Department of Food Science and Technology, School of Chemistry, Universidad Autónoma de Coahuila, Saltillo, Coahuila, Mexico.
Appl Biochem Biotechnol. 2011 Nov;165(5-6):1141-51. doi: 10.1007/s12010-011-9331-y. Epub 2011 Aug 12.
Tannase is an inducible enzyme with important applications in the food and pharmaceutical industries. This enzyme was produced by the fungus Aspergillus niger GH1 under solid-state fermentation using polyurethane foam as solid support and tannic acid as sole carbon source and tannase inducer. Physicochemical properties of A. niger tannase were characterized, and the kinetic and thermodynamics parameters on methyl gallate hydrolysis were evaluated. The enzyme was stable in a pH range of 2-8 and a functional temperature range of 25-65 °C. The highest k(cat) value was 2,611.10 s(-1) at 65 °C. Tannase had more affinity for methyl gallate at 45 °C with a K(M) value of 1.82 mM and an efficiency of hydrolysis (k(cat)/K(M)) of 330.01 s(-1) mM(-1). The lowest E(a) value was found to be 21.38 kJ/mol at 4.4 mM of methyl gallate. The lowest free energy of Gibbs (ΔG) and enthalpy (ΔH) were found to be 64.86 and 18.56 kJ/mol, respectively. Entropy (ΔS) was -0.22 kJ/mol K. Results suggest that the A. niger GH1 tannase is an attractive enzyme for industrial applications due its catalytic and thermodynamical properties.
单宁酶是一种诱导酶，在食品和制药工业中有重要的应用。该酶由黑曲霉 GH1 在固态发酵下产生，以聚氨酯泡沫为固体载体，以单宁酸为唯一碳源和单宁酶诱导物。我们对黑曲霉单宁酶的理化性质进行了表征，并评估了其对甲基没食子酸水解的动力学和热力学参数。该酶在 pH 值 2-8 和功能温度范围 25-65°C 内稳定。在 65°C 时，k(cat)值最高为 2611.10 s(-1)。单宁酶在 45°C 时对甲基没食子酸具有更高的亲和力，K(M)值为 1.82 mM，水解效率(k(cat)/K(M))为 330.01 s(-1) mM(-1)。在 4.4 mM 的甲基没食子酸下，发现 E(a)值最低为 21.38 kJ/mol。最低的自由能吉布斯(ΔG)和焓(ΔH)分别为 64.86 和 18.56 kJ/mol，熵(ΔS)为-0.22 kJ/mol K。结果表明，由于其催化和热力学性质，黑曲霉 GH1 单宁酶是一种有吸引力的工业应用酶。
