A novel amylosucrase was found to synthesize trehalulose as a main product.

The enzyme from Deinococcus sp. was expressed in E. coli.

Yield ratio of trehalulose to turanose was 2:1 with 2 M sucrose at 35 °C and pH7.5.

Maximum trehalulose yield reached 36% with 2 M sucrose + 0.75 M fructose.

Industrial application of this enzyme may lead to development of a valuable sweetener.

The aim of this study was to establish an efficient bioprocess for the synthesis of trehalulose as a novel sweetener. This disaccharide has 70% of the sweetness of sucrose and bioactive properties such as anti-cariogenicity and anti-oxidizing activity. In this study, amylosucrase from the Deinococcus deserti (DdAS) gene was expressed and purified. When DdAS was reacted with 2 M sucrose at 35 °C for 120 h, the yield ratio of trehalulose to turanose was approximately 2:1. The trehalulose yield increased when extrinsic fructose was added. Under optimum conditions for trehalulose synthesis, the yield reached 36% (246 g/L, sucrose basis) starting with 2 M sucrose + 0.75 M fructose and showed the highest trehalulose productivity (1.94 g/L/h). As a result, a novel amylosucrase that synthesized trehalulose as the major product was developed, in contrast to other studied amylosucrase-type enzymes. DdAS could be utilized industrially in a bioprocess for producing trehalulose as a functional sucrose alternative.

Trehalose synthase from Thermus aquaticus ATCC 33923

Amylosucrase from Deinococcus deserti

High-performance anion-exchange chromatography/pulsed amperometric detection

Trehalulose

Amylosucrase

Deinococcus deserti

Enzymatic process

Alternative sweetener

© 2022 The Authors. Published by Elsevier B.V.