The Increase of thermal stability of a-amylase from locale bacteria Isolate Sac/7/t/s subtilis ITBCCB148 by chemical modification with dimethyladipimidate

摘要

The attempt to increase thermal stability of alpha-amylase from local bacteria isolate Bacillus subtilis ITBCCB148 was performed by chemical modification using dimethyladipimidate (DMA). The results showed that the native and modified enzymes with DMA(0.3%; 0.5%; and 0.7%) have a similar optimum temperature of 60deg C. The thermal stability test done to the native and modified enzymes at 60deg C and 60 minutes showed that the native enzyme have a residual activity of 7.7% and t_1,2 of 15.4 min, while t_1/2 0f the modified enzymes were 23.9,43.3 and 53.3 min. with residual activity of 15.9%, 35.5%, and 42.5, respectively The chemical modification with DMA to alpha-amylase has shown to increase the thermal stability of the enzyme between 1.5 - 3.5 times compared to that of the native enzyme.