The name of this type of amylase is based on the characterization of an glucoamylase family enzyme from Thermoactinomyces vulgaris. The T. vulgaris enzyme was expressed in E. coli and, like other glucoamylases, it releases beta-D-glucose from starch. However, unlike previously characterized glucoamylases, this T. vulgaris amylase hydrolyzes maltooligosaccharides (maltotetraose, maltose) more efficiently than starch (1), indicating this enzyme belongs to a class of glucoamylase-type enzymes with oligosaccharide-metabolizing activity.