From fructans to difructose dianhydrides

Abstract

Fructans are the polymers of fructose molecules, normally having a sucrose unit at what would otherwise be the reducing terminus. Inulin and levan are two basic types of simple fructan, which contain β-(2, 1) and β-(2, 6) fructosyl-fructose linkage, respectively. Fructans not only can serve as soluble dietary fibers for food industry, but also may be biologically converted into high-value products, especially high-fructose syrup and fructo-oligosaccharides. In recent years, much attention has been focused on production of difructose dianhydrides (DFAs) from fructans. DFAs are cyclic disaccharides consisting of two fructose units with formation of two reciprocal glycosidic linkages. They are expected to have promising properties and beneficial effects on human health. DFAs can be produced from fructans by fructan fructotransferases. Inulin fructotransferase (IFTase) (DFA III-forming) and IFTase (DFA I-forming) catalyze the DFA III and DFA I production from inulin, respectively, and levan fructotransferase (LFTase) (DFA IV-forming) catalyzes the production of DFA IV from levan. In this article, the DFA-producing microorganisms are summarized, relevant studies on various DFAs-producing enzymes are reviewed, and especially, the comparisons of the enzymes are presented in detail.

Identification of a Recombinant Inulin Fructotransferase (Difructose Dianhydride III Forming) from Arthrobacter sp. 161MFSha2.1 with High Specific Activity and Remarkable Thermostability

“…T88-4 (644 units/mg). 16 By comparison, the IFTases from Arthrobacter strains show specific activities below 1000 units/mg, except the IFTases from Arthrobacter sp. A-6 (1,195 units/mg) 21 and the hereinreported Arthrobacter sp.…”

Levansucrases of a Pseudomonas syringae pathovar as catalysts for the synthesis of potentially prebiotic oligo- and polysaccharides

“…Literature search did not yield additional data on levansucrases from other species of Pseudomonas. Yet, there are few publications on synthesis of difructose dianhydride (DFA IV) from levan by Pca and P. fluorescens [83,86]. Most producers of this prebiotic substrate are Gram-positive bacteria such as Arthrobacter and Microbacterium [86].…”

The Hydrolysis Mechanism of Inulin and Its Hydrolysate in the Reaction Field by the Hot Compressed Water

“…Inulin is the raw material of functional oligosaccharides such as di-D-fructose dianhydrides (DFAs) that can be used as low-caloric sweeteners with low cariogenicity and prebiotic properties (Minamida et al, 2004;2005a;2005b;Mitamura and Hara, 2005;Minamida et al, 2006;Yoshimoto et al, 2013) and may also increase the absorption of essential minerals (Shigematsu et al, 2004;Hara et al, 2010;Nakamori et al, 2010), flavonoids (Matsumoto et al, 2007). The techniques for converting inulin into DFAs are almost performed with enzymatic reactions (Uchiyama et al, 1973;Haraguchi et al, 1988;Kawamura et al, 1988;Yokota et al, 1991;Cho et al, 1996;Park and Choi, 1996;Kang et al, 1998;Haraguchi et al, 2002;Zhao et al, 2011;Wang et al, 2015). The DFA producing microorganisms were summarized, 30 microbial strains have been isolated to produce DFAs via enzymatic reaction, but only four isomers have been obtained by means of this, including DFA III, DFA I, DFA IV and DFA V (Wang et al, 2015).…”

“…The techniques for converting inulin into DFAs are almost performed with enzymatic reactions (Uchiyama et al, 1973;Haraguchi et al, 1988;Kawamura et al, 1988;Yokota et al, 1991;Cho et al, 1996;Park and Choi, 1996;Kang et al, 1998;Haraguchi et al, 2002;Zhao et al, 2011;Wang et al, 2015). The DFA producing microorganisms were summarized, 30 microbial strains have been isolated to produce DFAs via enzymatic reaction, but only four isomers have been obtained by means of this, including DFA III, DFA I, DFA IV and DFA V (Wang et al, 2015). While the reactions are highly selectivity and proceed in mild temperature, culturing bacteria and purification of enzymes are the essential process and might be the bottleneck for manufacturing DFAs in enzymatic reactions.…”