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Production of Galactooligosaccharides Using β-Galactosidase Immobilized on Chitosan-Coated Magnetic Nanoparticles with Tris(hydroxymethyl)phosphine as an Optional Coupling Agent.

Chen SC, Duan KJ - Int J Mol Sci (2015)

Bottom Line: However, activity retention of batchwise reactions was similar for both immobilized systems.All the three enzyme systems produced GOS compound with similar concentration profiles, with a maximum GOS yield of 50.5% from 36% (w · v(-1)) lactose on a dry weight basis.The chitosan-coated magnetic Fe3O4 nanoparticles can be regenerated using a desorption/re-adsorption process described in this study.

View Article: PubMed Central - PubMed

Affiliation: Department of Bioengineering, Tatung University, Taipei 104, Taiwan. monica94707@yahoo.com.tw.

ABSTRACT
β-Galactosidase was immobilized on chitosan-coated magnetic Fe3O4 nanoparticles and was used to produce galactooligosaccharides (GOS) from lactose. Immobilized enzyme was prepared with or without the coupling agent, tris(hydroxymethyl)phosphine (THP). The two immobilized systems and the free enzyme achieved their maximum activity at pH 6.0 with an optimal temperature of 50 °C. The immobilized enzymes showed higher activities at a wider range of temperatures and pH. Furthermore, the immobilized enzyme coupled with THP showed higher thermal stability than that without THP. However, activity retention of batchwise reactions was similar for both immobilized systems. All the three enzyme systems produced GOS compound with similar concentration profiles, with a maximum GOS yield of 50.5% from 36% (w · v(-1)) lactose on a dry weight basis. The chitosan-coated magnetic Fe3O4 nanoparticles can be regenerated using a desorption/re-adsorption process described in this study.

No MeSH data available.


Long-term thermal stability of the enzymes at 45 °C. The data are averaged from three samples. (●) Fe3O4-CS-immobilized enzyme; (○) Fe3O4-CS-THP-immobilized enzyme; (▼) free enzyme.
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ijms-16-12499-f005: Long-term thermal stability of the enzymes at 45 °C. The data are averaged from three samples. (●) Fe3O4-CS-immobilized enzyme; (○) Fe3O4-CS-THP-immobilized enzyme; (▼) free enzyme.

Mentions: After incubation at 45 °C for 14 days, the residual activities of the Fe3O4-CS-THP- and the Fe3O4-CS-immobilized enzymes were 62% and 50%, respectively (Figure 5). The free enzyme showed a complete loss of activity after 7 days. In the Fe3O4-CS-THP immobilization system, β-galactosidase was covalently linked to the nanoparticles, while in the Fe3O4-CS system, the enzyme was immobilized to the nanoparticles by ionic force. Covalent bonding may have further restricted the flexibility of the enzyme, rendering the enzyme more resistant to unfolding or denaturation by heat. Cheng et al. reported that the same β-galactosidase immobilized on the porous chitosan beads (Chitopearl™) remained 75% residual activities after incubated at 55 °C for 14 days [5]. The results showed thermal stability of β-galactosidase immobilized on the porous chitosan beads was better than that on the nanoparticles of this investigation. Similar findings were obtained by Klein et al. where β-galactosidase (Maxilact LX 5000) was covalently bonding on the chitosan beads [28]. The macroparticles (2 mm) showed better thermal stability than that of the nanoparticles (410 nm) [28].


Production of Galactooligosaccharides Using β-Galactosidase Immobilized on Chitosan-Coated Magnetic Nanoparticles with Tris(hydroxymethyl)phosphine as an Optional Coupling Agent.

Chen SC, Duan KJ - Int J Mol Sci (2015)

Long-term thermal stability of the enzymes at 45 °C. The data are averaged from three samples. (●) Fe3O4-CS-immobilized enzyme; (○) Fe3O4-CS-THP-immobilized enzyme; (▼) free enzyme.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4490457&req=5

ijms-16-12499-f005: Long-term thermal stability of the enzymes at 45 °C. The data are averaged from three samples. (●) Fe3O4-CS-immobilized enzyme; (○) Fe3O4-CS-THP-immobilized enzyme; (▼) free enzyme.
Mentions: After incubation at 45 °C for 14 days, the residual activities of the Fe3O4-CS-THP- and the Fe3O4-CS-immobilized enzymes were 62% and 50%, respectively (Figure 5). The free enzyme showed a complete loss of activity after 7 days. In the Fe3O4-CS-THP immobilization system, β-galactosidase was covalently linked to the nanoparticles, while in the Fe3O4-CS system, the enzyme was immobilized to the nanoparticles by ionic force. Covalent bonding may have further restricted the flexibility of the enzyme, rendering the enzyme more resistant to unfolding or denaturation by heat. Cheng et al. reported that the same β-galactosidase immobilized on the porous chitosan beads (Chitopearl™) remained 75% residual activities after incubated at 55 °C for 14 days [5]. The results showed thermal stability of β-galactosidase immobilized on the porous chitosan beads was better than that on the nanoparticles of this investigation. Similar findings were obtained by Klein et al. where β-galactosidase (Maxilact LX 5000) was covalently bonding on the chitosan beads [28]. The macroparticles (2 mm) showed better thermal stability than that of the nanoparticles (410 nm) [28].

Bottom Line: However, activity retention of batchwise reactions was similar for both immobilized systems.All the three enzyme systems produced GOS compound with similar concentration profiles, with a maximum GOS yield of 50.5% from 36% (w · v(-1)) lactose on a dry weight basis.The chitosan-coated magnetic Fe3O4 nanoparticles can be regenerated using a desorption/re-adsorption process described in this study.

View Article: PubMed Central - PubMed

Affiliation: Department of Bioengineering, Tatung University, Taipei 104, Taiwan. monica94707@yahoo.com.tw.

ABSTRACT
β-Galactosidase was immobilized on chitosan-coated magnetic Fe3O4 nanoparticles and was used to produce galactooligosaccharides (GOS) from lactose. Immobilized enzyme was prepared with or without the coupling agent, tris(hydroxymethyl)phosphine (THP). The two immobilized systems and the free enzyme achieved their maximum activity at pH 6.0 with an optimal temperature of 50 °C. The immobilized enzymes showed higher activities at a wider range of temperatures and pH. Furthermore, the immobilized enzyme coupled with THP showed higher thermal stability than that without THP. However, activity retention of batchwise reactions was similar for both immobilized systems. All the three enzyme systems produced GOS compound with similar concentration profiles, with a maximum GOS yield of 50.5% from 36% (w · v(-1)) lactose on a dry weight basis. The chitosan-coated magnetic Fe3O4 nanoparticles can be regenerated using a desorption/re-adsorption process described in this study.

No MeSH data available.