scholarly journals Prebiotic effect of xylooligosaccharides produced from birchwood xylan by a novel fungal GH11 xylanase

2017 ◽  
Vol 232 ◽  
pp. 105-113 ◽  
Author(s):  
Manuel Nieto-Domínguez ◽  
Laura I. de Eugenio ◽  
María J. York-Durán ◽  
Barbara Rodríguez-Colinas ◽  
Francisco J. Plou ◽  
...  
Keyword(s):  
Birchwood Xylan

scholarly journals Exploiting xylan as sugar donor for the synthesis of an antiproliferative xyloside using an enzyme cascade

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Manuel Nieto-Domínguez ◽  
José Alberto Martínez-Fernández ◽  
Beatriz Fernández de Toro ◽  
Juan A. Méndez-Líter ◽  
Francisco Javier Cañada ◽  
...  
Keyword(s):  
Chemical Synthesis ◽  
Biomass Conversion ◽  
Value Added ◽  
Cost Effective ◽  
Raw Material ◽  
Birchwood Xylan ◽  
Enzyme Cascade ◽  
Antiproliferative Agent ◽  
Xylanolytic Enzymes ◽  
Value Added Products

Abstract Background Currently, industrial societies are seeking for green alternatives to conventional chemical synthesis. This demand has merged with the efforts to convert lignocellulosic biomass into value-added products. In this context, xylan, as one of main components of lignocellulose, has emerged as a raw material with high potential for advancing towards a sustainable economy. Results In this study, the recombinant endoxylanase rXynM from the ascomycete Talaromyces amestolkiae has been heterologously expressed in Pichia pastoris and used as one of the catalysts of an enzyme cascade developed to synthesize the antiproliferative 2-(6-hydroxynaphthyl) β-d-xylopyranoside, by transglycosylation of 2,6-dihydroxynaphthalene. The approach combines the use of two fungal xylanolytic enzymes, rXynM and the β-xylosidase rBxTW1 from the same fungus, with the cost-effective substrate xylan. The reaction conditions for the cascade were optimized by a Central Composite Design. Maximal productions of 0.59 and 0.38 g/L were reached using beechwood xylan and birchwood xylan, respectively. For comparison, xylans from other sources were tested in the same reaction, suggesting that a specific optimization is required for each xylan variety. The results obtained using this enzyme cascade and xylan were similar or better to those previously reported for a single catalyst and xylobiose, an expensive sugar donor. Conclusions Beechwood and birchwood xylan, two polysaccharides easily available from biomass, were used in a novel enzyme cascade to synthetize an antiproliferative agent. The approach represents a green alternative to the conventional chemical synthesis of 2-(6-hydroxynaphthyl) β-d-xylopyranoside using a cost-effective substrate. The work highlights the role of xylan as a raw material for producing value-added products and the potential of fungal xylanolytic enzymes in the biomass conversion.

Characterization of cellulase-free xylanases from the newly isolated Bacillus sp. strain BP-23

1993 ◽  
Vol 39 (12) ◽  
pp. 1162-1166 ◽  
Author(s):  
A. Blanco ◽  
F. I. J. Pastor
Keyword(s):  
Polyacrylamide Gel Electrophoresis ◽  
Xylanase Activity ◽  
Hydrolytic Activity ◽  
Bacillus Sp ◽  
Birchwood Xylan ◽  
Xylanase Production ◽  
Ph Values ◽  
Wide Range ◽  
Molecular Masses

A Bacillus strain with xylanase activity has been isolated. Maximum xylanase production was obtained when the strain was cultured in media supplemented with birchwood xylan or rice straw; production was repressed by glucose and xylose. The optimal temperature and pH for xylanase activity were 45–50 °C and 5.5–7.5, respectively. Crude xylanase was highly stable at a wide range of pH values, retaining 100% of the activity after 24 h of incubation at 37 °C in buffer at pH 10.0. Analysis by polyacrylamide gel electrophoresis and zymogram techniques showed four xylanase activity bands with apparent molecular masses of 32, 48, 61, and 66 kDa. The most active of them (molecular mass 32 kDa) apparently corresponded to a xylanase with an isoelectric point (pI) of 9.3 in isoelectrofocusing gels developed as zymograms. Four other bands with xylanase activity were detected at pIs of 7.7, 5.6, 5.0, and 4.5. Analysis for carboxymethylcellulase activity revealed that only the band of 48 kDa and the band with a pI of 7.7 showed hydrolytic activity against the cellulosic substrate.Key words: Bacillus sp., xylanase, isolation.

