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Catalysis of rice straw hydrolysis by the combination of immobilized cellulase from Aspergillus niger on β-cyclodextrin-Fe3O4 nanoparticles and ionic liquid.

Huang PJ, Chang KL, Hsieh JF, Chen ST - Biomed Res Int (2015)

Bottom Line: Cellulase from Aspergillus niger was immobilized onto β-cyclodextrin-conjugated magnetic particles by silanization and reductive amidation.Ninety percent of cellulase was immobilized, but the activity of immobilized cellulase decreased by 10%.Therefore, immobilized cellulase can hydrolyze rice straw continuously compared with free cellulase.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biological Chemistry, Academia Sinica, 128 Section 2, Academia Road, Nankang, Taipei 115, Taiwan.

ABSTRACT
Cellulase from Aspergillus niger was immobilized onto β-cyclodextrin-conjugated magnetic particles by silanization and reductive amidation. The immobilized cellulase gained supermagnetism due to the magnetic nanoparticles. Ninety percent of cellulase was immobilized, but the activity of immobilized cellulase decreased by 10%. In this study, ionic liquid (1-butyl-3-methylimidazolium chloride) was introduced into the hydrolytic process because the original reaction was a solid-solid reaction. The activity of immobilized cellulase was improved from 54.87 to 59.11 U g immobilized cellulase(-1) at an ionic liquid concentration of 200 mM. Using immobilized cellulase and ionic liquid in the hydrolysis of rice straw, the initial reaction rate was increased from 1.629 to 2.739 g h(-1) L(-1). One of the advantages of immobilized cellulase is high reusability--it was usable for a total of 16 times in this study. Compared with free cellulase, magnetized cellulase can be recycled by magnetic field and the activity of immobilized cellulase was shown to remain at 85% of free cellulase without denaturation under a high concentration of glucose (15 g L(-1)). Therefore, immobilized cellulase can hydrolyze rice straw continuously compared with free cellulase. The amount of harvested glucose can be up to twentyfold higher than that from the hydrolysis by free cellulase.

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The particle size distributions of Fe3O4 that were synthesized under different conditions: (a) Fe3O4; (b) Fe3O4-oleic acid; (c) Fe3O4-oleic acid-(β-CDs): Fe2+/Fe3+/β-CDs = 0.33/1/1.
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fig2: The particle size distributions of Fe3O4 that were synthesized under different conditions: (a) Fe3O4; (b) Fe3O4-oleic acid; (c) Fe3O4-oleic acid-(β-CDs): Fe2+/Fe3+/β-CDs = 0.33/1/1.

Mentions: XRD was conducted to identify the MNPs that were prepared with ferrous and ferric salts in varying concentrations of β-cyclodextrin. Five samples were produced with the following compositions: Fe2+/Fe3+/CDs = 0.33/1/0, Fe2+/Fe3+/CDs = 0.33/1/0.02, Fe2+/Fe3+/CDs = 0.33/1/0.1, Fe2+/Fe3+/CDs = 0.33/1/0.5, and Fe2+/Fe3+/CDs = 0.33/1/1 (Figure 1). Other common coprecipitates, such as Fe(OH)3 or Fe2O3, were not observed because the positions of the main peaks only matched well with those from the JCPDS card (19-0629) for Fe3O4. Our method of MNP preparation yielded highly pure Fe3O4 particles (Figure 2). Size measurement by the Zeta-sizer revealed that the average size of the Fe3O4 particles was 28.05 nm. The addition of oleic acid as a surfactant led to a decrease in particle size down to 10.1 nm. The subsequent addition of β-cyclodextrin to the samples with Fe2+/Fe3+/CDs ratios of 0.33/1/0.1 and 0.33/1/1 further reduced the average particle size down to 6.2 and 4.5 nm, respectively. Notably, as the β-cyclodextrin concentration increased, the size of the obtained Fe3O4 crystallite decreased. These results showed that β-cyclodextrin can be used to effectively limit the particle size of magnetite.


