Inulosucrase, an Efficient Transfructosylation Tool for the Synthesis of Microbial Inulin

Bacterial biopolymers, as renewable natural resources, have been applied widely in many fields, due to their promising properties and functions (Moradali and Rehm 2020; Rehm 2010). Therein, exopolysaccharide is one of the crucial bacterial biopolymers, which is not only widespread in plenty of microorganisms but also easy to obtain. Fructan and glucan are two types of homo-polysaccharides, consisting of fructose molecules and glucose molecules, respectively. Besides levan introduced in Chap. 9, inulin is the other significant fructan which is composed of fructosyls by β-(2,1) glycosidic bonds, and a molecule of glucose connects to the terminal of the chain.