• Microbiology and Biotechnology Letters
• /
• v.44 no.4
• /
• pp.512-521
• /
• 2016

A bacterial strain was isolated from a soil sample collected on Jeju Island, Korea. The strain, designated WJ-2, exhibited a high xylanase activity, whereas cellulase activity was not detected. The 16S rRNA gene sequence of WJ-2 was highly similar to type strains of the genus Streptomyces. A neighbor-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain WJ-2 is phylogenetically related to Streptomyces atrovirens. Furthermore, DNA-DNA hybridization analysis confirmed that strain WJ-2 is a novel subspecies of Streptomyces atrovirens. The genomic DNA G+C content was 73.98 mol% and the major fatty acid present was anteiso-C15:0 (36.19%). The growth and xylanase production of strain WJ-2 were significantly enhanced by using soytone and xylan as nitrogen and carbon sources, respectively. Crude enzyme preparations from the culture broth of strain WJ-2 exhibited maximal total xylanase activities at pH 7.0 and $55^{\circ}C$. Thin-layer chromatography analysis revealed that the crude enzyme degrades beechwood xylan to yield xylobiose and xylotriose as the principal hydrolyzed end products.

• Microbiology and Biotechnology Letters
• /
• v.45 no.2
• /
• pp.155-161
• /
• 2017

A gene coding for the xylanase predicted from the partial genomic sequence of Paenibacillus woosongensis was cloned by PCR amplification and sequenced completely. This xylanase gene, designated xyn11B, consisted of 1,071 nucleotides encoding a polypeptide of 356 amino acid residues. Based on the deduced amino acid sequence, Xyn11B was identified to be a modular enzyme, including a single carbohydrate-binding module besides the catalytic domain, and was highly homologous to xylanases belonging to glycosyl hydrolase family 11. The SignalP4.1 server predicted a stretch of 26 residues in the N-terminus to be the signal peptide. Using DEAE-Sepharose and Phenyl-Sepharose column chromatography, Xyn11B was partially purified from the cell-free extract of recombinant Escherichia coli carrying a copy of the P. woosongensis xyn11B gene. The partially purified Xyn11B protein showed maximal activity at $50^{\circ}C$ and pH 6.5. The enzyme was more active on arabinoxylan than on oat spelt xylan and birchwood xylan, whereas it did not exhibit activity towards carboxymethylcellulose, mannan, and para-nitrophenyl-${\beta}$-xylopyranoside. The activity of Xyn11B was slightly increased by $Ca^{2+}$ and $Mg^{2+}$, but was significantly inhibited by $Cu^{2+}$, $Ni^{2+}$, $Fe^{3+}$, and $Mn^{2+}$, and completely inhibited by SDS.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.1
• /
• pp.9-19
• /
• 2016

Xylanases sourced from different bacteria have significantly different enzymatic properties. Therefore, studying xylanases from different bacteria is important to their applications in different fields. A potential xylanase degradation gene in Massilia was recently discovered through genomic sequencing. However, its xylanase activity remains unexplored. This paper is the first to report a xylanase (XynRBM26) belonging to the glycosyl hydrolase family (GH10) from the genus Massilia. The gene encodes a 383-residue polypeptide (XynRBM26) with the highest identity of 62% with the endoxylanase from uncultured bacterium BLR13. The XynRBM26 expressed in Escherichia coli BL21 is a monomer with a molecular mass of 45.0 kDa. According to enzymatic characteristic analysis, pH 5.5 is the most appropriate for XynRBM26, which could maintain more than 90% activity between pH 5.0 and 8.0. Moreover, XynRBM26 is stable at 37℃ and could maintain at least 96% activity after being placed at 37℃ for 1 h. This paper is the first to report that GH10 xylanase in an animal gastrointestinal tract (GIT) has salt tolerance, which could maintain 86% activity in 5 M NaCl. Under the optimum conditions, K_m, V_max, and k_cat of XynRBM26 to beechwood xylan are 9.49 mg/ml, 65.79 μmol/min/mg, and 47.34 /sec, respectively. Considering that XynRBM26 comes from an animal GIT, this xylanase has potential application in feedstuff. Moreover, XynRBM26 is applicable to high-salt food and seafood processing, as well as other high-salt environmental biotechnological fields, because of its high catalytic activity in high-concentration NaCl.

