Production of thermostable endo-1,5-α-L-arabinanase in Pichia pastoris for enzymatically releasing functional oligosaccharides from sugar beet pulp

Document Type

Article

Publication Title

Applied microbiology and biotechnology

PubMed ID

31879825

MeSH Headings (Medical Subject Headings)

Beta vulgaris (chemistry); Cell Line; Colon; Enzyme Stability; Epithelial Cells (drug effects); Glycoside Hydrolases (biosynthesis, genetics); Humans; Hydrogen-Ion Concentration; Occludin (genetics); Oligosaccharides (chemistry); Pichia (enzymology); Recombinant Proteins (biosynthesis, genetics); Temperature; Zonula Occludens-1 Protein (genetics)

Abstract

Sugar beet pulp is an agricultural processing residue that is a rich source of the cell wall polysaccharide arabinan. Functional oligosaccharides, specifically feruloylated arabino-oligosaccharides (FAOs), can be isolated from sugar beet pulp through selective action by endo-arabinanase (glycoside hydrolase family 43). This study aimed to develop yeast (Pichia pastoris) as an efficient, eukaryotic platform to produce a thermophilic endo-1,5-α-L-arabinanase (TS-ABN) for extracting FAOs from sugar beet pulp. Recombinant TS-ABN was secreted into yeast culture medium at a yield of ~ 80 mg/L, and the protein exhibited specific enzyme activity, pH and temperature optimum, and thermostability comparable to those of the native enzyme. Treatment of sugar beet pulp with Pichia-secreted TS-ABN released FAOs recovered by hydrophobic chromatography at 1.52% (w/w). The isolated FAOs averaged seven arabinose residues per ferulic acid, and treatment of T84 human colon epithelial cells significantly increased expression of two key tight junction-related proteins-zonula occludens-1 and occludin-in a dose-dependent manner. This research establishes a biochemical platform for utilizing sugar beet pulp to produce value-added bioproducts with potential nutraceutical applications.

First Page

1595

Last Page

1607

DOI

10.1007/s00253-019-10238-x

Publication Date

2-1-2020

E-ISSN

1432-0614

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