High-level expression of a xylanase gene from the thermophilic fungus Paecilomyces thermophila in Pichia pastoris

A xylanase gene from Paecilomyces thermophila was functionally expressed in Pichia pastoris. The recombinant xylanase (xynA) was predominantly extracellular; in a 5?l fermentor culture, the total extracellular protein was 8.1?g?l^?1 with an activity of 52,940?U?ml^?1. The enzyme was purified to homogeneity with a recovery of 48?%. The recombinant xynA was optimally active at 75?°C, as measured over 10?min, and at pH 7. The enzyme was stable up to 80?°C for 30?min. It hydrolyzed birchwood xylan, beechwood xylan and xylooligosaccharides to produce xylobiose and xylotriose as the main products.     

A new acidophilic endo-β-1,4-xylanase from Penicillium oxalicum: cloning,purification, and insights into the influence of metal ions on xylanase activity

A new acidophilic xylanase (XYN11A) from Penicillium oxalicum GZ-2 has been purified, identified and characterized. Synchronized fluorescence spectroscopy was used for the first time to evaluate the influence of metal ions on xylanase activity. The purified enzyme was identified by MALDI TOF/TOF mass spectrometry, and its gene (xyn11A) was identified as an open reading frame of 706 bp with a 68 bp intron. This gene encodes a mature protein of 196 residues with a predicted molecular weight of 21.3 kDa that has the 100 % identity with the putative xylanase from the P. oxalicum 114-2. The enzyme shows a structure comprising a catalytic module family 10 (GH10) and no carbohydrate-binding module family. The specific activities were 150.2, 60.2, and 72.6 U/mg for beechwood xylan, birchwood xylan, and oat spelt xylan, respectively. XYN11A exhibited optimal activity at pH 4.0 and remarkable pH stability under extremely acidic condition (pH 3). The specific activity, K _m and V _max values were 150.2 U/mg, 30.7 mg/mL, and 403.9 μmol/min/mg for beechwood xylan, respectively. XYN11A is a endo-β-1,4-xylanase since it release xylobiose and xylotriose as the main products by hydrolyzing xylans. The activity of XYN11A was enhanced 155 % by 1 mM Fe²⁺ ions, but was inhibited strongly by Fe³⁺. The reason of enhancing the xylanase activity of XYN11A with 1 mM Fe²⁺ treatment may be responsible for the change of microenvironment of tryptophan residues studied by synchronous fluorescence spectrophotometry. Inhibition of the xylanase activity by Fe³⁺ was first time demonstrated to associate tryptophan fluorescence quenching.     

Cloning,over-expression and characterization of a thermo-tolerant xylanase from Thermotoga thermarum

The xyn10B gene, encoding the endo-1,4-β-xylanase Xyn10B from Thermotoga thermarum, was cloned and expressed in Escherichia coli. The ORF of the xyn10B was 1,095 bp and encoded to mature peptide of 344 amino acids with a calculated MW of 40,531 Da. The recombinant xylanase was optimally active at 80 °C, pH 6.0 and retained approx. 60 % of its activity after 2 h at 75 °C. Apparent K _m , k _cat and k _cat /K _m values of the xylanase for beechwood xylan were 1.8 mg ml^?1, 520 s^?1 and 289 ml mg^?1 s^?1, respectively. The end products of the hydrolysis of beechwood xylan were mainly oligosaccharides but without xylose after 2 h hydrolysis.     