Catalysis of rice straw hydrolysis by the combination of immobilized cellulase from Aspergillus niger on β-cyclodextrin-Fe3O4 nanoparticles and ionic liquid.

Huang PJ, Chang KL, Hsieh JF, Chen ST - Biomed Res Int (2015)

The particle size distributions of Fe3O4 that were synthesized under different conditions: (a) Fe3O4; (b) Fe3O4-oleic acid; (c) Fe3O4-oleic acid-(β-CDs): Fe2+/Fe3+/β-CDs = 0.33/1/1.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385602&req=5

fig2: The particle size distributions of Fe3O4 that were synthesized under different conditions: (a) Fe3O4; (b) Fe3O4-oleic acid; (c) Fe3O4-oleic acid-(β-CDs): Fe2+/Fe3+/β-CDs = 0.33/1/1.
Mentions: XRD was conducted to identify the MNPs that were prepared with ferrous and ferric salts in varying concentrations of β-cyclodextrin. Five samples were produced with the following compositions: Fe2+/Fe3+/CDs = 0.33/1/0, Fe2+/Fe3+/CDs = 0.33/1/0.02, Fe2+/Fe3+/CDs = 0.33/1/0.1, Fe2+/Fe3+/CDs = 0.33/1/0.5, and Fe2+/Fe3+/CDs = 0.33/1/1 (Figure 1). Other common coprecipitates, such as Fe(OH)3 or Fe2O3, were not observed because the positions of the main peaks only matched well with those from the JCPDS card (19-0629) for Fe3O4. Our method of MNP preparation yielded highly pure Fe3O4 particles (Figure 2). Size measurement by the Zeta-sizer revealed that the average size of the Fe3O4 particles was 28.05 nm. The addition of oleic acid as a surfactant led to a decrease in particle size down to 10.1 nm. The subsequent addition of β-cyclodextrin to the samples with Fe2+/Fe3+/CDs ratios of 0.33/1/0.1 and 0.33/1/1 further reduced the average particle size down to 6.2 and 4.5 nm, respectively. Notably, as the β-cyclodextrin concentration increased, the size of the obtained Fe3O4 crystallite decreased. These results showed that β-cyclodextrin can be used to effectively limit the particle size of magnetite.

Bottom Line: Cellulase from Aspergillus niger was immobilized onto β-cyclodextrin-conjugated magnetic particles by silanization and reductive amidation.Ninety percent of cellulase was immobilized, but the activity of immobilized cellulase decreased by 10%.Therefore, immobilized cellulase can hydrolyze rice straw continuously compared with free cellulase.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biological Chemistry, Academia Sinica, 128 Section 2, Academia Road, Nankang, Taipei 115, Taiwan.

ABSTRACT
Cellulase from Aspergillus niger was immobilized onto β-cyclodextrin-conjugated magnetic particles by silanization and reductive amidation. The immobilized cellulase gained supermagnetism due to the magnetic nanoparticles. Ninety percent of cellulase was immobilized, but the activity of immobilized cellulase decreased by 10%. In this study, ionic liquid (1-butyl-3-methylimidazolium chloride) was introduced into the hydrolytic process because the original reaction was a solid-solid reaction. The activity of immobilized cellulase was improved from 54.87 to 59.11 U g immobilized cellulase(-1) at an ionic liquid concentration of 200 mM. Using immobilized cellulase and ionic liquid in the hydrolysis of rice straw, the initial reaction rate was increased from 1.629 to 2.739 g h(-1) L(-1). One of the advantages of immobilized cellulase is high reusability--it was usable for a total of 16 times in this study. Compared with free cellulase, magnetized cellulase can be recycled by magnetic field and the activity of immobilized cellulase was shown to remain at 85% of free cellulase without denaturation under a high concentration of glucose (15 g L(-1)). Therefore, immobilized cellulase can hydrolyze rice straw continuously compared with free cellulase. The amount of harvested glucose can be up to twentyfold higher than that from the hydrolysis by free cellulase.

Show MeSH
Related in: MedlinePlus