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

ABSTRACT

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 K m 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.