LAUSR

A special levan-type exopolysaccharide (EPS) from Bacillus amyloliquefaciens JN4 with anti-adhesive activity against enterotoxigenic Escherichia coli (ETEC) was purified and identified. Chemical analysis indicated that EPS-JN4 with low molecular weight of 8 kDa is composed of fructose and glucose with a molar ratio of 46.1:1. Structural analysis clarified that EPS-JN4 contains a main chain of β-(2,6)-linked Fruf residues, and intensive branches of a single 2-linked Fruf at every six residues. Furthermore, the superior anti-adhesive activity of EPS-JN4 against ETEC showed its potential usage as an anti-adhesive agent for diarrhea prevention. EPS-JN4 is a specific type of levan family, for its small molecular size and intensive branches. The results expand the knowledge on structural types of levan and illustrate its potential as an anti-adhesive agent for diarrhea prevention, which will be conducive to elucidate the relation between structure and function.