从青霉菌m8提取出半纤维素酶,将其固定在用戊二醛交联的壳聚糖载体上.0.5 g壳聚糖与4%的戊二醛结合固定2.5 mg蛋白质,酶活回收率为45.6%. 原酶的最适pH为4.6,固定化酶为pH 3.6.原酶的最适温度为55℃,固定化酶在60~75℃都具有较高活性.固定化酶的耐热性优于原酶. 以半纤维素为底物,固定化酶的表观Km值略低于原酶,前者为5.0×10-2 g/L,后者为3.58×10-2 g/L.
The extracellular hemicellulase from Penicillium was immobilized on chitosan by glutaraldehyde.The results indicated that the immobilized-hemicellulase prepared by 0.5 g chitosan crosslinking with 4% glutaralhyde and then combining with 2.5 mg protein showed higher enzyme activity and better activity recoveries(45.6%).The optimum pH of soluble enzyme and immobilized enzyme were pH 4.6 and pH 3.6 respectively.The optimum temperature of soluble enzyme was 55℃, whereas immobilized showed high activity in 60~75℃.Thermal stability of immobilized enzyme was better than soluble enzyme at 65℃.The apparent Km′ of the immobilized enzyme was 3.58×10-2 g/L and the Km of soluble enzyme was 5.0×10-2 g/L with hemicellulose as the substrate.
朱启忠.壳聚糖固定化半纤维素酶的研究[J].生物化学与生物物理进展,2000,27(3):274-277
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