• Korean Journal of Microbiology
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• v.42 no.1
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• pp.67-72
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• 2006

The nucleotide sequence of the cloned cellulolytic xylanase gene (bglBC2) from B. circulans ATCC21367 was determined. bglBC2 consists of an 1,224 bp open reading frame (ORF) coding for a polypeptide of 407 amino acids with a deduced molecular weight of 45 kDa. The Shine-Dalgarno (SD) sequence (5'-AAAGGAG-3') was found 9 bp upstream of the initiation codon, ATG. A promoter region corresponding closely to the B. subtilis consensus sequence (-35: TTGACA,-10: TATAAT) was detected, the putative -35 and -10 sequences of which were TTTACA and TATACT, respectively. The deduced amino acid sequence of the cellulolytic xylanase showed 97% homology with that of the alkaline $endo-\beta-1,4-glucanase$ from B. circulans KSM-N257, 75% homology with that of the $endo-\beta-1,3-1,4-glucanase$ from B. circulans WL-12, and 45% homology with that of the $endo-\beta-1,4-glucanase$ (cellulase) from Bacillus sp. KSM-330. The bglBC2 sequence was deposited in Gen-Bank under the accession number AY269256.

• Microbiology and Biotechnology Letters
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• v.41 no.3
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• pp.263-271
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• 2013

A xylanase-producing bacterium was isolated from a soil sample collected in Yongin city, Korea. The strain was aerobic and gram positive, and grew between pH 5.0 and 11.0, forming a yellow-colored colony. The strain was classified as a novel subspecies bacterium of Paenibacillus barcinonensis by 16S rRNA gene sequence similarity, phylogenetic analysis, phenotypic, and biochemical characteristics, and thus named Paenibacillus sp. HX-1. This strain produced extracellular endo-${\beta}$-1,4-xylanase, and the best xylanolytic activity (205.17 unit/ml) was obtained at 96 h in an optimized TNX medium containing 1% (w/v) bacto tryptone, 1% (w/v) NaCl, and 0.7% (w/v) beechwood xylan at pH 7.0, $37^{\circ}C$ and 200 rpm. The endo-${\beta}$-1,4-xylanase produced by the strain HX-1 yielded xylobiose as the end product from beechwood xylan hydrolysis. The enzyme exhibited optimum pH and temperature at pH 7.0 and $45^{\circ}C$, respectively. The remarkable enhancing effect of the TNX medium on xylanase production by HX-1, in spite of its simple formula, may have great advantages for industrial applications of xylanase.

• BMB Reports
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• v.38 no.1
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• pp.17-23
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• 2005

During the screening of xylanolytic enzymes from locally isolated fungi, one strain BCC14405, exhibited high enzyme activity with thermostability. This fugal strain was identified as Aspergillus cf. niger based on its morphological characteristics and internal transcribed spacer (ITS) sequences. An enzyme with xylanolytic activity from BCC14405 was later purified and characterized. It was found to have a molecular mass of ca. 21 kDa, an optimal pH of 5.0, and an optimal temperature of $55^{\circ}C$. When tested using xylan from birchwood, it showed $K_m$ and $V_{max}$ values of 8.9 mg/ml and 11,100 U/mg, respectively. The enzyme was inhibited by $CuSO_4$, EDTA, and by $FeSO_4$. The homology of the 20-residue N-terminal protein sequence showed that the enzyme was an endo-1,4-$\beta$-xylanase. The full-length gene encoding endo-1,4-$\beta$-xylanase from BCC14405 was obtained by PCR amplification of its cDNA. The gene contained an open reading frame of 678 bp, encoding a 225 amino acid protein, which was identical to the endo-1,4-$\^{a}$-xylanase B previously identified in A. niger.

• Journal of Microbiology and Biotechnology
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• v.19 no.8
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• pp.823-828
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• 2009

An endo-${\beta}-1$,4-xylanase (${\beta}$-xylanase) from Trichoderma harzianum C4 was purified without cellulase activity by sequential chromatographies. The specific activity of the purified enzyme preparation was 430 units/mg protein on D-xylan. The complementary DNA (cDNA) encoding ${\beta}$-xylanase (xynII) was amplified by PCR and isolated from cDNA PCR libraries constructed from T. harzianum C4. The nucleotide sequence of the cDNA fragment contained an open reading frame of 663 bp that encodes 221 amino acids, of which the mature protein is homologous to several ${\beta}$-xylanases II. An intron of 63 bp was identified in the genomic DNA sequence of xynII. This gene was expressed in Saccharomyces cerevisiae strains under the control of adh1 (alcohol dehydrogenase I) and pgk1 (phosphoglycerate kinase I) promoters in 2 ${\mu}$-based plasmids, which could render recombinants able to secrete ${\beta}$-xylanase into the media.

• Mycobiology
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• v.39 no.2
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• pp.121-124
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• 2011

The cDNA of endo-1,$4-{\beta}-xylanaseA$, isolated from Phaenerocheate chrysosporium was expressed in Pichia pastoris. Using either the intrinsic leader peptide of XynA or the ${\alpha}$-factor signal peptide of Saccharomyces cerevisiae, xylanaseA is efficiently secreted into the medium at maximum concentrations of 1,946 U/L and 2,496 U/L, respectively.