• Asian-Australasian Journal of Animal Sciences
• /
• v.25 no.4
• /
• pp.515-523
• /
• 2012

The objective of this study was to investigate the variability in broiler performance, apparent metabolisable energy (AME) and ileal digestible energy (IDE) between five different maize samples fed with and without xylanase at 16,000 U/kg. Various in vitro characterisations were conducted to determine if any could predict performance or AME. Samples of the maize were harvested in five diverse regions and fed individually in a mash diet as follows (g/kg): test maize 608.3; soya bean meal (SBM) 324.1; poultry fat 25.2; salt 4.6; met 2.6; lys 1.6; thr 0.5; limestone 9.7, dical 18.4; vit/min 5.0; CP 210 and ME (kcal/kg) 3,085. The diets were fed to 720 broilers with 6 replicates, each containing 12 birds per treatment, from 0 to 18 d of age. Maize samples were analysed for starch, protein, crude fibre, fat, protein solubility index (PSI) and vitreousness using near infra red reflectance spectroscopy (NIR). They were also assayed using an in vitro starch digestibility method. The results showed that there was no effect of harvest region on the feed intake (FI), body weight gain (BWG) or feed conversion ratio (FCR) of the broilers over the 18 d period (p = 0.959, 0.926, 0.819 respectively). There was an improvement in all parameters with the addition of xylanase (FI p = 0.011; BWG and FCR p<0.001). There was a significant positive effect of xylanase on IDE, AME, IDE Intake (IDEI) and AME intake (AMEI) (p<0.0001 in all cases). Although there was no significant effect of maize source, there was a strong trend towards variability in IDE (p = 0.066) and AME (p = 0.058). There were no significant correlations (p<0.05) between any proximate or physiochemical values and any performance or AME values. This may suggest that none of those selected were suitable predictors for performance or AME. The broilers performed well according to the breed guidelines, with slightly increased FI, increased BWG and similar FCR prior to the addition of xylanase. When FCR and BWG were analysed with FI as a covariate, xylanase addition remained significant suggesting that the improvement in BWG and FCR was driven by an increase in digestibility and nutrient availability.

• Journal of the Korean Wood Science and Technology
• /
• v.35 no.6
• /
• pp.166-174
• /
• 2007

To know the effect of enzymatic pre-treatment on softwood Kraft pulp, two xylanse-encoding genes, named xynl and xynll were isolated from Thrichoderma ressei. Structural genes of xylanase (XYNI, XYNII) and cellulase (EGIV-CBDII) were isolated from T. ressei and Rumicoccus albus respectively, and expressed in E. coli. bacterial culture. The specific activity of purified recombinant XYNI is higher than XYNII. The brightness of XYNI treated softwood Kraft pulp increased to 29.9%. On further sequential treatment with EGIV-CBDII and XYNI the brightness of softwood Kraft pulp were improved to 9.1 and 73% respectively. As expected the Kappa number of softwood Kraft pulp also decreased 8.1, 4.6 and 3.2% respectively. Results further indicate that this sequential combination of enzyme treatment has synergic effect for improving bleaching of softwood Kraft pulp.

• Asian-Australasian Journal of Animal Sciences
• /
• v.27 no.7
• /
• pp.946-950
• /
• 2014

Bacillus licheniformis was grown in minimal nutrient medium containing 1% (w/v) of distillers dried grain with soluble (DDGS), palm kernel meal (PKM), wheat bran (WB) or copra meal (CM), and the enzyme activity of endoglucanase, ${\beta}$-glucosidase, xylanase and reducing sugars was measured to investigate a possibility of using cost-effective agricultural residues in producing cellulolytic and hemicellulolytic enzymes. The CM gave the highest endoglucanase activity of 0.68 units/mL among added substrates at 48 h. CM yielded the highest titres of 0.58 units/ml of ${\beta}$-glucosidase, compared to 0.33, 0.23, and 0.16 units/mL by PKM, WB, and DDGS, respectively, at 72 h. Xylanase production was the highest (0.34 units/mL) when CM was added. The supernatant from fermentation of CM had the highest reducing sugars than other additional substrates at all intervals (0.10, 0.12, 0.10, and 0.11 mg/mL respectively). It is concluded that Bacillus licheniformis is capable of producing multiple cellulo- and hemicellololytic enzymes for bioethanol production using cost-effective agricultural residues, especially CM, as a sole nutrient source.

