Continuous degradation of maltose: Improvement in stability and catalytic properties of maltase (α-glucosidase) through immobilization using agar-agar gel as a support

Maltose degrading enzyme was immobilized within agar-agar support via entrapment method due to its industrial utilization. The maximum immobilization efficiency (82.77 %) was achieved using 4.0 % agar-agar keeping the diameter of bead up to 3.0 mm. The matrix entrapment showed maximum catalytic activity at pH 7.0 and temperature 65 C. Substrate saturation kinetics showed that the Km of immobilized enzyme increased from 1.717 to 2.117 mM ml-1 where as Vmax decreased from 8,411 to 7,450 U ml-1 min-1 as compared to free enzyme. The immobilization significantly increased the stability of maltase against various temperatures and immobilized maltase retain 100 % of its original activity after 2 h at 50 C, whereas the free maltase only showed 60 % residual activity under same condition. The reusability of entrapped maltase showed activity up to 12 cycles and retained 50 % of activity even after 5th cycle. Storage stability of agar entrapped maltase retain 73 % of its initial activity even after 2 months when stored at 30 C while free enzyme showed only 37 % activity at same storage conditions.