地衣芽孢杆菌RT7PE1产可消化生淀粉碱性α-淀粉酶的固态发酵及其特性

Tabassum Romana, Khaliq Shazia, Rajoka Muhammad Ibrahim, Agblevor Foster

National Institute for Biotechnology and Genetic Engineering (NIBGE), P.O. Box 577, Faisalabad, Pakistan.

Department of Bioinformatics, G C University, Faisalabad, Pakistan.

Biotechnol Res Int. 2014;2014:495384. doi: 10.1155/2014/495384. Epub 2014 Jan 21.

The thermodynamic and kinetic properties of solids state raw starch digesting alpha amylase from newly isolated Bacillus licheniformis RT7PE1 strain were studied. The kinetic values Q p , Y p/s , Y p/X , and q p were proved to be best with 15% wheat bran. The molecular weight of purified enzyme was 112 kDa. The apparent K m and V max values for starch were 3.4 mg mL(-1) and 19.5 IU mg(-1) protein, respectively. The optimum temperature and pH for α -amylase were 55°C, 9.8. The half-life of enzyme at 95°C was 17h. The activation and denaturation activation energies were 45.2 and 41.2 kJ mol(-1), respectively. Both enthalpies (ΔH (∗)) and entropies of activation (ΔS (∗)) for denaturation of α -amylase were lower than those reported for other thermostable α -amylases.

对新分离的地衣芽孢杆菌RT7PE1菌株固态生淀粉消化性α-淀粉酶的热力学和动力学性质进行了研究。结果表明，在添加15%麦麸的情况下，动力学参数Q p、Y p/s、Y p/X和q p表现最佳。纯化酶的分子量为112 kDa。淀粉的表观K m和V max值分别为3.4 mg mL(-1)和19.5 IU mg(-1)蛋白质。α-淀粉酶的最适温度和pH分别为55°C和9.8。该酶在95°C下的半衰期为17小时。活化能和变性活化能分别为45.2和41.2 kJ mol(-1)。α-淀粉酶变性的焓变(ΔH (∗))和活化熵变(ΔS (∗))均低于其他耐热α-淀粉酶的报道值。