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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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Magnetization curves and coercivity measurements at 300 K of Fe3O4 nanoparticles at different stages of synthesis and modification up to the immobilization of cellulase: curve (a) represents β-CD-modified Fe3O4; curve (b) represents APTES-modified particles; curve (c) represents glutaraldehyde-conjugated particles; curve (d) represents cellulase-bound particles.
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fig5: Magnetization curves and coercivity measurements at 300 K of Fe3O4 nanoparticles at different stages of synthesis and modification up to the immobilization of cellulase: curve (a) represents β-CD-modified Fe3O4; curve (b) represents APTES-modified particles; curve (c) represents glutaraldehyde-conjugated particles; curve (d) represents cellulase-bound particles.

Mentions: The magnetic properties of the magnetite nanoparticles were measured by the Quantum Design MPMS-XL7 magnetometer with the application of field dependence of magnetization. The values of saturation magnetization and coercivity are shown in Figure 5 and tabulated in Table 1. The nanoparticles at each step were superparamagnetic in nature. However, the saturation magnetization value was gradually reduced from 64.7 to 50.7 emg g−1 and the coercivity value was gradually increased from 0.288 to 3.82 Oe when the nanomagnetite was modified stepwise from Fe3O4-(β-CDs) to Fe3O4-(β-CDs)-AP-GE, respectively. In other words, when cellulase was immobilized onto Fe3O4-(β-CDs), the barrier of magnetite was produced by each following modification. Morphological analysis of immobilized cellulase by TEM (Figure 6) and SEM (Figure 7) showed that the average particle size was approximately 30 nm.


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)

Magnetization curves and coercivity measurements at 300 K of Fe3O4 nanoparticles at different stages of synthesis and modification up to the immobilization of cellulase: curve (a) represents β-CD-modified Fe3O4; curve (b) represents APTES-modified particles; curve (c) represents glutaraldehyde-conjugated particles; curve (d) represents cellulase-bound particles.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig5: Magnetization curves and coercivity measurements at 300 K of Fe3O4 nanoparticles at different stages of synthesis and modification up to the immobilization of cellulase: curve (a) represents β-CD-modified Fe3O4; curve (b) represents APTES-modified particles; curve (c) represents glutaraldehyde-conjugated particles; curve (d) represents cellulase-bound particles.
Mentions: The magnetic properties of the magnetite nanoparticles were measured by the Quantum Design MPMS-XL7 magnetometer with the application of field dependence of magnetization. The values of saturation magnetization and coercivity are shown in Figure 5 and tabulated in Table 1. The nanoparticles at each step were superparamagnetic in nature. However, the saturation magnetization value was gradually reduced from 64.7 to 50.7 emg g−1 and the coercivity value was gradually increased from 0.288 to 3.82 Oe when the nanomagnetite was modified stepwise from Fe3O4-(β-CDs) to Fe3O4-(β-CDs)-AP-GE, respectively. In other words, when cellulase was immobilized onto Fe3O4-(β-CDs), the barrier of magnetite was produced by each following modification. Morphological analysis of immobilized cellulase by TEM (Figure 6) and SEM (Figure 7) showed that the average particle size was approximately 30 nm.

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