• Korean Journal of Microbiology
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• v.32 no.4
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• pp.306-314
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• 1994

The action mode of xylanase II from Trichoderma koningii ATCC 26113 on xylan and related oligosaccharides (xylotriose, xylotetraose, and arabinoxylotriose) indicated that xylanase II is an endo-enzyme and also has trans-xylosidase activity. The $^1HNMR$-NMR studies of the reaction products formed by xylanase II revealed that all the hydrolysis products of xylooligosaccharides by the enzyme have only ${\beta}$-1,4-xylosidic linkage(s). Chemical modification of the enzyme with iodoacetamide showed that two cysteine residues per molecule of the enzyme was essential for the activity. Modification of the enzyme with N-bromosuccinimide demonstrated that four of the eight tryptophan residues were involved in its active site.

• Journal of Microbiology and Biotechnology
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• v.24 no.7
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• pp.943-953
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• 2014

The XylH gene (1,167-bp) encoding a novel hemicellulase (41,584 Da) was identified from the genome of Microbacterium trichothecenolyticum HY-17, a gastrointestinal bacterium of Gryllotalpa orientalis. The enzyme consisted of a single catalytic domain, which is 74% identical to that of an endo-${\beta}$-1,4-xylanase (GH10) from Isoptericola variabilis 225. Unlike other endo-${\beta}$-1,4-xylanases from invertebrate-symbiotic bacteria, rXylH was an alkali-tolerant multifunctional enzyme possessing endo-${\beta}$-1,4-xylanase activity together with ${\beta}$-1,3/${\beta}$-1,4-glucanase activity, which exhibited its highest xylanolytic activity at pH 9.0 and 60oC, and was relatively stable within a broad pH range of 5.0-10.0. The susceptibilities of different xylosebased polysaccharides to the XylH were assessed to be as follows: oat spelts xylan > beechwood xylan > birchwood xylan > wheat arabinoxylan. rXylH was also able to readily cleave p-nitrophenyl (pNP) cellobioside and pNP-xylopyranoside, but did not hydrolyze other pNP-sugar derivatives, xylobiose, or hexose-based materials. Enzymatic hydrolysis of birchwood xylan resulted in the product composition of xylobiose (71.2%) and xylotriose (28.8%) as end products.

• Journal of the Korean Wood Science and Technology
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• v.46 no.6
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• pp.670-680
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• 2018

Acanthophysium sp. KMF001, a wood rotting fungus, produces a strong crude enzyme complex that efficiently produces simple sugars from wood. The transcriptomic analysis of Acanthophysium sp. KMF001 identified 14 genes for putative glycoside hydrolases. Among them, isotig01043 was expressed heterogeneously in Escherichia coli BL21(DE3), and the expressed protein exhibited an endo-${\beta}$-1,4-xylanase activity which showed the optimum reaction at pH 5.0 and $30^{\circ}C$. The enzyme kinetic values of $K_m$ and $V_{max}$ were 25.92 mg/ml and $0.628{\mu}mole/mg/ml$, respectively. The enzymatic characteristics of the expressed xylanase showed a typical fungal xylanase. However, the bioinformatics analysis suggested that the protein encoded by isotig01043 was a novel xylanase based on a low identity when it was compared with the closest protein in the NCBI database and a similar protein domain with GH16_fungal_Lam16A_glucanase, which had not been earlier suggested as a xylanase.

• Journal of the Korean Wood Science and Technology
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• v.19 no.2
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• pp.22-29
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• 1991

The endo-1,4-${\beta}$-xylanase was extracted and purified from the extracellular xylanolytic systems of Trichoderma viride. The crude enzyme was chromatographed with ion-exchange reins of DEAE Sepharose CL-6B, Sepharose, S-Sepharose CL-6B and the resulting xylanase was turned out to be a single protein as 20KD hy SDS-polyacrylamide gel electrophoresis. The xylooligomers were obtained from xylan by incubation with the purified xylanase up to 50%. The ${\beta}$-xylosidase lost its activity completely by incubation of crude enzyme for 24hr with buffer solution of pH 2.8 at $27^{\circ}C$. And also, the xylooligomers were obtained from xylan as a main product by incubation with the crude enzyme treated with acidic buffer.

• Journal of Microbiology and Biotechnology
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• v.19 no.3
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• pp.277-285
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• 2009

The nucleotide sequence of the Paenibacillus curdlanolyticus B-6 xyn10A gene, encoding a xylanase Xyn10A, consists of 3,828 nucleotides encoding a protein of 1,276 amino acids with a predicted molecular mass of 142,726 Da. Sequence analysis indicated that Xyn10A is a multidomain enzyme comprising nine domains in the following order: three family 22 carbohydrate-binding modules (CBMs), a family 10 catalytic domain of glycosyl hydrolases (xylanase), a family 9 CBM, a glycine-rich region, and three surface layer homology (SLH) domains. Xyn10A was purified from a recombinant Escherichia coli by a single step of affinity purification on cellulose. It could effectively hydrolyze agricultural wastes and pure insoluble xylans, especially low substituted insoluble xylan. The hydrolysis products were a series of short-chain xylooligosaccharides, indicating that the purified enzyme was an endo-$\beta$-1,4-xylanase. Xyn10A bound to various insoluble polysaccharides including Avicel, $\alpha$-cellulose, insoluble birchwood and oat spelt xylans, chitin, and starches, and the cell wall fragments of P. curdlanolyticus B-6, indicating that both the CBM and the SLH domains are fully functioning in the Xyn10A. Removal of the CBMs from Xyn10A strongly reduced the ability of plant cell wall hydrolysis. These results suggested that the CBMs of Xyn10A play an important role in the hydrolysis of plant cell walls.