• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.559-564
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• 1992

To increase the efficency of utilizing cellulosic biomass, a potent xylanase producing bacteria was isolated and identified as Bacillus sp. N-25. Extracellular xylanase from Bacillus sp. N-25 was partially purified by ammonium sulfate precipitation, DEAE-Sephadex A-25 and Sephadex G-IOO column chromatographies. The xylanase was single fraction on chromatography and was true xylanase without cellulase activity. The enzyme was stable at pH 6-8 and 80% activity was remained at $50^{\circ}C$ for 30 min, but was inhibited by $Hg^{2+}$, $Ag^{2+}$, and $Mn^{2+}$. From the fact that the major end product was xylose, we suggested that the enzyme is an exo-xylanase which may be a prime candidate for industrial use.

• Microbiology and Biotechnology Letters
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• v.16 no.6
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• pp.499-504
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• 1988

Among the new yeast strains which were isolated from soils by incubating in the xylan containing minimal medium at 3$0^{\circ}C$, one strain(XB-33) was finally selected by the results of extracellular xylanase production test. The characteristics of XB-33 was almost consistent with those of the Cryptococcus ater. The formation of xylanase activity was induced by xylan and repressed by xylose or glucose. The xylanase was partially purified from the culture supernatant with DEAE-Sephadex A5O chromatography. The enzyme had a pH optimum for activity at 5.0 and its stability range was pH 5-7. The temperature optimum was at 5$0^{\circ}C$, but the enzyme activity was greatly lost by heating at 7$0^{\circ}C$ for 60 minutes. The hydrolysis products from xylan by crude enzyme detected by TLC, were xylose and n series of higher oligosaccharides. The Km value of xylanase was 20 (mg/ml).

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.4 s.112
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• pp.1-7
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• 2005

This study was carried out to investigate the characteristics of extracellular cellulase and xylanase from Fusarium pallidoroseum and Aspergillus niger, such as enzyme activity and stability by various pH, temperature and metal ions, for application into enzymatic deinking system. The optimal temperature and pH for enzyme activity and stability of Fusarium pallidoroseum and Aspergillus niger were $50^{\circ}C$, pH 5.0 and $60^{\circ}C$, pH 9.0, respectively. Certain metal ions, calcium and cobalt, brought to elevate cellulase and xylanase activity from F. pallidoroseum and A. niger. With these results we suggest that enzymatic deinking system should be proceed at $50\~60^{\circ}C$ under their optimal pH condition.

• Journal of Life Science
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• v.17 no.4 s.84
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• pp.568-574
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• 2007

Lignin degrading bacterium Pseudomonas sp. LG2 was able to degrade lignin substrate to a lot of APPL compound. APPL compound was detected in culture supernatants from Pseudomonas sp. LG2 grown with BSC(brewer's spent grain). FAE(ferulic acid esterase) and xylanase are induced from Pseudomonas sp. LG2 in the presence of carbon sources such as oat spelt xylan, HBSG I, II(hydrolyzed brewer's spent grain I, II) and AFBSG(autoclaved fraction from brewer's spent grain). However, xylanase and FAE are not induced by growth of Pseudomonas sp. LG2 on xylose and arabinose. Pseudomonas sp. LG2 is grown on medium containing oat spelt xylan, HBSG I, II and AFBSG and the induction of FAE and xylanase activities of extracellular proteins determined during 14 days. Maximum level of xylanase activity(5.3 U/mg) found at 6 days in culture contained oat spelt xylan as carbon source, whereas maximum level of FAE activity(15.4 mU/mg) was found at 8 days in culture contained AFBSG as carbon source. Most ferulic acid was released in culture supernatants when Pseudomonas sp. LG2 grown on oat spelt xylan, HBSG I, II and AFBSG. FAE of extracellular enzymes was also specific activity on methyl ferulic acid, methyl caffeic acid and methyl p-coumaric acid respectively, but not methyl sinapinic acid, methyl vanillic acid and methyl gallic acid.

• The Korean Journal of Mycology
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• v.26 no.4 s.87
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• pp.496-501
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• 1998

The mycelia of Tricholoma matsutake DGUM 26001, 26101, 26210 and FRI 91024 were used to determine the extracellular enzyme activity in mycelia. When the filtrate of culture broth after 30-day cultivation at $24^{\circ}C$ was used as a crude solution of extracellular enzyme, the average specific activity of ${\alpha}-amylase$ was 6142.3 unit/mg protein. The specific activity of xylanase was comparatively high. However, little or no enzyme activities were found for ${\beta}-glucosidase$, ligninase, CMCase, chitinase, protease, and lipase.