Process development and simulation of glucose isomerase production from birchwood xylan by a Streptomycetes fusant

1998 ◽  
Vol 1 (2) ◽  
pp. 159-168 ◽  
Author(s):  
Siriluk Teeradakorn ◽  
Michimasa Kishimoto ◽  
Tatsuji Seki ◽  
Pairoh Pinphanichakarn ◽  
Toshiomi Yoshida
Keyword(s):  
Process Development ◽  
Glucose Isomerase ◽  
Birchwood Xylan

Potential application of cellulase and hemicellulase assay techniques for assessing the forage quality and performance of rumen micro-organisms

1998 ◽  
Vol 22 ◽  
pp. 290-293
Author(s):  
M. K. Bhat
Keyword(s):  
Cell Wall ◽  
Filter Paper ◽  
Plant Cell Wall ◽  
Birchwood Xylan ◽  
Efficient Utilization ◽  
Potential Applications ◽  
Assay Methods ◽  
Carl Roth Gmbh ◽  
And Performance ◽  
Micro Organisms

Cellulose and hemicellulose are the major structural polysaccharides of plant cell wall. The efficient utilization of these polysaccharides by ruminants is often restricted by the presence of lignin. Cellulose and hemicellulose are hydrolysed by a group of enzymes called cellulases and hemicellulases. The present paper describes the cellulase and hemicellulase assay methods and their potential applications.Carboxymethyl (CM)-cellulose, Avicel, cellobiose, xylobiose, p-nitrophenyl-p β-D-glucoside (pNPG), p-nitrophenyl-β-D-cellobioside (pNPC), p-nitrophenyl-β-D-xyloside (pNPX) and p-nitrophenyl- α-L-arabinofuranoside (pNPAf) were from Sigma. Birchwood xylan and filter paper are from Carl Roth GmbH and Co., Germany and Whatman International Ltd, UK, respectively. H3P04-Swollen cellulose and 4-O-methyl-α-D-glucuronyl-xylotriose (mGpA-Xyl3) were prepared as described (Wood, 1988; Khandkeet al., 1989a).

scholarly journals An Innovative Biocatalyst for Continuous 2G Ethanol Production from Xylo-Oligomers by Saccharomyces cerevisiae through Simultaneous Hydrolysis, Isomerization, and Fermentation (SHIF)

Catalysts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 225 ◽  
Author(s):  
Thais Milessi-Esteves ◽  
Felipe Corradini ◽  
Willian Kopp ◽  
Teresa Zangirolami ◽  
Paulo Tardioli ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ethanol Production ◽  
Ethanol Yield ◽  
Xylose Isomerase ◽  
Ethanol Productivity ◽  
Spherical Particles ◽  
Birchwood Xylan ◽  
Alginate Gel ◽  
Industrial Implementation ◽  
Ca Alginate

Many approaches have been considered aimed at ethanol production from the hemicellulosic fraction of biomass. However, the industrial implementation of this process has been hindered by some bottlenecks, one of the most important being the ease of contamination of the bioreactor by bacteria that metabolize xylose. This work focuses on overcoming this problem through the fermentation of xylulose (the xylose isomer) by native Saccharomyces cerevisiae using xylo-oligomers as substrate. A new concept of biocatalyst is proposed, containing xylanases and xylose isomerase (XI) covalently immobilized on chitosan, and co-encapsulated with industrial baker’s yeast in Ca-alginate gel spherical particles. Xylo-oligomers are hydrolyzed, xylose is isomerized, and finally xylulose is fermented to ethanol, all taking place simultaneously, in a process called simultaneous hydrolysis, isomerization, and fermentation (SHIF). Among several tested xylanases, Multifect CX XL A03139 was selected to compose the biocatalyst bead. Influences of pH, Ca2+, and Mg2+ concentrations on the isomerization step were assessed. Experiments of SHIF using birchwood xylan resulted in an ethanol yield of 0.39 g/g, (76% of the theoretical), selectivity of 3.12 gethanol/gxylitol, and ethanol productivity of 0.26 g/L/h.

scholarly journals Isolation, Purification, and Characterization of Xylanase Produced by a New Species ofBacillusin Solid State Fermentation

