Immobilized β-galactosidase BgaC from Bifidobacterium adolescentis retains stability and activity during repeated cycles of use

Abstract β-Galactosidase enzymes catalyze the hydrolysis of terminal non-reducing β-D-galactose residues in β-galactosides. These enzymes are important in producing lactose-free dairy products, reducing the lactose content of whey in dairy products, and for production of galactooligosaccharides (GOS...

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Main Authors: Daniel Mehabie Mulualem, Orla Dwan, Michelle Kilcoyne, Conor O’Byrne, Aoife Boyd
Format: Article
Language:English
Published: Springer 2025-07-01
Series:Applied Microbiology and Biotechnology
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Online Access:https://doi.org/10.1007/s00253-025-13564-5
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author Daniel Mehabie Mulualem
Orla Dwan
Michelle Kilcoyne
Conor O’Byrne
Aoife Boyd
author_facet Daniel Mehabie Mulualem
Orla Dwan
Michelle Kilcoyne
Conor O’Byrne
Aoife Boyd
author_sort Daniel Mehabie Mulualem
collection DOAJ
description Abstract β-Galactosidase enzymes catalyze the hydrolysis of terminal non-reducing β-D-galactose residues in β-galactosides. These enzymes are important in producing lactose-free dairy products, reducing the lactose content of whey in dairy products, and for production of galactooligosaccharides (GOS) as prebiotic additives to infant formula. To use β-galactosidases in industrial settings, enzyme immobilization procedures are used to enhance their activity and stability and to minimize enzyme quantities and cost. In this study, recombinant Bifidobacterium adolescentis β-galactosidase BgaC was immobilized in calcium alginate and gelatin cross-linked with glutaraldehyde. The kinetic parameters and stability properties of immobilized BgaC were characterized in comparison with free soluble enzyme. The K M for immobilized BgaC using ortho-nitrophenyl-β-galactoside (ONPG) was 810 ± 220 μM and the K M of free BgaC was 2500 ± 3 μM. The k cat and k cat/ K M of immobilized BgaC were 802 s−1 and 990 s−1 mM−1, respectively, compared to k cat and k cat/ K M values of 209 s−1 and 84 s−1 mM−1, respectively, for free BgaC. Immobilized BgaC β-galactosidase was active at all tested pH (pH 4–10), while the free enzyme had decreased activity at pH < 5.5 and > 8.0. The immobilized enzyme had optimum activity at 40 °C, while the free enzyme was most active at 37 °C. In addition, immobilization enhanced acidic pH and temperature stability compared to the free enzyme. Reutilization of the BgaC beads was assessed and the enzyme maintained 69% activity after 12 rounds of reutilization. Therefore, the enhanced performance properties of immobilized BgaC make it a promising candidate for industrial applications. Key points • Bifidobacterium adolescentis β-galactosidase BgaC was successfully immobilized • Immobilized BgaC has enhanced enzymatic activity and stability and allows recycling • Sustained activity of immobilized BgaC is advantageous for industrial applications Graphical Abstract
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spelling doaj-art-ed4aad40c18e4c00a90dafd44940fd3f2025-08-20T03:42:20ZengSpringerApplied Microbiology and Biotechnology1432-06142025-07-01109111310.1007/s00253-025-13564-5Immobilized β-galactosidase BgaC from Bifidobacterium adolescentis retains stability and activity during repeated cycles of useDaniel Mehabie Mulualem0Orla Dwan1Michelle Kilcoyne2Conor O’Byrne3Aoife Boyd4Pathogenic Mechanisms Research Group, School of Natural Sciences, University of GalwayPathogenic Mechanisms Research Group, School of Natural Sciences, University of GalwayInfectious Disease Section, School of Biological and Chemical Sciences, University of GalwayInfectious Disease Section, School of Biological and Chemical Sciences, University of GalwayPathogenic Mechanisms Research Group, School of Natural Sciences, University of GalwayAbstract β-Galactosidase enzymes catalyze the hydrolysis of terminal non-reducing β-D-galactose residues in β-galactosides. These enzymes are important in producing lactose-free dairy products, reducing the lactose content of whey in dairy products, and for production of galactooligosaccharides (GOS) as prebiotic additives to infant formula. To use β-galactosidases in industrial settings, enzyme immobilization procedures are used to enhance their activity and stability and to minimize enzyme quantities and cost. In this study, recombinant Bifidobacterium adolescentis β-galactosidase BgaC was immobilized in calcium alginate and gelatin cross-linked with glutaraldehyde. The kinetic parameters and stability properties of immobilized BgaC were characterized in comparison with free soluble enzyme. The K M for immobilized BgaC using ortho-nitrophenyl-β-galactoside (ONPG) was 810 ± 220 μM and the K M of free BgaC was 2500 ± 3 μM. The k cat and k cat/ K M of immobilized BgaC were 802 s−1 and 990 s−1 mM−1, respectively, compared to k cat and k cat/ K M values of 209 s−1 and 84 s−1 mM−1, respectively, for free BgaC. Immobilized BgaC β-galactosidase was active at all tested pH (pH 4–10), while the free enzyme had decreased activity at pH < 5.5 and > 8.0. The immobilized enzyme had optimum activity at 40 °C, while the free enzyme was most active at 37 °C. In addition, immobilization enhanced acidic pH and temperature stability compared to the free enzyme. Reutilization of the BgaC beads was assessed and the enzyme maintained 69% activity after 12 rounds of reutilization. Therefore, the enhanced performance properties of immobilized BgaC make it a promising candidate for industrial applications. Key points • Bifidobacterium adolescentis β-galactosidase BgaC was successfully immobilized • Immobilized BgaC has enhanced enzymatic activity and stability and allows recycling • Sustained activity of immobilized BgaC is advantageous for industrial applications Graphical Abstracthttps://doi.org/10.1007/s00253-025-13564-5BgaCImmobilizationEntrapmentCalcium alginateβ-GalactosidaseBifidobacterium
spellingShingle Daniel Mehabie Mulualem
Orla Dwan
Michelle Kilcoyne
Conor O’Byrne
Aoife Boyd
Immobilized β-galactosidase BgaC from Bifidobacterium adolescentis retains stability and activity during repeated cycles of use
Applied Microbiology and Biotechnology
BgaC
Immobilization
Entrapment
Calcium alginate
β-Galactosidase
Bifidobacterium
title Immobilized β-galactosidase BgaC from Bifidobacterium adolescentis retains stability and activity during repeated cycles of use
title_full Immobilized β-galactosidase BgaC from Bifidobacterium adolescentis retains stability and activity during repeated cycles of use
title_fullStr Immobilized β-galactosidase BgaC from Bifidobacterium adolescentis retains stability and activity during repeated cycles of use
title_full_unstemmed Immobilized β-galactosidase BgaC from Bifidobacterium adolescentis retains stability and activity during repeated cycles of use
title_short Immobilized β-galactosidase BgaC from Bifidobacterium adolescentis retains stability and activity during repeated cycles of use
title_sort immobilized β galactosidase bgac from bifidobacterium adolescentis retains stability and activity during repeated cycles of use
topic BgaC
Immobilization
Entrapment
Calcium alginate
β-Galactosidase
Bifidobacterium
url https://doi.org/10.1007/s00253-025-13564-5
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AT orladwan immobilizedbgalactosidasebgacfrombifidobacteriumadolescentisretainsstabilityandactivityduringrepeatedcyclesofuse
AT michellekilcoyne immobilizedbgalactosidasebgacfrombifidobacteriumadolescentisretainsstabilityandactivityduringrepeatedcyclesofuse
AT conorobyrne immobilizedbgalactosidasebgacfrombifidobacteriumadolescentisretainsstabilityandactivityduringrepeatedcyclesofuse
AT aoifeboyd immobilizedbgalactosidasebgacfrombifidobacteriumadolescentisretainsstabilityandactivityduringrepeatedcyclesofuse