Co‐immobilization of multiple enzymes on ferromagnetic nanoparticles for the depolymerization of xyloglucan

• Published in: Biofuels, bioproducts and biorefining Vol. 16; no. 6; pp. 1682 - 1695
• Main Authors: Soares, Jessica M., Carneiro, Lara A. B. C., Barreto, Matheus Q., Ward, Richard J.
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.11.2022; Wiley Subscription Services, Inc
• Subjects: Catalytic activity; Cell walls; Chitosan; Depolymerization; E coli; endo‐xyloglucanase; Enzymes; EXG1 protein; Ferromagnetism; Galactose; Glucosidase; Immobilization; immobilized enzyme; Immobilized enzymes; Iron oxides; Mass spectrometry; Mass spectroscopy; Nanoparticles; Polysaccharides; Recombinants; Saccharification; Seeds; Xyloglucan; Xyloglucanase; Xylosidase; α‐xylosidase; β‐galactosidase; β‐glucosidase
• ISSN: 1932-104X; 1932-1031
• DOI: 10.1002/bbb.2407

Xyloglucan (XG) is an abundant polysaccharide in plant cell walls and some seeds and requires at least four different enzymes for complete depolymerization. Recombinant xyloglucanase from Aspergillus niveus (XegA), α‐xylosidase from Escherichia coli (YicI), β‐galactosidase from Hypocrea jecorina (Bga1) and β‐glucosidase from H. jecorina (Bgl1) were covalently immobilized individually and in combination on chitosan‐coated ferromagnetic iron oxide nanoparticles functionalized with glutaraldehyde. All immobilized enzymes presented reduced specific catalytic activity, where immobilized YicI, XegA, Bga1 and Bgl1 retained 14.9, 76.9, 29.5 and 6.6% activity as compared with the free enzymes, respectively. Immobilized and free enzymes presented similar optimum catalytic pH and optimum catalytic temperatures differed by ±10°C between the free and immobilized enzymes. Bga1 and Bgl1 presented decreased maximum catalytic temperatures (Topt), while YicI presented an increased Topt. The Topt of XegA remained unaltered. Mass spectrometry confirmed that nanoparticles carrying all four co‐immobilized enzymes degraded XG to glucose, galactose and xylose, and higher proportions of co‐immobilized Bgl1 and XegA resulted in higher XG saccharification. Although levels of Bgl1 activity were limiting, five re‐use cycles of the co‐immobilized enzymes were demonstrated, providing proof‐of‐principle for the use of a four‐component multienzyme nanoparticle in the breakdown of a complex polysaccharide. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd.