title: Enhancing enzyme stability and metabolic functional ability of β-galactosidase through functionalized polymer nanofiber immobilization.
abstract: A functionalized polystyrene nanofiber (PSNF) immobilized β-galactosidase assembly (PSNF-Gal) was synthesized as a nanobiocatalyst aiming to enhance the biocatalyst stability and functional ability. The PSNF fabricated by electrospinning was functionalized through a chemical oxidation method for enzyme binding. The bioengineering performance of the enzyme carriers was further evaluated for bioconversion of lactose to galacto-oligosaccharides (GOS). The modified PSNF-Gal demonstrated distinguished performances to preserve the same activity as the free β-galactosidase at the optimum pH of 7.0, and to enhance the enzyme stability of PSNF-Gal in an alkaline condition up to pH 10. The PSNF assembly demonstrated improved thermal stability from 37 to 60 °C. The nanobiocatalyst was able to retain 30 % of its initial activity after ninth operation cycles comparing to four cycles with the unmodified counterpart. In contrast with free β-galactosidase, the modified PSNF-Gal enhanced the GOS yield from 14 to 28 %. These findings show the chemically modified PSNF-based nanobiocatalyst may be pertinent for various enzyme-catalysed bioprocessing applications.
authors.affiliation: School of Chemical Engineering, The University of Adelaide, Adelaide, SA, 5000, Australia.|Biotechnology Research Institute, Universiti Malaysia Sabah, Jalan UMS, 88400, Kota Kinabalu, Sabah, Malaysia.
authors.forename: Mailin
authors.initials: M
authors.lastname: Misson
authors.affiliation: School of Chemical Engineering, The University of Adelaide, Adelaide, SA, 5000, Australia.
authors.forename: Bo
authors.initials: B
authors.lastname: Jin
authors.affiliation: Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xianmen University, 361005, Xiamen, China.
authors.forename: Binghui
authors.initials: B
authors.lastname: Chen
authors.affiliation: School of Chemical Engineering, The University of Adelaide, Adelaide, SA, 5000, Australia. hu.zhang@adelaide.edu.au.
authors.forename: Hu
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000327:Adsorption; D002384:Catalysis; D004789:Enzyme Activation; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry; D007785:Lactose / Q000737:chemistry* / Q000378:metabolism; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure*; D011137:Polystyrenes / Q000737:chemistry*; D001616:beta-Galactosidase / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D004800:Enzymes, Immobilized; D011137:Polystyrenes; D001616:beta-Galactosidase; D007785:Lactose
keywords: Bioconversion; Galacto-oligosaccharides; Nanobiocatalysts; Polymer nanofibers; β-galactosidase