Structure and effect on Bifidobacterium longum of exopolysaccharide produced by Weissella cibaria using cost-effective substrates

Abstract

Maize straw, an abundant agricultural residue, has potential as an eco-friendly resource. The aim of this study was to investigate the structure and effect on Bifidobacterium longum of exopolysaccharide produced by Weissella cibaria using maize straw as a carbon source. In this work, an exopolysaccharide-producing strain was isolated from vegetable juice, which was identified as W. cibaria. Our results demonstrated that exopolysaccharide produced by W. cibaria is a linear glucan containing an α-1,6 glycosidic bond with a molecular weight of 9462 Da. In addition, scanning electron microscopy of exopolysaccharide from W. cibaria revealed the flake structures. In vitro assays showed that the exopolysaccharide from W. cibaria has the ability to stimulate the proliferation of B. longum strain and its metabolism to produce acetic acid. This work provides a scientific reference for the potential application of maize straw and a new insight into an eco-friendly carbon source to produce exopolysaccharide.