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Rajashri D. Kamble ◽  
Anandrao R. Jadhav
Keyword(s):  
New Species ◽  
Solid State ◽  
Solid State Fermentation ◽  
Exchange Chromatography ◽  
Optimum Temperature ◽  
Birchwood Xylan ◽  
Purification And Characterization ◽  
Application Potential ◽  
A New Species

A thermoalkalophilic new species ofBacillus, similar toBacillus arseniciselenatisDSM 15340, produced extracellular xylanase under solid state fermentation when wheat bran is used as carbon source. The extracellular xylanase was isolated by ammonium sulfate (80%) precipitation and purified using ion exchange chromatography. The molecular weight of xylanase was ~29.8 ;kDa. The optimum temperature and pH for the enzyme activity were 50°C and pH 8.0. The enzyme was active on birchwood xylan and little active onp-nitrophenyl xylopyranoside but not on Avicel, CMC, cellobiose, and starch, showing its absolute substrate specificity. For birchwood xylan, the enzyme gave a Km 5.26 ;mg/mL and Vmax 277.7 ;μmol/min/mg, respectively. In addition, the xylanase was also capable of producing high-quality xylo-oligosaccharides, which indicated its application potential not only in pulp biobleaching processes but also in the nutraceutical industry.

Screening for xylanase and β-xylosidase production from wood-inhabiting Penicillium strains for potential use in biotechnological applications

Holzforschung ◽  
2012 ◽  
Vol 66 (2) ◽  
Author(s):  
Jaejung Lee ◽  
Yeongseon Jang ◽  
Hanbyul Lee ◽  
Sangjoon Lee ◽  
Gyu-Hyeok Kim ◽  
...  
Keyword(s):  
Paper Industry ◽  
Carbon Sources ◽  
Xylanase Activity ◽  
Cellulase Activity ◽  
Pulp And Paper Industry ◽  
Biotechnological Applications ◽  
Birchwood Xylan ◽  
Beechwood Xylan ◽  
Filter Paper Assay ◽  
Potential Use

Abstract Experiments were performed to find potential sources for enzyme production for the pulp and paper industry and for biological ethanol production by screening the cellulase, xylanase and β-xylosidase activities of 36 species of Penicillium isolated from various wood materials in Korea. Rice straw powder (RiceP), birchwood xylan (BirchX), and beechwood xylan (BeechX) were supplied as individual carbon sources for the Penicillium species. All Penicillium species tested in this study showed little cellulase activity, but some species exhibited remarkably high xylanase and β-xylosidase activities, as determined by a filter paper assay. P. oxalicum showed the greatest xylanase activity on RiceP (158.70 U ml-1). On the other hand, P. brevicompactum produced the highest active β-xylosidase on BirchX (6.25 U ml-1).

scholarly journals Influence of some sugars on xylanase production by Aspergillus awamori in solid state fermentation

2002 ◽  
Vol 45 (4) ◽  
pp. 431-437 ◽  
Author(s):  
Judith Liliana Solórzano Lemos ◽  
Nei Pereira Junior
Keyword(s):  
Solid State ◽  
Carbon Source ◽  
Sugar Cane ◽  
Sugar Cane Bagasse ◽  
Aspergillus Awamori ◽  
Birchwood Xylan ◽  
Xylanase Production ◽  
Low Levels ◽  
Xylosidase Activity

Aspergillus awamori showed high extracellular endoxylanase (100 U/ml) and beta-xylosidase activities (3.5 U/ml) when grown on milled sugar cane bagasse as the principal carbon source without treatment. Partial characterization of xylanases showed that the apparent values of Km were 3.12 ± 0.05 mg/ml for endoxylanase (in birchwood xylan) and 0.45 ± 0.05 mM for beta-xylosidase (in p -nitrophenyl beta-D-xylanopiranoside). Corresponding values of Vmax were 6.63 ± 0.02 and 0.078 ± 0.02 mumol/min. Gradual repression of endoxylanase activity was observed when increasing concentrations of glucose and xylose (1, 2, 4, 6 and 8 g of carbohydrate / 4 g of sugar cane bagasse) were added to production media. In contrast, beta-xylosidase activity was stimulated using low levels of carbohydrates (1 g xylose or glucose/ 4 g of sugar cane bagasse).

