褐色高温单孢菌PE-211纤维素酶的纯化及固定化研究

Study on immobilization and purification of cellulase from Thermomonospora fusca PE-211

褐色高温单孢菌PE-211纤维素酶经硫酸铵盐析、2次SephadexG-100柱纯化,粗酶液被纯化47.5倍,比活力为54.15 IU/mg,以戊二醛为交联剂制备固定化酶.酶动力学研究表明,固定化酶的最适pH为8.5,最适温度为70℃,且固定化酶在60～80℃活力较高;该酶的耐热性很强,而固定化酶的热稳定性比原酶强;以羧甲基纤维素钠为底物,固定化酶的Km为7.19 mg/mL,Vmax为0.132 mg/(mL·min).

The cellulase from Thermomonospora fusca PE-211 is purified to get 47.5 times the purity by(NH4)2SO4 salting out and chromatographied by SephadexG-100 column gel.The specific activity of purified cellulase could be 54.15 IU/mg.Purified cellulase is immobilized on the chitosan.The study on the enzymology of cellulase shows that the optimal pH value of immobilized enzyme is 8.5,the optimal temperature of immobilized enzyme is 70℃,and at 60～80℃ the activity of immobilized enzyme was high.The thermal stability of immobilized enzyme is better than soluble enzyme at 70℃.The value of Km and Vmax of the immobilized enzyme is 7.19 mg/mL and 0.132 mg/(mL·min) with CMC-Na as the substrate.