High Efficiency Expression of Trehalose Synthase in Escherichia coli and Its Use in the Production of Trehalose

摘要

Trehalose (also known as α-D-glucopyranosyl-α-D-glucopyranoside, mycose or mushroom sugar) is a kind of white, odorless powder with 45% relative sweetness of sucrose. In nature it can be found in many biological species [1] as carbon energy source [2], structural component of bacterial cell wall [3, 4], It is a non-reducing sugar formed from two glucose units joined by an α-1,1-glycosidic bond, this special bonding can prevent Maillard reaction with protein or amino [5], and then make it very stable at high temperatures or acidic conditions. Because of those special properties, trehalose have been used as osmoregulation [6], dessication protectant [7, 8], cryoprotection [9], immunogenicity [10], stabilization of drug molecules, vaccines and liposomesgainst sTreSs [11-13], preservation of mammalian cells against dessication [14] and cryoprotection of human fibroblasts and oocytes [15, 16], etc. in various industrial processes including food processing, cosmetics, pharmaceutics. In 2000, trehalose was accepted as a novel food ingredient under the generally recognized as safe (GRAS) terms in the U.S. and EU, which certainly increased the scope of trehalose application. Although trehalose is present quite widely in the nature, the commercial application of this sugar was still limited by their low yields and expensive production costs.