Yagar Hulya, Ertan Figen, Balkan Bilal
Faculty of Science and Art, Department of Chemistry, Trakya University, Edirne, Turkey.
Prep Biochem Biotechnol. 2008;38(1):13-23. doi: 10.1080/10826060701774304.
Some properties of immobilized alpha-amylase by Aspergillus sclerotiorum within calcium alginate gel beads were investigated and compared with soluble enzyme. Optimum pH and temperature were found to be 5.0 and 40 degrees C, respectively, for both soluble and immobilized enzymes. The immobilized enzyme had a better Km value, but kcat/Km values were the same for both enzymes. Entrapment within calcium alginate gel beads improved, remarkably, the thermal and storage stability of alpha-amylase. The half life values of immobilized enzyme and soluble enzyme at 60 degrees C were 164.2, and 26.2 min, respectively. The midpoint of thermal inactivation (Tm) shifted from 56 degrees C (for soluble enzyme) to 65.4 degrees C for immobilized enzyme. The percentages of soluble starch hydrolysis for soluble and immobilized alpha-amylase were determined to be 97.5 and 92.2% for 60 min, respectively.
研究了由核盘菌固定在海藻酸钙凝胶珠中的α-淀粉酶的一些性质，并与可溶性酶进行了比较。发现可溶性酶和固定化酶的最佳pH值和温度分别为5.0和40℃。固定化酶具有更好的Km值，但两种酶的kcat/Km值相同。包埋在海藻酸钙凝胶珠中显著提高了α-淀粉酶的热稳定性和储存稳定性。固定化酶和可溶性酶在60℃时的半衰期值分别为164.2分钟和26.2分钟。热失活中点（Tm）从56℃（可溶性酶）变为固定化酶的65.4℃。可溶性和固定化α-淀粉酶在60分钟内对可溶性淀粉的水解率分别测定为97.5%和92.2%。
