3 years ago

β-galactosidase covalent immobilization over large-pore mesoporous silica supports for the production of high galacto-oligosaccharides (GOS)

β-galactosidase covalent immobilization over large-pore mesoporous silica supports for the production of high galacto-oligosaccharides (GOS)
Large-pore mesoporous silica supports with different structure and pore sizes distribution have been tested for glyoxyl multipoint covalent immobilization of Pectinex Ultra SP-L, a commercial preparation including the enzyme β-galactosidase from Aspergillus aculeatus. The prepared biocatalysts have been assayed in the production of galacto-oligosaccharides (GOS) from lactose as prebiotic functional food, aiming to optimize the yield to the GOS having the highest presumed prebiotic effect, tri- and tetra- GOS (high-GOS). Immobilization of β-galactosidase over glyoxyl-modified silica supports, with pores, large enough to accommodate the enzyme within their structure, led to an enhancement of the enzyme activity in terms of high-GOS production relative to the free enzyme under the same reaction conditions. Remarkably, such an improvement was achieved without previous purification of β-galactosidase from the commercial source. An enhancement of the transgalactosylation activity over the hydrolytic activity, due to the relatively hydrophobic nature of organically modified silica surface of the supports, led to an increase in the selectivity to high-GOS. The best biocatalyst in the series was that based in hexagonal ultra-large-pore SBA-15 (ULP-SBA-15), which presents the most adequate balance between confinement effect within its pore framework and transgalactosylation activity leading to a remarkable yield to high-GOS of 20.2% vs. 11.2% for the enzyme in free conditions. Furthermore, reusability of these silica-based biocatalysts in three consecutive 24 h reaction-cycles has been successfully performed at 50 °C, temperature that minimizes the thermal deactivation of the enzyme.

Publisher URL: www.sciencedirect.com/science

DOI: S1387181117305565

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.