Effect of [H+] on the Activity of α-Amylase Isolated from Bacillus Subtilis

Abstract

Without enzyme pre-incubation at the appropriate enzyme concentration, at different pH's and at different substrate concentrations, separately for each and optimal pH values were determined after the enzyme was pre-incubated for 120 minutes with buffer at each pH. The optimal pH was found to be 7.12 in both conditions. To examine the effect of pH on enzyme stability, the enzyme was pre-incubated for 120 minutes at the previously determined optimal pH at a constant substrate concentration ([S] = 2.52 µg/µL). It was found that pH₁ = pK_a = 6.15 and pH₂ = pK_b = 8.68 and optimal pH = 7.415. K_M values for enzyme (4.898; 4.7311; 5.004; 1.4615; 0.2483; 1.6666 µg/µL) by studying Michaelis-Menten kinetics at different pH's.and Vmax values (2.023; 2.431; 2.542; 0.952; 0.117; 0.438 µmol/min.) were found.