[Construction of a recombinant Escherichia coli for high trehalose production]

Trehalose, a compatible solute, is widely used in food, cosmetics, pharmaceutical products and organ transplantation. Nowadays, trehalose is mostly produced by enzymatic synthesis with many secondary products and lowpurity. In this study, high amount of trehalose was produced by recombinant E. ccli fermentation. First, a bifunctional trehalose gene TPSP was amplified from genome of C. hutchinscoii. Second, an expression vector pTac-HisA containing TPSP was constructed and transformed into the host E. coli. Expression of this bifunctional enzyme-TPSP converted glucose to trehalose. The result suggested that TPSP from C. hutchinsonji has been successfully expressed in E. ccoi. High amount of extracellular trehalose generated from glucose by whole-cell catalysis and After optimization, the production of trehalose in shake flasks was improved to 1.2 g/L and the relative conversion rate reached 21%. The production in bioreactor reached 13.3 g/L and the relative conversion rate reached 48.6%. It is the first time to realize the functional expression of the bifunctional enzyme-TPSP of C. hutchinsonii in E. coli and achieved the conversion form glucose to trehalose. This study laid a foundation for industrial large-scale production of trehalose.