Trehalose synthase converts maltose into trehalose in a single conversion step via intramolecular transformation and is thus useful for industrial production. In this study, we synthesized a thermophilic trehalose synthase from Thermus antranikianii (TaTS), which was recombinantly expressed in Escherichia coli BL21(DE3). The recombinant TaTS showed the highest activity at pH 7.0 and 60°C, with the maximum trehalose yield (76.8%) obtained at pH 7.0 and 30°C. TaTS activity was stable over a wide pH and temperature range of 6-10 and 4-70°C, respectively, over 6?h of incubation. The enzyme activity was strongly inhibited by Co2+, Cu2+, Zn2+, sodium dodecyl sulfate, and Tris. TaTS showed a 1.48-fold higher catalytic efficiency (kcat/Km) for maltose than for trehalose. Overall, these results demonstrate the good application potential of the recombinant enzyme TaTS in the efficient conversion of trehalose from maltose, with superior environmental tolerance to other trehalose synthases reported.,Copyright ? 2019 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.