• 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.

• 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.

• Animal Bioscience
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• v.34 no.6
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• pp.1049-1060
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• 2021

Objective: This study assessed the effect of different levels of xylanase, β-glucanase and phytase on intestinal enzyme activities and tibia bone development in broiler chickens fed wheat-based diets. Methods: Twelve experimental diets were formulated using a 3×2×2 factorial design (three doses of phytase and two doses of both xylanase and β-glucanase) and offered to 648 day-old Ross 308 male chicks having 6 replicates groups with 9 birds per replicate and lasted for 35 days. Results: An interaction between the enzymes products improved (p<0.01) the activity of chymotrypsin. Protein content at d 10 was highest (p<0.001) with addition of phytase while general proteolytic activity (GPA) (p<0.02) and lipase activity (p<0.001) were decreased. At d 24, there were improvements in protein content (p<0.01) and lipase (p<0.04) with supplementation of superdose phytase. Addition of superdose phytase decreased in chymotrypsin (p<0.02), trypsin (p<0.01) and GPA (p<0.001). The optimum dose of xylanase decreased the chymotrypsin activity (p = 0.05), while the GPA (p<0.001) was increased with the optimum level of β-glucanase. Superdose phytase supplementation at d 10 improved maltase (p = 0.05), sucrase (p<0.001) and alkaline phosphatase (p<0.001) activities in the jejunum while aminopeptidase activity was highest (p<0.005) with the low level of phytase. Protein content of jejunum mucosa was bigger (p<0.001) in birds fed superdose phytase while maltase activity (p<0.001) at d 24 was reduced by this treatment. Sucrase (p<0.04) and aminopeptidase activities (p<0.001) improved when diets supplemented with low levels of phytase. Tibia bone breaking strength was highest (p<0.04) with addition of low level of superdose phytase or optimum level of β-glucanase. Bone dry matter content decreased (p<0.04) when diets supplemented with phytase. Conclusion: From the results obtained in this study, supplementation of superdose phytase was the most effective, however, the cost-benefit analysis of the use of such a dose needs to be evaluated.

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.775-784
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• 2017

A neutral xylanase (CcXyn) was identified from Coprinus cinereus. It has a single GH10 catalytic domain with a basic amino acid-rich extension (PVRRK) at the C-terminus. In this study, the wild-type (CcXyn) and C-terminus-truncated xylanase ($CcXyn-{\Delta}5C$) were heterologously expressed in Pichia pastoris and their characteristics were comparatively analyzed with aims to examine the effect of this extension on the enzyme function. The circular dichorism analysis indicated that both enzymes in general had a similar structure, but $CcXyn-{\Delta}5C$ contained less ${\alpha}-helices$ (42.9%) and more random coil contents (35.5%) than CcXyn (47.0% and 32.8%, respectively). Both enzymes had the same pH (7.0) and temperature ($45^{\circ}C$) optima, and similar substrate specificity on different xylans. They all hydrolyzed beechwood xylan primarily to xylobiose and xylotriose. The amounts of xylobiose and xylotriose accounted for 91.5% and 92.2% (w/w) of total xylooligosaccharides (XOS) generated from beechwood by CcXyn and $CcXyn-{\Delta}5C$, respectively. However, truncation of the C-terminal 5-amino-acids extension significantly improved the thermostability, SDS resistance, and pH stability at pH 6.0-9.0. Furthermore, $CcXyn-{\Delta}5C$ exhibited a much lower $K_m$ value than CcXyn (0.27 mg/ml vs 0.83 mg/ml), and therefore, the catalytic efficiency of $CcXyn-{\Delta}5C$ was 2.4-times higher than that of CcXyn. These properties make $CcXyn-{\Delta}5C$ a good model for the structure-function study of $({\alpha}/{\beta})_8$-barrel-folded enzymes and a promising candidate for various applications, especially in the detergent industry and XOS production.

• Korean Journal of Microbiology
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• v.36 no.3
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• pp.196-202
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• 2000

A gene for cellulolytic xylanase of Bacillus circulnns ATCC21365 was cloned on pUC 19 in Eschwichia coli. The recombinant plasniid pXLI80 contained an 1.8 id, inselt composed of0.5 kb and 1.3 kb PslI fragments derived from B, circulans. The 0.5 kh fragment in the upstream region of 1.3 kb one was confirmed lo be indispensable for not only expression but also hyperexpression of the cloned gene. The transformant overproduced the xylanase 135 times greater than that produced by the orlginal B circulnns. The optimum pH and temperature of the cloned enzyme we]-e pH 5.2 and $60^{\circ}C$, respectively. Heal pretl-eatment at TEX>$55^{\circ}C$C for 1 Indid not cause inhibition of the activity of this enzyme. The elm.ynie could hydl-olyre CMC and lichenan as well as xylan to produce xylose(or GI), xylohiose(or G2) and xylolnose(or G3) as inah products. Hence We defined the cloned enzyme as a cellulolytic xylanase. The SDS-PAG electrophoretic mobility and zyiiogram of this enzyme derived from whole cell extracts or c~~lture supematants or E. coli(pXL180) indicated a molecular weight of 45,000 and nonprocessing of the enzyme in the peilplasln of E. coli.