• Asian-Australasian Journal of Animal Sciences
• /
• v.12 no.5
• /
• pp.752-757
• /
• 1999

Studies were made of digestion of timothy (Pheleum pretense) hay, tall fescue (Festuca elatior) hay, and rice (Oryza sativa) straw in pure cultures of rumen anaerobic fungus, Neocallimastix frontails MCH3. The fungus was inoculated on ground forages (1%, w/v) in an anaerobic medium and incubated at $39^{\circ}C$. Incubation was continued for 24, 48, 72 and 96 h. The losses of dry matter, xylose and glucose of forage during incubation were determined at the end of these incubation periods. Xylose and glucose were considered to be released from xylan and cellulose, respectively. The digested xylan to digested cellulose (X/C) ratios of the substrate were calculated. Xylanase and carboxymethyl cellulose (CMCase) of culture supernatant and residual substrate was measured at the same time. The X/C ratios in the cultures on timothy hay and rice straw were greater than 0.5 in the first 24-h incubation period. The values were smaller than 0.3 in tall fesque. The ratio of xylanase activity to that of CMCase in the first 24-h incubation period correlated well with the traits in X/C ratio. However xylanase activity was still superior to CMCase in the following incubation period (48 to 96 h), although the glucose (designated as cellulose) was more intensively digested than xylose (designated as xylan). The production of these polysaccharidases appeared to correlate with substrate cell-wall sugar composition, xylose to glucose ratios, at the beginning of fast growing period.

• BMB Reports
• /
• v.44 no.10
• /
• pp.653-658
• /
• 2011

Sclerotinia sclerotiorum fungus has three endoxylanases induced by wheat bran. In the first part, a partial xylanase sequence gene (90 bp) was isolated by PCR corresponding to catalytic domains (${\beta}5$ and ${\beta}6$ strands of this protein). The high homology of this sequence with xylanase of Botryotinia fuckeliana has permitted in the second part to amplify the XYN1 gene. Sequence analysis of DNA and cDNA revealed an ORF of 746 bp interrupted by a 65 bp intron, thus encoding a predicted protein of 226 amino acids. The mature enzyme (20.06 kDa), is coded by 188 amino acid (pI 9.26). XYN1 belongs to G/11 glycosyl hydrolases family with a conserved catalytic domain containing $E_{86}$ and $E_{178}$ residues. Bioinformatics analysis revealed that there was no Asn-X-Ser/Thr motif required for N-linked glycosylation in the deduced sequence however, five O-glycosylation sites could intervene in the different folding of xylanses isoforms and in their secretary pathway.

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

• Journal of Microbiology and Biotechnology
• /
• v.22 no.8
• /
• pp.1084-1091
• /
• 2012

Xylooligosaccharides are functional foods mainly produced during the hydrolysis of xylan by physical, chemical, or enzymatic methods. In this study, production of xylobiose was investigated using oil palm empty fruit bunch fiber (OPEFB) as a source material, by chemical and enzymatic methods. Xylanase-specific xylan hydrolysis followed by xylobiose production was observed. Among different xylanases, xylanase from FXY-1 released maximum xylobiose from pretreated OPEFB fiber, and this fungal strain was identified as Aspergillus terreus and subsequently deposited under the accession Number MTCC- 8661. The imperative role of lignin on xylooligosaccharides enzymatic synthesis was exemplified with the notice of xylobiose production only with delignified material. A maximum 262 mg of xylobiose was produced from 1.0 g of pretreated OPEFB fiber using FXY-1 xylanase (6,200 U/ml) at pH 6.0 and $45^{\circ}C$. At optimized environment, the yield of xylobiose was improved to 78.67 g/100 g (based on xylan in the pretreated OPEFB fiber).