scholarly journals Identification and Characterization of a Novel, Cold-Adapted d-Xylobiose- and d-Xylose-Releasing Endo-β-1,4-xylanase from an Antarctic Soil Bacterium, Duganella sp. PAMC 27433

Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 680
Author(s):  
Do Young Kim ◽  
Jonghoon Kim ◽  
Yung Mi Lee ◽  
Jong Suk Lee ◽  
Dong-Ha Shin ◽  
...  
Keyword(s):  
Tween 80 ◽  
Maximum Activity ◽  
Soil Bacterium ◽  
Glycoside Hydrolase Family ◽  
Antarctic Soil ◽  
Birchwood Xylan ◽  
Uncultured Bacterium ◽  
Cold Adapted ◽  
Beechwood Xylan ◽  
Key Enzyme

Endo-β-1,4-xylanase is a key enzyme in the degradation of β-1,4-d-xylan polysaccharides through hydrolysis. A glycoside hydrolase family 10 (GH10) endo-β-1,4-xylanase (XylR) from Duganella sp. PAMC 27433, an Antarctic soil bacterium, was identified and functionally characterized. The XylR gene (1122-bp) encoded an acidic protein containing a single catalytic GH10 domain that was 86% identical to that of an uncultured bacterium BLR13 endo-β-1,4-xylanase (ACN58881). The recombinant enzyme (rXylR: 42.0 kDa) showed the highest beechwood xylan-degrading activity at pH 5.5 and 40 °C, and displayed 12% of its maximum activity even at 4 °C. rXylR was not only almost completely inhibited by 5 mM N-bromosuccinimide or metal ions (each 1 mM) including Hg2+, Ca2+, or Cu2+ but also significantly suppressed by 1 mM Ni2+, Zn2+, or Fe2+. However, its enzyme activity was upregulated (>1.4-fold) in the presence of 0.5% Triton X-100 or Tween 80. The specific activities of rXylR toward beechwood xylan, birchwood xylan, oat spelts xylan, and p-nitrophenyl-β-d-cellobioside were 274.7, 103.2, 35.6, and 365.1 U/mg, respectively. Enzymatic hydrolysis of birchwood xylan and d-xylooligosaccharides yielded d-xylose and d-xylobiose as the end products. The results of the present study suggest that rXylR is a novel cold-adapted d-xylobiose- and d-xylose-releasing endo-β-1,4-xylanase.

Improving the catalytic efficiency of thermostable Geobacillus stearothermophilus xylanase XT6 by single-amino acid substitution

2019 ◽  
Vol 167 (2) ◽  
pp. 203-215
Author(s):  
Rasha A M Azouz ◽  
Usama M Hegazy ◽  
Mahmoud M Said ◽  
Roqaya I Bassuiny ◽  
Ahmed M Salem ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Substitution ◽  
Catalytic Efficiency ◽  
Maximum Activity ◽  
Single Amino Acid Substitution ◽  
Single Amino Acid ◽  
Sequencing Analysis ◽  
Geobacillus Stearothermophilus ◽  
Birchwood Xylan ◽  
Alkaline Tolerance

Abstract Directed evolution using error-prone polymerase chain reaction was employed in the current study to enhance the catalytic efficiency of a thermostable Geobacillus stearothermophilus xylanase XT6 parent. High-throughput screening identified two variants with enhanced activity. Sequencing analysis revealed the presence of a single-amino acid substitution (P209L or V161L) in each variant. The maximum activity of mutant V161L and P209L was at 85°C and 70°C, respectively. Both mutants exhibited maximum activity at pH 7. The thermal and alkaline tolerance of mutant V161L only were markedly improved. The two mutants were more resistant to ethanol inhibition than the parent. Substrate specificity of the two mutants was shifted from beechwood xylan to birchwood xylan. The potential of the two mutants to hydrolyze rice straw and sugarcane bagasse increased. Both turnover number (kcat) and catalytic efficiency (kcat/kM) increased 12.2- and 5.7-folds for variant P209L and 13- and 6.5-folds for variant V161L, respectively, towards birchwood xylan. Based on the previously published crystal structure of extracellular G. stearothermophilus xylanase XT6, V161L and P209L mutation locate on βα-loops. Conformational changes of the respective loops could potentiate the loop swinging, product release and consequently result in enhancement of the catalytic performance.

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