Separation and characterization of an α-glucosidase and maltase from Bacillus amyloliquefaciens

Publisher Website
Google Scholar
Abstract
A novel α-glucosidase and a maltase were isolated from Bacillus amyloliquefaciens. The formation of both enzymes was induced by trehalose, sucrose, or lactose in the growth medium. Trehalose is by far the most efficient inducer of both systems. The α-glucosidase and maltase were separated and purified by ion-exchange chromatography on DEAE Bio-Gel A. Purified α-glucosidase hydrolysed p-nitrophenyl-α-D-glucoside, isomaltose, and isomaltotriose but sucrose, maltose, or related saccharides were not attacked. β-Glucosides and polymeric glucosides were not degraded. The optimum temperature for α-glucosidase activity was 40 °C and its pH optimum was 5.3. The molecular weight and isoelectric point (pI) of the enzyme were 27 000 and 4.6, respectively. Purified maltase attacked maltose and sucrose, while maltotriose and melezitose were hydrolysed at slower rates and p-nitrophenyl-α-D-glucoside was not degraded. Other properties of the maltase were as follows: optimum temperature for activity, 30 °C; pH optimum, 6.5; molecular weight, 64 000; and pI, 4.7.