molar % of DNA, diaminipimelic acid, composition of fatty acid and menaquinone. As the results of various examinations, the strain J-59 was identified to be Streptomyces chibaensis. This strain produced glucose isomerase intracellularly and xylanase extracellularly when grown in a medium containing xylan, but it was not able to utilize the xylose or xylan as a carbon source. The glucose isomerase of S. chibaensis J59 was highly thermostable, which retained more than 75% activity in the presence of Co$^{2+}$ at 80$\circ $C for 72 h.

• Microbiology and Biotechnology Letters
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• v.24 no.6
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• pp.687-692
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• 1996

Xylanase (EC 3.2.1.8) was purified approximately 4.3 fold from Aspergillus niger SFN-416 by ammonium sulfate fractionation, Sephadex G-100 gel filtration and DEAE-Sephacel ion exchange chromatography. Molecular weight of the enzyme was approximately 42,000 daltons. The optimum pH and temperature of the enzyme activity were 5.5 and 50$\circ$C, respectively. The enzyme activity was enhanced by Fe$^{2+}$, and inhibited by Hg$^{2+}$. The activity was decreased by addition of methanol, ethanol, isopropanol and 1-butanol at a concentration of 10%(v/v).

• Journal of Microbiology and Biotechnology
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• v.11 no.3
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• pp.534-538
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• 2001

The xynA gene encoding an alikali-tolerant endo-1,4-${\beta}$-xylanase (XYN) was cloned from the alkalophilic Bacillus pumilus A-30. The nucleotide sequence of a 974-bp DNA fragment containing the xynA was determined. An ORF of 684 nucleotides that encoded a protein of 228 amino aicds was detected. Asparagine-71 of XYN from B. Pumilus A-30 showed to be highly conservative in alkaline xylanases of family G/11, upon comparing the amino acid sequences of 17 family G/11 xylanases. Site-directed mutation of N71D of the xynA gene resulted in a decrease of 12.4% in the specific acitivity and a significant decline in the enzyme activity in the alkaline pH range.

• Mycobiology
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• v.39 no.4
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• pp.306-309
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• 2011

Cladosporium cladosporioides H1 was found to be the most abundant microbe in Janggyeong Panjeon. C. cladosporioides H1 produced a 20 kDa xylanase, which was generally stable below $60^{\circ}C$ and had specialized activity in an acidic condition. Our results may lead to the development of a strategy for preservation of organic cultural heritage environments.

• Journal of Microbiology and Biotechnology
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• v.32 no.5
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• pp.663-671
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• 2022

The saccharification of cellulose and hemicellulose is essential for utilizing lignocellulosic biomass as a biofuel. While cellulose is composed of glucose only, hemicelluloses are composed of diverse sugars such as xylose, arabinose, glucose, and galactose. Sulfolobus acidocaldarius is a good potential candidate for biofuel production using hemicellulose as this archaeon simultaneously utilizes various sugars. However, S. acidocaldarius has to be manipulated because the enzyme that breaks down hemicellulose is not present in this species. Here, we engineered S. acidocaldarius to utilize xylan as a carbon source by introducing xylanase and β-xylosidase. Heterologous expression of β-xylosidase enhanced the organism's degradability and utilization of xylooligosaccharides (XOS), but the mutant still failed to grow when xylan was provided as a carbon source. S. acidocaldarius exhibited the ability to degrade xylan into XOS when xylanase was introduced, but no further degradation proceeded after this sole reaction. Following cell growth and enzyme reaction, S. acidocaldarius successfully utilized xylan in the synergy between xylanase and β-xylosidase.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.10
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• pp.1501-1509
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• 2003