Recombinant xylanase from Streptomyces coelicolor Ac-738: characterization and the effect on xylan-containing products

A xylanase gene was isolated from the genomic DNA of Streptomyces coelicolor Ac-738. The 723-bp full-length gene encoded a 241-amino acid peptide consisting of a 49-residue putative TAT signal peptide and a glycoside hydrolase family-11 domain. The mature enzyme called XSC738 was expressed in Escherichia coli M15[pREP4]. The electrophoretically homogeneous protein with a specific activity of 167 U/mg for beechwood xylan was purified. The pH optimum of XSC738 was at pH 6; a high activity was retained within a pH range of 4.5–8.5. The enzyme was thermostable at 50–60 °C and retained an activity at pH 3.0–7.0. Xylanase XSC738 was activated by Mn²⁺, Co²⁺ and largely inhibited by Cd²⁺, SDS and EDTA. The products of xylan hydrolysis were mainly xylobiose, xylotriose, xylopentaose and xylohexose. Xylotetraose appeared as a minor product. Processing of such agricultural xylan-containing products as wheat, oats, soy flour and wheat bran by xylanase resulted in an increased content of sugars.     

GH52 xylosidase from Geobacillus stearothermophilus: characterization and introduction of xylanase activity by site-directed mutagenesis of Tyr509

A xylosidase gene, gsxyn, was cloned from the deep-sea thermophilic Geobacillus stearothermophilus, which consisted of 2,118 bp and encoded a protein of 705 amino acids with a calculated molecular mass of 79.8 kDa. The GSxyn of glycoside hydrolase family 52 (GH52) displayed its maximum activity at 70 °C and pH 5.5. The K _m and k _cat values of GSxyn for ρNPX were 0.48 mM and 36.64 s^?1, respectively. Interestingly, a new exo-xylanase activity was introduced into GSxyn by mutating the tyrosine509 into glutamic acid, whereas the resultant enzyme variant, Y509E, retained the xylosidase activity. The optimum xylanase activity of theY509E mutant displayed at pH 6.5 and 50 °C, and retained approximately 45 % of its maximal activity at 55 °C, pH 6.5 for 60 min. The K _m and k _cat values of the xylanase activity of Y509E mutant for beechwood xylan were 5.10 mg/ml and 22.53 s^?1, respectively. The optimum xylosidase activity of theY509E mutant displayed at pH 5.5 and 60 °C. The K _m and k _cat values of the xylosidase activity of Y509E mutant for ρNPX were 0.51 mM and 22.53 s^?1, respectively. This report demonstrated that GH52 xylosidase has provided a platform for generating bifunctional enzymes for industrially significant and complex substrates, such as plant cell wall.     

Biochemical and thermodynamic characteristics of thermo-alkali-stable xylanase from a novel polyextremophilic Bacillus halodurans TSEV1

The purified extracellular xylanase of polyextremophilic Bacillus halodurans TSEV1 has been visualized as a single band on SDS-PAGE and eluted as single peak by gel filtration, with a molecular mass of 40 kDa. The peptide finger print and cloned xylanase gene sequence analyses indicate that this enzyme belongs to GH family 10. The active site carboxyl residues are mainly involved in catalysis, while tryptophan residues are involved in substrate binding. The enzyme is optimally active at 80 °C and pH 9.0, and stable in the pH range of 7.0–12.0 with T _1/2 of 35 min at 80 °C (pH 9.0). Activation energy for birch wood xylan hydrolysis is 30.51 kJ mol^?1. The K _m, V _max and k _cat (birchwood xylan) are 2.05 mg ml^?1, 333.33 μmol mg^?1 min^?1 and 3.33 × 10⁴ min^?1, respectively. The pKa₁ and pKa₂ of ionizable groups of the active site that influence V _max are 8.51 and 11.0. The analysis of thermodynamic parameters for xylan hydrolysis suggests this as a spontaneous process. The enzyme is resistant to chemical denaturants like urea and guanidinium-HCl. The site-directed mutagenesis of catalytic glutamic acid residues (E196 and E301) resulted in a complete loss of activity. The birch wood xylan hydrolyzate contained xylobiose and xylotriose as the main products without any trace of xylose, and the enzyme hydrolyzes xylotetraose and xylopentaose rapidly to xylobiose. Thermo-alkali-stability, resistance to various chemical denaturants and mode of action make it a useful biocatalyst for generating xylo-oligosaccharides from agro-residues and bleaching of pulp in paper industries.     

