Enzyme‐resistant isomalto‐oligosaccharides produced from Leuconostoc mesenteroides NRRL B‐1426 dextran hydrolysis for functional food application

Abstract

The extracellular dextransucrase from Leuconostoc mesenteroides NRRL B-1426 was produced and purified using polyethylene glycol fractionation. In our earlier study, it was reported that L. mesenteroides dextransucrase synthesizes a high-molecular mass dextran (>2 × 10(6) Da) with ∼85.5% α-(1→6) linear and ∼14.5% α-(1→3) branched linkages. Isomalto-oligosaccharides (IMOs) were synthesized through depolymerization of dextran by the action of dextranase. The degree of polymerization of IMOs was 2-10 as confirmed by mass spectrometry. The nuclear magnetic resonance spectroscopic analysis revealed the presence of α-(1→3) linkages in the synthesized IMOs. The IMOs were resistant to dextranase, α-glucosidase, and α-amylase, and therefore can have potential application as food additives in the functional foods.

Improving the thermostability of GH49 dextranase AoDex by site-directed mutagenesis

“…Dextran has broad application prospects in the food and pharmaceutical industry, and the application areas of diverse dextrans are determined by their corresponding molecular weights (Naessens et al 2005;Xue et al 2022). For example, medium molecular weight dextrans could be served as additives in the food industry, and low molecular weight dextrans could be used as plasma substitutes in the medical field (Falconer et al 2011;Kothari and Goyal 2016). However, the low or medium molecular weight dextrans are obtained by hydrolysis of dextranase, which can specifically hydrolyze α-(1 → 6) glycosidic bonds of high molecular weight dextran (Khalikova et al 2005).…”