Antony Navya, Balachandran S, Mohanan P V
Department of Applied Chemistry, Cochin University of Science and Technology, Kochi 22, Kerala, India.
Department of Chemistry, Mahatma Gandhi College, Thiruvananthapuram, Kerala 695 004, India.
Food Chem. 2016 Nov 15;211:624-30. doi: 10.1016/j.foodchem.2016.05.049. Epub 2016 May 14.
Diastase α-amylase extracted from malt, catalyses break down of starch into maltose. It is commonly used in food and fermentation industry. In the present study nano zinc oxide is used as support for this starch hydrolyzing enzyme. IR study revealed that the enzyme got adsorbed via electrostatic interaction with the functional groups on the support. The immobilized enzyme possessed a better heat-resistance than free enzyme. The kinetic parameters were determined using Lineweaver-Burk plot. The immobilized enzyme showed higher Km 2.08mg/ml than the free enzyme whose Km is 0.45±.05mg/ml. The Vmax of immobilized enzyme was about 2.92±.02mg/ml/min and that of free enzyme was 7.14±.02mg/ml/min, showing decrease in activity after immobilization. The immobilized enzyme showed 70% activity after 30days of storage while free enzyme lost its activity within 7days. About 80% of enzyme retained activity after 4 cycles of reuse.
从麦芽中提取的淀粉酶α-淀粉酶催化淀粉分解为麦芽糖。它常用于食品和发酵工业。在本研究中，纳米氧化锌用作这种淀粉水解酶的载体。红外研究表明，该酶通过与载体上的官能团发生静电相互作用而被吸附。固定化酶比游离酶具有更好的耐热性。使用Lineweaver-Burk图测定动力学参数。固定化酶的Km为2.08mg/ml，高于游离酶的Km（0.45±0.05mg/ml）。固定化酶的Vmax约为2.92±0.02mg/ml/min，游离酶的Vmax为7.14±0.02mg/ml/min，表明固定化后活性降低。固定化酶在储存30天后仍具有70%的活性，而游离酶在7天内失去活性。经过4次重复使用后，约80%的酶保留了活性。