The simultaneous addition of xylanase (5,600 EXU/kg) and phytase (500 FTU/kg) feed enzymes to wheat-based broiler diets was investigated. Starter, grower and finisher diets, with three tiers of nutrient specifications, were fed to 1,440 broiler chicks kept on deep litter from 1-42 days post-hatch, without and with xylanase plus phytase, to determine the effects of diet type and enzyme supplementation on growth performance. The nutrient specifications of type A diets were standard; energy density and protein/amino acid levels were reduced on a least-cost basis to formulate type B diets and further reduced to type C diets. Phosphorus (P) and calcium (Ca) levels were adjusted in supplemented diets. From 1-42 days post-hatch, diet type significantly influenced growth performance. Birds on type C diets had lower growth rates (2,429 vs. 2,631 g/bird; p<0.001), higher feed intakes (4,753 vs. 4,534 g/bird; p<0.005) and less efficient feed conversion (1.96 vs. 1.72; p<0.001) than birds offered type A diets. Enzyme supplementation increased growth rates by 3.2% (2,580 vs. 2,501 g/bird; p<0.005) and improved feed efficiency by 2.7% (1.80 vs. 1.85; p<0.05) over the entire feeding period. There were no interactions between diet type and enzyme supplementation. At 21 days, 5 out of 30 birds per pen were transferred to cages to ascertain treatment effect on apparent metabolisable energy (AME) and nitrogen (N) retention. Xylanase plus phytase enhanced AME (13.48 to 13.91 MJ/kg DM; p<0.001) and N retention (56.3 to 59.7%; p<0.005). Carcass and breast weights of the caged birds were determined following commercial processing. Diet type significantly influenced breast weight, carcass weight and yield. Birds offered Type A diets, in comparison to Type C diets, supported heavier breast (467 vs. 424 g; p<0.001) and carcass weights (1,868 vs. 1,699 g; p<0.001) with superior carcass yields (71.8 vs. 70.6%; p<0.005). Enzyme addition increased carcass weight by 3.9% (1,752 vs. 1,821 g; p<0.005) and breast weight by 5.8% (431 vs. 456 g; p<0.01) without influencing yields. Feed ingredient costs per kg live weight gain and per kg carcass weight indicated that enzyme addition was economically feasible, where supplementation of Type A diets generated the most effective results. Importantly, soluble and total non-starch polysaccharide and phytate contents of the wheat used were typical by local standards. This study confirms the potential of supplementing wheat-based broiler diets with xylanase plus phytase but further investigations are required to define the most appropriate inclusion rates and dietary nutrient specifications in this context.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.1
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• pp.50-58
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• 2013

A facultative bacterium producing cellulolytic and hemicellulolytic enzymes was isolated from the rumen of a native Korean goat. The bacterium was identified as a Bacillus licheniformis on the basis of biochemical and morphological characteristics and 16S rDNA sequences, and has been designated Bacillus licheniformis JK7. Endoglucanase activities were higher than those of ${\beta}$-glucosidase and xylanase at all temperatures. Xylanase had the lowest activity among the three enzymes examined. The optimum temperature for the enzymes of Bacillus licheniformis JK7 was $70^{\circ}C$ for endoglucanase (0.75 U/ml) and $50^{\circ}C$ for ${\beta}$-glucosidase and xylanase (0.63 U/ml, 0.44 U/ml, respectively). All three enzymes were stable at a temperature range of 20 to $50^{\circ}C$. At $50^{\circ}C$, endoglucanse, ${\beta}$-glucosidase, and xylanase had 90.29, 94.80, and 88.69% residual activity, respectively. The optimal pH for the three enzymes was 5.0, at which their activity was 1.46, 1.10, and 1.08 U/ml, respectively. The activity of all three enzymes was stable in the pH range of 3.0 to 6.0. Endoglucanase activity was increased 113% by $K^+$, while $K^+$, $Zn^+$, and tween 20 enhanced ${\beta}$-glucosidase activity. Xylanase showed considerable activity even in presence of selected chemical additives, with the exception of $Mn^{2+}$ and $Cu^{2+}$. The broad range of optimum temperatures (20 to $40^{\circ}C$) and the stability under acidic pH (4 to 6) suggest that the cellulolytic enzymes of Bacillus licheniformis JK7 may be good candidates for use in the biofuel industry.