Articles
Industrial Crops and Products (09266690)223
The laccase enzyme is considered as a highly effective catalyst with extensive applications in lignin degradation and sustainable energy production from lignocellulosic biomass. This study presents a novel approach for the degradation of phenolic compounds found in the structure of lignocellulosic biomasses by using laccase immobilized on the surface of nanocellulose-functionalized magnetic nanoparticles (Fe3O4@NC@Enz). The synthesis of this nanobiocatalyst was confirmed through various characterization techniques. Under optimal immobilization conditions, incubation time of 8 hours and enzyme concentration of 2 mg/mL, an impressive immobilization yield of 93.26 % and a relative activity of 90.32 % were achieved. The immobilized laccase demonstrated a storage stability of 68.9 % of its initial activity over a 60-day storage period and exhibited superior stability to that of the free enzyme under various pH and temperature conditions. This study investigated the application of Fe3O4@NC@Enz for degrading phenolic compounds, achieving a notable degradation rate of 84.74 % of the total polyphenol content in the lignin structure while retaining 72.4 % of its catalytic activity after 12 reuse cycles. The immobilized laccase was also effective in both delignification and detoxification of corncob, reaching rates of 72 % and 86.69 %, respectively, after 12 hours of incubation. In conclusion, the findings underscore the effectiveness of the Fe3O4@NC@Enz to improve enzyme stability, activity, and reusability, offering a promising approach for the efficient delignification and detoxification of lignocellulosic biomasses. © 2024 The Authors
Biomass and Bioenergy (09619534)200
This study investigates a sequential process using triticale straw (TSW) as a substrate, integrating acetone-butanol-ethanol (ABE) fermentation with in-situ butanol extraction, followed by oleaginous fermentation of the residual medium containing volatile fatty acids (VFAs) to produce single-cell oil (SCO). Using XAD-4 Amberlite adsorbent for in-situ ABE separation, the residual broth was converted to SCO by Cryptococcus aureus. Pretreatment of the straw with either dilute acid (1 % H2SO4) or alkaline (1 % NaOH) was followed by enzymatic hydrolysis using Cellic® CTec2 enzymes, achieving a glucose yield of 85 % at the optimal condition (170 °C, 1 %NaOH). The untreated TSW showed a total sugar concentration of 4.12 g/L after 72 h, with production of 0.68 g/L butanol, 0.17 g/L ethanol, and 0.70 g/L SCO in the subsequent fermentation stage. Pretreatment significantly enhanced ABE production, with dilute acid pretreatment generating 28.0 g/L of total sugars and resulting in 9.0 g/L of solvents in the subsequent ABE fermentation. The highest ABE production (11.82 g/L) was obtained from the alkali-pretreated straw at 170 °C. XAD-4 Amberlite further increased ABE concentration to 12.97 g/L. Optimal biomass and lipid production (9.96 g/L and 3.25 g/L, respectively) were also attained following alkaline pretreatment. These results demonstrate the potential of triticale straw for sustainable butanol and lipid production. © 2025 Elsevier Ltd
Bioresource Technology (09608524)419
Tannin-containing sorghum grains, suitable for acetone-butanol-ethanol (ABE) production by Clostridium acetobutylicum, have required pretreatment to eliminate tannins inhibiting the strain's amylolytic activity. This study investigates biobutanol production enhancement by immobilizing enzymes on polydopamine-functionalized polyethersulfone (PES) membranes with magnetic nanoparticles for Separated Hydrolysis and Fermentation (SHF) and Simultaneous Saccharification and Fermentation (SSF) processes. After multi-stage hot water treatment, TG3 sorghum (from the third stage) was used, where the enzyme-immobilized PES membrane produced 4.75 g/L of ABE (3.24 g/L butanol) under SSF, 0.85 g/L under SHF, and 1.1 g/L under simple fermentation. For TG6 (from the sixth stage), 3.23, 1.29, and 1.25 g/L of ABE was produced under SSF, SHF, and simple fermentation, respectively. This enhanced performance is due to the reduced enzyme inhibition. Reusability experiments showed that the membrane retained 30 % of initial activity after three cycles. These findings suggest that enzyme-immobilized membranes can intensify ABE production and enable integrated cell recovery. © 2025 Elsevier Ltd
