scholarly journals Two-Step Saccharification of the Xylan Portion of Sugarcane Waste by Recombinant Xylanolytic Enzymes for Enhanced Xylose Production

ACS Omega ◽  
2021 ◽  
Author(s):  
Abhijeet Thakur ◽  
Aakash Sharma ◽  
Kaustubh Chandrakant Khaire ◽  
Vijayanand Suryakant Moholkar ◽  
Puneet Pathak ◽  
...  
Keyword(s):  
Xylose Production ◽  
Xylanolytic Enzymes

XYLANASE, AN ENVIRONMENTALLY FRIENDLY BLEACHING AGENT FOR PULP AND PAPER: Characterization And Stabilization Study Of Bacillus licheniformis I-5 CRUDE Xylanase

2018 ◽  
Vol 7 (3) ◽  
Author(s):  
Budiasih Wahyuntari., dkk
Keyword(s):  
Thermal Stability ◽  
Bacillus Licheniformis ◽  
Hot Spring ◽  
Sodium Dodecyl ◽  
Luria Broth ◽  
Crude Enzyme ◽  
Half Time ◽  
Triton X100 ◽  
Sds Page ◽  
Xylanolytic Enzymes

Isolate I-5 was isolated from Ciseeng hot spring, West Java and was identified as Bacillus licheniformis I-5. The isolate produces extracellular xylanolytic enzymes on Oatspelt containing Luria broth agar medium. Optimal activity of the crude enzyme was  observed at 50ºC and pH 7. The effect of sodium dodecyl sulphate, b-mercaptoethanol and Triton-X100 were observed. Incubating the crude enzyme in 1.5% SDS and 1.5% b-mercaptoethanol at 50oC for 90 minutes then adding Triton-X100 at final concentration of 3.5% for 45 minutes only reduced 5.75% of the initial enzyme activity. SDS/PAGE and zymogram analysis showed that at least two xylanolytic enzymes presence in the crude enzyme. The molecular weight of the enzyme was estimated about 127 and 20kD. The enzyme hydrolysed xylan into xylobiose, xylotriose and other longer xylooligosaccharides. Thermal stability of the crude enzyme was observed at 50, 60, and 70oC and pH 7 and 8. The results showed that the half time of the crude enzyme incubated at 50, 60, and 70oC pH 7 was 2 hours 55 minutes; 2 hours 33 minutes and 1 hour 15 minutes respectively. The half time at 50, 60 and 70oC, pH 8 was 2 hours 48 minutes; 1 hour 22 minutes and 1 hour 9 minutes respectively.keywords: Xilanase, Bacillus licheniformis I-5, thermal stability

scholarly journals Xylose production and the associated integration for biocoal production

2020 ◽  
pp. 100073
Author(s):  
Jagannadh Satyavolu ◽  
Jogi Ganesh Dattatreya Tadimeti ◽  
Rajeeva Thilakaratne
Keyword(s):  
Xylose Production

Purification and Properties of a Xylan-Binding Endoxylanase from Alkaliphilic Bacillus sp. Strain K-1

1999 ◽  
Vol 65 (2) ◽  
pp. 694-697 ◽  
Author(s):  
Khanok Ratanakhanokchai ◽  
Khin Lay Kyu ◽  
Morakot Tanticharoen
Keyword(s):  
Xylanase Activity ◽  
Crystalline Cellulose ◽  
Acetyl Esterase ◽  
Affinity Adsorption ◽  
Purification And Properties ◽  
Optimum Ph ◽  
Alkaliphilic Bacillus ◽  
Alkaliphilic Bacterium ◽  
Adsorption Desorption ◽  
Xylanolytic Enzymes

ABSTRACT An alkaliphilic bacterium, Bacillus sp. strain K-1, produces extracellular xylanolytic enzymes such as xylanases, β-xylosidase, arabinofuranosidase, and acetyl esterase when grown in xylan medium. One of the extracellular xylanases that is stable in an alkaline state was purified to homogeneity by affinity adsorption-desorption on insoluble xylan. The enzyme bound to insoluble xylan but not to crystalline cellulose. The molecular mass of the purified xylan-binding xylanase was estimated to be approximately 23 kDa. The enzyme was stable at alkaline pHs up to 12. The optimum temperature and optimum pH of the enzyme activity were 60°C and 5.5, respectively. Metal ions such as Fe2+, Ca2+, and Mg2+ greatly increased the xylanase activity, whereas Mn2+ strongly inhibited it. We also demonstrated that the enzyme could hydrolyze the raw lignocellulosic substances effectively. The enzymatic products of xylan hydrolysis were a series of short-chain xylooligosaccharides, indicating that the enzyme was an endoxylanase.

scholarly journals Optimization of Xylose Production from Sugarcane Trash by Microwave-Maleic Acid Hydrolysis

REAKTOR ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 81-88
Author(s):  
Euis Hermiati ◽  
Maulida Oktaviani ◽  
Riksfardini Annisa Ermawar ◽  
Raden Permana Budi Laksana ◽  
Lutfi Nia Kholida ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Acid Hydrolysis ◽  
Response Surface ◽  
Acid Concentration ◽  
Maleic Acid ◽  
Sugar Alcohol ◽  
Quadratic Regression ◽  
Microwave Assisted ◽  
Concentration Time ◽  
Xylose Production

Sugarcane trash contains significant amount of xylan that could be hydrolysed to xylose. The xylose could be further fermented to produce xylitol, a sugar alcohol that has low calories and does not cause carries of teeth. In this study we optimized the production of xylose from sugarcane trash by microwave-assisted maleic acid hydrolysis using response surface methodology (RSM). The factors optimized were acid concentration, time, and temperature. The xylose yield based on the weight of initial biomass was determined and it served as a response variable. Results show that acid concentration and interaction between time and temperature had significant effect on xylose yield. The quadratic regression model generated from the optimization was fit and can be used to predict the xylose yield after hydrolysis with various combinations of acid concentration, time, and temperature. The optimum condition for xylose production from sugarcane trash was using maleic acid of 1.52%, and heating at 176 °C for 6.8 min. At this condition the yield of xylose was 24.3% per initial biomass or 0.243 g/ g biomass.Keywords: maleic acid; microwave heating; response surface methodology; sugarcane trash, xylose

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.

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