Enzymatic saccharification of Narlisaray population hemp hurd using recombinant β-xylanase from <i>Caldicellulosiruptor acetigenus</i>: A potential approach for biofuel production
BIOMASS & BIOENERGY, cilt.217, 2027 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 217
- Basım Tarihi: 2027
- Doi Numarası: 10.1016/j.biombioe.2026.110014
- Dergi Adı: BIOMASS & BIOENERGY
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Compendex, Environment Index, Geobase, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Bursa Uludağ Üniversitesi Adresli: Evet
Özet
The J3-xylanase gene obtained from the thermophilic bacterium Caldicellulosiruptor acetigenus was cloned, expressed, purified, and characterized in Escherichia coli BL21 (DE3) via the pET-28a(+) vector for potential biofuel applications. Heat treatment followed by immobilized metal affinity chromatography efficiently purified the recombinant J3-xylanase. SDS-PAGE revealed a molecular weight of approximately 45 kDa. Characterization studies showed high enzyme stability at pH 6.0-7.0 and 65-80 degrees C. 1 mM Ca2+ and Mg2+ increased residual activity, while Cu2+, Fe2+, and Zn2+ showed inhibitory effects. Furthermore, the enzyme showed strong stability in 10% ethanol and methanol. The enzyme exhibited a Km of 3.75 mg mL(-1) and a Vmax of 325.31 mu mol min(-1) mg(-1) toward beechwood xylan, indicating favorable substrate affinity and catalytic efficiency. For subsequent biorecycling, industrial hemp hurds from the Narlisaray region was subjected to alkaline pretreatment (2% NaOH, 100 degrees C) for 30, 60, and 90 min. Structural and chemical changes in the raw and pretreated biomass were confirmed by SEM and FTIR analyses, showing increased porosity and partial removal of the lignin barrier. Saccharification experiments with 146 U of purified J3-xylanase showed a time-dependent increase in reducing sugar release. Maximum saccharification yield (24.51%) and sugar concentration (1.362 +/- 0.02 mg mL(-1)) were obtained after 72 h of enzymatic hydrolysis using 90 min pretreated hemp hurd. These findings highlight the potential of the recombinant thermostable J3-xylanase as a biocatalyst for efficient saccharification of alkalipretreated industrial hemp biomass and its application in sustainable biorefinery processes.