Cloning and expression of a trehalose synthase from Pseudomonas putida KT2440 for the scale-up production of trehalose from maltose

Trehalose synthase (TreS) is considered to be a potential biocatalyst for trehalose production. We aimed to scale-up produce the TreS protein in Escherichia coli and further investigate the bioconversion capacity of TreS. The treS gene from Pseudomonas putida KT2440 was amplified and expressed in E. coli BL21 (DE3). The recombinant TreS showed a molecular mass of 67 kDa. Activity analysis suggested that TreS had optimal activity at a temperature of 55 degrees C, a pH of 7.4, with a substrate concentration of 30%. High-pressure liquid chromatography results indicated that this enzyme had the ability to catalyze 59% maltose into trehalose, with about 5.1% glucose as by-product. Purification analysis showed that trehalose crystals with a purity of 98% were obtained by cooling trehalose solution. The TreS from P. putida KT2440 might be a candidate for trehalose production. Further study is needed to improve the trehalose conversion rate.