title: Characterization of a novel xylanase from Armillaria gemina and its immobilization onto SiO2 nanoparticles.
abstract: Enhanced catalytic activities of different lignocellulases were obtained from Armillaria gemina under statistically optimized parameters using a jar fermenter. This strain showed maximum xylanase, endoglucanase, cellobiohydrolase, and β-glucosidase activities of 1,270, 146, 34, and 15 U mL(-1), respectively. Purified A. gemina xylanase (AgXyl) has the highest catalytic efficiency (k                 (cat)/K                 (m) = 1,440 mg mL(-1) s(-1)) ever reported for any fungal xylanase, highlighting the significance of the current study. We covalently immobilized the crude xylanase preparation onto functionalized silicon oxide nanoparticles, achieving 117 % immobilization efficiency. Further immobilization caused a shift in the optimal pH and temperature, along with a fourfold improvement in the half-life of crude AgXyl. Immobilized AgXyl gave 37.8 % higher production of xylooligosaccharides compared to free enzyme. After 17 cycles, the immobilized enzyme retained 92 % of the original activity, demonstrating its potential for the synthesis of xylooligosaccharides in industrial applications.
authors.affiliation: Department of Chemical Engineering, Konkuk University, 1 Hwayang-Dong, Gwangjin-Gu, Seoul, 143-701, Republic of Korea.
authors.forename: Saurabh Sudha
authors.initials: SS
authors.lastname: Dhiman
authors.forename: Dayanand
authors.initials: D
authors.lastname: Kalyani
authors.forename: Sujit Sadashiv
authors.initials: SS
authors.lastname: Jagtap
authors.forename: Jung-Rim
authors.initials: JR
authors.lastname: Haw
authors.forename: Yun Chan
authors.initials: YC
authors.lastname: Kang
authors.forename: Jung-Kul
authors.initials: JK
authors.lastname: Lee
mesh_terms: D055392:Armillaria / Q000201:enzymology* / Q000235:genetics; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D043364:Endo-1,4-beta Xylanases / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D004800:Enzymes, Immobilized / Q000378:metabolism*; D008969:Molecular Sequence Data; D053758:Nanoparticles / Q000737:chemistry; D009844:Oligosaccharides / Q000378:metabolism; D017422:Sequence Analysis, DNA; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D004271:DNA, Fungal; D004800:Enzymes, Immobilized; D009844:Oligosaccharides; D012822:Silicon Dioxide; D043364:Endo-1,4-beta Xylanases