• Journal of Animal Science and Technology
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• v.48 no.3
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• pp.415-424
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• 2006

The purpose of this study was to investigate the fungal growth and enzyme production under different carbohydrate substrate conditions. The anaerobic fungus Neocallimastix sp. NLRI-3 isolated from the rumen of Korean native goat was incubated with different carbohydrate media containing 0.2% of glucose, starch, rice straw, filter paper, carboxymethyl cellulose(CMC), Sigmacell cellulose, xylan or xylose, respectively. The culture head gas production was the highest in the culture of filter paper medium, and the lowest in the culture of CMC medium at 96h incubation (P<0.05). The fungal zoospore production reached peak at 72h incubation, and its number was the highest in rice straw medium among the treatments (P<0.05). At 96h incubation, carboxymethyl cellulase(CMCase) activity was the highest in the culture of filter paper medium and the lowest in the culture of starch medium (P<0.05). While xylanase activity was the highest in the culture of rice straw medium and the lowest in the culture of xylose medium(P<0.05) at 72h incubation. There were no differences in culture supernatant protein expression among the treatments. However, the patterns of enzyme expression were different among the treatments with zymogram analysis. Six CMCases and 4 xylanase were detected from the results of zymogram analysis. Therefore the present study indicating that the fungal enzyme expression could be stimulated with insoluble substrates in the culture medium.

• Journal of Mushroom
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• v.13 no.4
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• pp.305-309
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• 2015

In order to isolate compost-promoting bacteria with high activity of cellulase and xylanase, spent mushroom substrates with sawdust were collected from mushroom cultivation farm, Jinju, Gyeongnam in Korea. Among of the isolates, one strain, designated CA105 was selected by agar diffusion method. The strain CA105 was identified as members of the Bacillus subtilis by biochemical characteristics using VITEK 2 system. Comparative 16S rRNA gene sequence analysis showed that isolate CA105 formed a distinct phylogenetic tree within the genus Bacillus and was most closely related to Bacillus subtilis with 16S rRNA gene sequence similarity of 98.9%. On the basis of its physiological properties, biochemical characteristics and phylogenetic distinctiveness, isolate CA105 was classified within the genus Bacillus subtilis, for which the name Bacillus subtilis CA105 is proposed. The cellulase and xylanase activity of B. subtilis CA105 was slightly increased according to bacterial population from exponential phase to stationary phase in growth curve for Bacillus sp. CA105.

• Korean Journal of Microbiology
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• v.22 no.2
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• pp.97-101
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• 1984

To investigate the biodegradation pattern of rice straw, mainly composed of cellulose, hemicellulose and lignin components, by the isolate stran Bacillus subtilis $DO_4$, the change of cell population was observed on CMC (carboxymethyl cellulose), larch wood xylan and lignosulfonate as a carbon source respectively. Also, the transition pattern of enzyme activities of cellulase and xylanase and lignin contents was measured on rice straw and mixed substrate according to growth. The results in these experiments revealed that xylanase activity was first appeared and cellulase activity in the next, while lignin component was almost not changed through the culture period.

• Microbiology and Biotechnology Letters
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• v.48 no.2
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• pp.215-222
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• 2020

The marine microorganism PX-1, which can hydrolyze xylan, was isolated from coastal sea water of Jeju Island, Korea. Based on the 16S rRNA gene sequence and chemotaxonomy analysis, PX-1 was identified as a species of the genus Aestuariibacter and named Aestuariibacter sp PX-1. From the culture broth of PX-1, an extracellular xylanase was purified to homogeneity through ammonium sulfate precipitation and subsequent adsorption chromatography using insoluble xylan. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration chromatography estimated the molecular weight of the purified putative xylanase (XylA) as approximately 64 kDa. XylA showed xylanase activity toward beechwood xylan, with a maximum enzymatic activity at pH 6.0 and 45℃. Through thin-layer chromatographic analysis of the xylan hydrolysate produced by XylA, it was confirmed that XylA is an endo-type xylanase that decomposes xylan into xylose and xyloligosaccharides of various lengths. The K_m and V_max values of XylA for beechwood xylan were 27.78 mM and 78.13 μM/min, respectively.