Molecular and biochemical characterization of a new alkaline active multidomain xylanase from alkaline wastewater sludge

A xylanase gene, xyn-b39, coding for a multidomain glycoside hydrolase (GH) family 10 protein was cloned from the genomic DNA of the alkaline wastewater sludge of a paper mill. Its deduced amino acid sequence of 1,481 residues included two carbohydrate-binding modules (CBM) of family CBM_4_9, one catalytic domain of GH 10, one family 9 CBM and three S-layer homology (SLH) domains. xyn-b39 was expressed heterologously in Escherichia coli, and the recombinant enzyme was purified and characterized. Xyn-b39 exhibited maximum activity at pH 7.0 and 60 °C, and remained highly active under alkaline conditions (more than 80 % activity at pH 9.0 and 40 % activity at pH 10.0). The enzyme was thermostable at 55 °C, retaining more than 90 % of the initial activity after 2 h pre-incubation. Xyn-b39 had wide substrate specificity and hydrolyzed soluble substrates (birchwood xylan, beechwood xylan, oat spelt xylan, wheat arabinoxylan) and insoluble substrates (oat spelt xylan and wheat arabinoxylan). Hydrolysis product analysis indicated that Xyn-b39 was an endo-type xylanase. The K _m and V _max values of Xyn-b39 for birchwood xylan were 1.01 mg/mL and 73.53 U/min/mg, respectively. At the charge of 10 U/g reed pulp for 1 h, Xyn-b39 significantly reduced the Kappa number (P < 0.05) with low consumption of chlorine dioxide alone.     

Characterization and constitutive expression of a novel endo-1,4-β-d-xylanohydrolase from Aspergillus niger in Pichia pastoris

A putative endo-1,4-β-d-xylanohydrolase gene xyl10 from Aspergillus niger, encoding a 308-residue mature xylanase belonging to glycosyl hydrolase family 10, was constitutively expressed in Pichia pastoris. The recombinant Xyl10 exhibited optimal activity at pH 5.0 and 60 °C with more than 50 % of the maximum activity from 40 to 70 °C. It retained more than 90 % of the original activity after incubation at 60 °C (pH 5.0) for 30 min and more than 74 % after incubation at pH 3.0–13.0 for 2 h (25 °C). The specific activity, K _m and V _max values for purified Xyl10 were, respectively, 3.2 × 10³ U mg^?1, 3.6 mg ml^?1 and 5.4 × 10³ μmol min^?1 mg^?1 towards beechwood xylan. The enzyme degraded xylan to a series of xylooligosaccharides and xylose. The recombinant enzyme with these properties has the potential for various industrial applications.     

Characterization of the biochemical properties of recombinant Xyn10C from a marine bacterium, <Emphasis Type="Italic">Saccharophagus degradans</Emphasis> 2-40

Endo-1,4-β-xylanases are mostly classified into glycoside hydrolase (GH) family 10 or 11. In this study, we examined the catalytic functions of a recombinant endo-1,4-β-xylanase belonging to GH10 (Xyn10C) from a marine bacterium, Saccharophagus degradans 2-40. Optimal activity of this enzyme was evident at 30 °C and pH 7.0, but activity remained even at low temperatures, indicating its adaptation to cold. With respect to other xylanases known to be active in cold temperatures, Xyn10C is unique in that it showed maximal activity in the presence of 2 M of NaCl. The action patterns of recombinant Xyn10C on xylans from hardwood and softwood differed in part, but the enzyme hydrolyzed polysaccharidic substrates primarily to xylobiose and xylotriose through xylo-oligosaccharides, releasing a small amount of xylose. The K _m and V _max values on birchwood xylan were 10.4 mg mL^?1 and 253 µmol mg^?1 min^?1, respectively. The efficient catalytic function of Xyn10C on short-length xylo-oligosaccharide chains was similar to the typical function of other known GH10 xylanases.     

