Properties of the recombinant alpha-glucosidase from Sulfolobus solfataricus in relation to starch processing

An alpha -glucosidase activity (EC 3.2.1.20) isolated from Sulfolobus solfa taricus strain MT-4 was characterised and found of interest at industrial l evel in the saccharification step of hydrolysis process of starch. The gene encoding for the enzyme was expressed in Escherichia coli BL21 (DE3) with a yield of 87.5 U/g of wet biomass. The recombinant cytosolic enzyme was pu rified to homogeneity with a rapid purification procedure employing only st eps of selective and progressive thermal precipitations with a final yield of 75.4% and a purification of 14.5-fold. The properties of this thermophil ic alpha -glucosidase were compared with those of the alpha -glucosidase of a commercial preparation from Aspergillus niger used in the starch process ing. (C) 2001 Elsevier Science B.V. All rights reserved.