Purification and characterization of new trehalose-producing enzymes isolated from the hyperthermophilic archae, Sulfolobus solfataricus KM1

Amylolytic activity that converts soluble starch to alpha,alpha-trehalose (trehalose), was found in the cell homogenate of the hyperthermophilic acidophilic archae, Sulfolobus solfataricus KM1. DEAE chromatography of the homogenate as well as other new reliable assay methods showed two enzymes to be essential for this activity. These enzymes, a glycosyltransferase and an amylase, were purified to homogeneity and characterized. Their molecular masses were 76 kDa and 61 kDa and activities were maximal at 70-80 degrees C and 70-85 degrees C, respectively. High thermostability was noted for each. The reaction products by the two enzymes on maltooligosaccharides were identified by H-1- and C-13-NMR spectra and HPLC analysis. The cooperative mechanism of the two enzymes was used in a new enzymatic pathway for trehalose synthesis from starch.