A novel cold-active xylanase from the cellulolytic myxobacterium Sorangium cellulosum So9733-1: gene cloning, expression, and enzymatic characterization

The cellulolytic myxobacterium Sorangium cellulosum is able to efficiently degrade many kinds of polysaccharides, but none of the enzymes involved have been characterized. In this paper, a xylanase gene (xynA) was cloned from S. cellulosum So9733-1 using thermal asymmetric interlaced PCR. The gene is composed of 1,209 bp and has only 52.27% G + C content, which is much lower than that of most myxobacterial DNA reported (67–72%). Gene xynA encodes a 402 amino acid protein that contains a single catalytic domain belonging to the glycoside hydrolase family 10. The novel xylanase gene, xynA, was expressed in Escherichia coli BL21 (DE3) and the recombinant protein (r-XynA) was purified by Ni-affinity chromatography. The r-XynA had the optimum temperature of 30–35°C and exhibited 33.3% activity at 5°C and 13.7% activity at 0°C. Approximately 80% activity was lost after 20-min pre-incubation at 50°C. These results indicate that r-XynA is a cold-active xylanase with low thermostability. At 30°C, the K _m values of r-XynA on beechwood xylan, birchwood xylan, and oat spelt xylan were 25.77 ± 4.16, 26.52 ± 4.78, and 38.13 ± 5.35 mg/mL, respectively. The purified r-XynA displayed optimum activity at pH 7.0. The activity of r-XynA was enhanced by the presence of Ca²⁺. The r-XynA hydrolyzed beechwood xylan, birchwood xylan, and xylooligosaccharides (xylotriose, xylotetraose, and xylopentose) to produce primarily xylose and xylobiose. To our knowledge, this is the first report on the characterization of a xylanase from S. cellulosum.     

Biochemical characterization of xylanase produced from Streptomyces sp. CS624 using an agro residue substrate

An extracellular and cellulase-free xylanase (EX624) was produced by Streptomyces sp. CS624 using an agricultural residue (wheat bran) as a growth substrate. EX624 was purified from culture supernatant using ammonium sulfate precipitation, ion exchange and gel filtration chromatography. The SDS-PAGE and the zymogram analysis of the purified xylanase indicated molecular mass of 40 kDa. Biochemical characterization of the purified EX624 revealed its highest activity at a temperature of 60 °C and pH 6.0. The xylanase was adequately stable in the pH range 4.5–10.0 and at temperatures ≤50 °C. EX624 displayed enhanced activity in the presence of several metal ions including Fe²⁺, Co²⁺ and Ca²⁺. HPLC results showed that EX624 was not only able to hydrolyze commercially available pure beechwood xylan to xylose, xylobiose and xylotriose, but also abundantly available lignocellulosic agricultural residues in nature such as wheat bran to xylooligosaccharides.     

Xyn11E from Paenibacillus barcinonensis BP-23: a LppX-chaperone-dependent xylanase with potential for upgrading paper pulps

A new xylanase from Paenibacillus barcinonensis BP-23, Xyn11E, has been identified and characterized. Xyn11E has been cloned and heterologously expressed in Escherichia coli. It is a single-domain xylanase belonging to the family 11 of glycosyl hydrolases (GH11) with a predicted molecular weight of 20.652 kDa and an isoelectric point (pI) of 8.7. Substrate specificity, kinetic properties, and mode of action of the purified xylanase were characterized. Xyn11E exhibited high activity toward branched xylans, being beechwood xylan the preferred substrate. The optimum pH and temperature of the purified enzyme were 6.5 and 50 °C, respectively. Catalytic constants were determined on beechwood xylan, on which Xyn11E showed a Km of 12.98 mg/ml and a Vmax of 3,023 U/mg. The enzyme hydrolyzed long xylooligosaccharides, while oligomers shorter than xylotetraose were not degraded. Products released from glucuronoxylans were shorter than those liberated from cereal arabinoxylans. The xylanase was dependent on P. barcinonensis BP-23 LppX for its expression in an active form. Coexpression of Xyn11E with E. coli chaperones could not replace the need of LppX, which seems to act as a specific chaperone for Xyn11E correct folding. Activity of the enzyme on bleached pulps was evaluated. Xyn11E liberated reducing sugars from ECF and TCF pulps from eucalyptus, sisal, and flax, which makes it a good candidate for the enzymatic-assisted production of high-cellulose-content pulps from paper-grade pulps.     