• Journal of Microbiology and Biotechnology
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• v.8 no.4
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• pp.378-387
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• 1998

The DNA sequence immediately following the xynA gene of Bacillus stearothermophilus 236 ［about l-kb region downstream from the translational termination codon (TAA) of the xynA gene］was found to have an ability to enhance the xylanase activity of the upstream xynA gene. An 849-bp ORF was identified in the downstream region, and the ORF was confirmed to encode a novel protein of 283 amino acids designated as XaiF (xylanase-activity-increasing factor). From the nucleotide sequence of the xaiF gene, the molecular mass and pI of XaiF were deduced to be 32,006 Da and 4.46, respectively. XaiF was overproduced in the E. coli cells from the cloned xaiF gene by using the T7 expression system. The transcriptional initiation site was determined by primer extension analysis and the putative promoter and ribosome binding regions were also identified. Blast search showed that the xaiF and its protein product had no homology with any gene nor any protein reported so far. Also, in B. subtilis, the xaiF trans-activated the xylanase activity at the same rate as in E. coli. In contrast, xaiF had no activating effect on the co-expressed ${\beta}-xylosidase$ of the xylA gene derived from the same strain of B. stearothermophilus. In addition, the intracellular and extracellular fractions from the E. coli cells carrying the plasmid-borne xaiF gene did not increase the isolated xylanase activity, indicating that the protein-protein interaction between XynA and XaiF was not a causative event for the xylanase activating effect of the xaiF gene.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.3
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• pp.9-16
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• 2005

This study was carried out to investigate the characteristics of extracellular cellulase and xylanase from 4 selected different species, such as enzyme activity and stability by pH, temperature and metal ions, for application into enzymatic deinking system. The optimal temperature and pH for enzyme activity of Bacillus pumilus I, B. subtilis I, B. pumilus II and B. subtilis II were mainly $40{\sim}60^{\circ}C$ and pH $6.0{\sim}7.0$, respectively. Certain metal ions, calcium and cobalt, elevated enzyme activity, even though there were different results of enzyme activities based on various metal ions in 4 different species. With these results we suggest that enzymatic deinking system should be proceed at $50^{\circ}C$ with neutral pH condition.

• Current Research on Agriculture and Life Sciences
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• v.14
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• pp.111-122
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• 1996

S. chibaensis J-59 produced an extracellular xylanase in a CSL medium composed of 1.5% com steep liquor, 0.1% $MgSO_4{\cdot}7H_2O$, 0.012% $CoCl_2{\cdot}6H_2O$, and 0.15% glucose containing xylan. but it did not produce in the culture medium containing xylose. The production of enzyme reached to a maximum level (0.83 uints/ml) when bacteria were cultured in 2.5 l jar fermentor for 48hrs at $30^{\circ}C$ and pH 7.0. Furthermore, S. chibaensis J-59 produced an intracellular glucose isomerase in a medium containing xylan and/or xylose. Xylanase was purified 29-fold over the culture supernatants of S. chibaensis J-59 by ammonium sulfate fractionation, chromatography on DEAE-Sephadex A-50, and gel filtration on Sephadex G-200. The purified enzyme is a monomeric enzyme with a native molecular mass of 25 kDa and a subunit molecular mass of 25 kDa. The purified enzyme requires $Mg^{2+}$ for activity, $Ca^{2+}$, $Co^{2+}$ is not an inhibitor but inhibit by $Fe^{3+}$, $Hg^{2+}$, and $Cu^{2+}$, sodium dodecyl sulfate, N-bromosuccinide. Pattern of hydrolysis demonstrated that the xylanase was an endo-splitting enzyme able to break down birchwood xylan at random giving xylobiose, xylotriose and xylotetrose as the main end products.

• Mycobiology
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• v.39 no.2
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• pp.118-120
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• 2011

The ability of Ganoderma to produce extracellular enzymes, including ${\beta}$-glucosidase, cellulase, avicelase, pectinase, xylanase, protease, amylase, and ligninase was tested in chromogenic media. ${\beta}$-glucosidase showed the highest activity, among the eight tested enzymes. In particular, Ganoderma neo-japonicum showed significantly stronger activity for ${\beta}$-glucosidase than that of the other enzymes. Two Ganoderma lucidum isolates showed moderate activity for avicelase; however, Ganoderma neojaponicum showed the strongest activity. Moderate ligninase activity was only observed in Ganoderma neo-japonicum. In contrast, pectinase, amylase, protease, and cellulase were not present in Ganoderma. The results show that the degree of activity of the tested enzymes varied depending on the Ganoderma species tested.

• Journal of Microbiology and Biotechnology
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• v.16 no.8
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• pp.1255-1261
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• 2006

An alkaliphilic bacterium, Bacillus sp. strain BK, was found to produce extracellular cellulase-free xylanolytic enzymes with xylan-binding activity. Since the pellet-bound xylanase is eluted with 2% TEA from the pellet of the culture, they contain a xylan-binding region that is stronger than the xylan-binding xylanase of the extracellular enzyme. The xylanases had a different molecular weight and xylan-binding ability. The enzyme activity of xylanase in the extracellular fraction was 6 times higher than in the pellet-bound enzyme. Among the enzymes, xylanase had the highest enzyme activity. When Bacillus sp. strain BK was grown in pH 10.5 alkaline medium containing xylan as the sole carbon source, the bacterium produced xylanase, arabinofuranosidase, acetyl esterase, and $\beta$-xylosidase with specific activities of 1.23, 0.11, 0.06, and 0.04 unit per mg of protein, respectively. However, there was no cellulase activity detected in the crude enzyme preparation. The hydrolysis of agricultural residues and kraft pulps by the xylanolytic enzymes was examined at 50$^{\circ}C$ and pH 7.0. The rate of xylan hydrolysis in com hull was higher than those of sugarcane bagasse, rice straw, com cop, rice husk, and rice bran. In contrast, the rate of xylan hydrolysis in sugarcane pulp was 2.01 and 3.52 times higher than those of eucalyptus and pine pulp, respectively. In conclusion, this enzyme can be used to hydrolyze xylan in agricultural residues and kraft pulps to breach and regenerate paper from recycled environmental resources.