Abstract
Amylases are enzymes that are known to hydrolyze starch. High efficiency of amylolytic enzymes allows them to compete in the industry with the technology of chemical hydrolysis of starch. A Bacillus licheniformis strain with high amylolytic activity was isolated from soil and designated as T5. The gene encoding α-amylase from B. licheniformis T5 was successfully expressed in both Escherichia coli (rAmyT5-E) and Pichia pastoris (as rAmyT5-P). According to the study, the recombinant α-amylases rAmyT5-E and rAmyT5-P exhibited the highest activity at pH 6.0 and temperatures of 70 and 80 °C, respectively. Over 80% of the rAmyT5-E enzyme activity was preserved following incubation within the pH range of 5-9; the same was true for rAmyT5-P after incubation at pH 6-9. N-glycosylation reduced the thermal and pH stability of the enzyme. The specific activity and catalytic efficiency of the recombinant AmyT5 α-amylase were also diminished by N-glycosylation.