Production, Purification, and Characterization of a Xylooligosaccharides-forming Xylanase from High-butanol-producing Strain Clostridium sp. BOH3

An endo-acting xylanase is isolated from the culture medium of Clostridium sp. BOH3 when xylan, glucose, xylose, or sugarcane bagasse hydrolysate (SBH) is used as a carbon source. Crude xylanase is purified by using an anionic Q-column with a yield of 39 %. The pure xylanase has a molecular weight of 35.8 kDa, and it shows optimal activity at pH 5 and 60 °C. When beechwood xylan is used as a substrate, this xylanase liberates short oligosaccharides (XOS) predominantly, ranging from xylobiose (X2) to xylopentaose (X5). However, no xylose can be detected, suggesting that this is an endo-β-1,4-xylanase. Kinetic study of this xylanase reveals that K _m and V _max are 1.36 mg/ml and 212 μmol/(min. mg protein), respectively. On the basis of amino acid sequence, this enzyme shows homology to xylanase (xynb) from Clostridium acetobutylicum ATCC 824, but this enzyme has several distinctive characteristics. For example, its activity can be enhanced with the addition of divalent metal ions, and it produces XOS exclusively when xylan is used as a substrate. These unique characteristics suggest that this is a new enzyme.     

Characterization of a neutral recombinant xylanase from <Emphasis Type="Italic">Thermoactinospora rubra</Emphasis> YIM 77501<Superscript>T</Superscript>

A xylanase gene (TrXyn10) from Thermoactinospora rubra YIM 77501^T was cloned and expressed in Escherichia coli. The amino acid sequence displayed 78% homology with Microbispora mesophila xylanase (WP_062413927.1). The recombinant xylanase (TrXyn10), with MW 46.1 kDa, could hydrolyse beechwood, birchwood and oatspelt xylan. Based on the sequence, enzymatic properties and tertiary structure of the protein, TrXyn10 belongs to glycoside hydrolase family 10 (GH10). The optimal pH and temperature for the recombinant enzyme were determined to be 7.0 and 55 °C, respectively. TrXyn10 was stable over a wide pH range, and it retained more than 45% of the total activity at pH 6.0–12.0 for 12 h. In addition, the activity was greatly promoted, by approximately 200% of the initial activity, after incubation at pH 6.0 and 7.0 for 12 h. Based on enzymatic properties and product analysis, we showed that TrXyn10 is a neutral endoxylanase.     

Bifunctional recombinant cellulase–xylanase (rBhcell-xyl) from the polyextremophilic bacterium <Emphasis Type="Italic">Bacillus halodurans</Emphasis> TSLV1 and its utility in valorization of renewable agro-residues

The thermostable bifunctional CMCase and xylanase encoding gene (rBhcell-xyl) from Bacillus halodurans TSLV1 has been expressed in Escherichia coli. The recombinant E. coli produced rBhcell-xyl (CMCase 2272 and 910 U L^?1 xylanase). The rBhcell-xyl is a ~62-kDa monomeric protein with temperature and pH optima of 60 °C and 6.0 with T_1/2 of 7.0 and 3.5 h at 80 °C for CMCase and xylanase, respectively. The apparent K _m values (CMC and Birchwood xylan) are 3.8 and 3.2 mg mL^?1. The catalytic efficiency (k _cat/K _m ) values of xylanase and CMCase are 657 and 171 mL mg^?1 min^?1, respectively. End-product analysis confirmed that rBhcell-xyl is a unique endo-acting enzyme with exoglucanase activity. The rBhcell-xyl is a GH5 family enzyme possessing single catalytic module and carbohydrate binding module. The action of rBhcell-xyl on corn cobs and wheat bran liberated reducing sugars, which can be fermented to bioethanol and fine biochemicals.     

Study of the intracellular xylanolytic activity of the phytopathogenic fungus Sporisorium reilianum

The present study demonstrates that Sporisorium reilianum, a phytopathogenic fungus of corn, produces intracellular xylanolytic activity during submerged fermentation. Production reached its highest levels in a medium containing glucose, corn hemicellulose and yeast extract. An intracellular xylanase was purified by a process that included precipitation with ammonium sulfate, ion exchange chromatography and gel filtration. Optimal pH and temperature values were 5.0 and 60 °C, respectively. The enzyme showed activity through a broad pH range. The molecular weights of pure xylanase were 36 and 37 kDa, determined by SDS PAGE and gel filtration, respectively. K_m and V_max were 0.160 mg/mL and 1.564 μmol/min/mg, respectively, on a substrate of birchwood xylan. SDS, EDTA, β-Mercaptoethanol, Tween 80, Triton and Mn²⁺ and Ca²⁺ strongly inhibited activity. The purified enzyme hydrolyzed xylan, releasing xylotriose and xylobiose. Sequence protein analysis showed 95% similarity with the theoretical protein encoded by the sr14403 gene of S. reilianum, which encodes a putative endo-β-1,4-xylanase. The enzyme is an isoform of the extracellular xylanase SRXL1 of this basidiomycete.     

Molecular cloning and characterization of the novel acidic xylanase XYLD from Bispora sp. MEY-1 that is homologous to family 30 glycosyl hydrolases

We cloned and sequenced a xylanase gene named xylD from the acidophilic fungus Bispora sp. MEY-1 and expressed the gene in Pichia pastoris. The 1,422-bp full-length complementary DNA fragment encoded a 457-amino acid xylanase with a calculated molecular mass of 49.8 kDa. The mature protein of XYLD showed high sequence similarity to both glycosyl hydrolase (GH) families 5 and 30 but was more homologous to members of GH 30 based on phylogenetic analysis. XYLD shared the highest identity (49.9%) with a putative endo-1,6-β-d-glucanase from Talaromyces stipitatus and exhibited 21.1% identity and 34.3% similarity to the well-characterized GH family 5 xylanase from Erwinia chrysanthemi. Purified recombinant XYLD showed maximal activity at pH 3.0 and 60 °C, maintained more than 60% of maximal activity when assayed at pH 1.5–4.0, and had good thermal stability at 60 °C and remained stable at pH 1.0–6.0. The enzyme activity was enhanced in the presence of Ni²⁺ and β-mercaptoethanol and inhibited by some metal irons (Hg²⁺, Cu²⁺, Pb²⁺, Mn²⁺, Li⁺, and Fe³⁺) and sodium dodecyl sulfate. The specific activity of XYLD for beechwood xylan, birchwood xylan, 4-O-methyl-d-glucuronoxylan, and oat spelt xylan was 2,463, 2,144, 2,020, and 1,429 U mg⁻¹, respectively. The apparent K _m and V _max values for beechwood xylan were 5.6 mg ml⁻¹ and 3,622 μmol min⁻¹ mg⁻¹, respectively. The hydrolysis products of different xylans were mainly xylose and xylobiose.     

A xylanase from <Emphasis Type="Italic">Streptomyces sp.</Emphasis> FA1: heterologous expression,characterization, and its application in Chinese steamed bread

Xylanases (EC 3.2.1.8) are hydrolytic enzymes that have found widespread application in the food, feed, and paper-pulp industries. Streptomyces sp. FA1 xynA was expressed as a secreted protein in Pichia pastoris, and the xylanase was applied to the production of Chinese steamed bread for the first time. The optimal pH and the optimal temperature of XynA were 5.5 and 60 °C, respectively. Using beechwood as substrate, the K _m and V _max were 2.408 mg mL^?1 and 299.3 µmol min^?1 mg^?1, respectively. Under optimal conditions, a 3.6-L bioreactor produced 1374 U mL^?1 of XynA activity at a protein concentration of 6.3 g L^?1 after 132 h of fermentation. Use of recombinant XynA led to a greater increase in the specific volume of the CSB than could be achieved using commercial xylanase under optimal conditions. This study provides the basis for the application of the enzyme in the baking industry.     

Cloning,expression and characterization of a novel cold-active and halophilic xylanase from Zunongwangia profunda

A new xylanase gene (xynA) from the marine microorganism Zunongwangia profunda was identified to encode 374 amino acid residues. Its product (XynA) showed the highest identity (42.78 %) with a xylanase from Bacillus sp. SN5 among the characterized xylanases. XynA exhibited the highest activity at pH 6.5 and 30 °C, retaining 23 and 38 % of the optimal activity at 0 and 5 °C, respectively. XynA was not only cold active, but also halophilic, and both its activity and thermostability could be significantly increased by NaCl, showing the highest activity (180 % of the activity) at 3 M NaCl and retaining nearly 100 % activity at 5 M NaCl, compared to the absence of NaCl. In the presence of 3 M NaCl, the k _cat/K _m value of XynA exhibited a 3.41-fold increase for beechwood xylan compared to no added NaCl, and the residual activity of XynA increased from 23 % (no added NaCl) to 58 % after 1 h incubation at 45 °C. This may be the first report concerning a cold-adapted xylanase from a non-halophilic species that displays the highest activity at a NaCl concentration range from 3 to 5 M. The features of cold activity and salt tolerance suggest the potential application of XynA in the food industry and bioethanol production from marine seaweeds.     

A thermo-halo-tolerant and proteinase-resistant endoxylanase from Bacillus sp. HJ14

A glycosyl hydrolase family 10 endoxylanase from Bacillus sp. HJ14 was grouped in a separated cluster with another six Bacillus endoxylanases which have not been characterized. These Bacillus endoxylanases showed less than 52 % amino acid sequence identity with other endoxylanases and far distance with endoxylanases from most microorganisms. Signal peptide was not detected in the endoxylanase. The endoxylanase was expressed in Escherichia coli BL21 (DE3), and the purified recombinant enzyme (rXynAHJ14) was characterized. rXynAHJ14 was apparent optimal at 62.5 °C and pH 6.5 and retained more than 55 % of the maximum activity when assayed at 40–75 °C, 23 % at 20 °C, 16 % at 85 °C, and even 8 % at 0 °C. Half-lives of the enzyme were more than 60 min, approximately 25 and 4 min at 70, 75, and 80 °C, respectively. The enzyme exhibited more than 62 % xylanase activity and stability at the concentration of 3–30 % (w/v) NaCl. No xylanase activity was lost after incubation of the purified rXynAHJ14 with trypsin and proteinase K at 37 °C for 60 min. Different components of oligosaccharides were detected in the time-course hydrolysis of beechwood xylan by the enzyme. During the simulated intestinal digestion phase in vitro, 11.5–19.0, 15.3–19.0, 21.9–27.7, and 28.2–31.2 μmol/mL reducing sugar were released by the purified rXynAHJ14 from soybean meal, wheat bran, beechwood xylan, and rapeseed meal, respectively. The endoxylanase might be an alternative for potential applications in the processing of sea food and saline food and in aquaculture as agastric fish feed additive.