一株黑曲霉产纤维素酶的性质研究

目的]为黑曲霉的实际应用提供依据。方法]摇瓶培养黑曲霉得到纤维素酶粗酶液,测定C1酶、Cx酶、BG酶的活力,研究温度、pH值、底物浓度、金属离子对不同酶组分活力的影响。结果]黑曲霉分泌的纤维素酶较全,但不同酶组分的分泌高峰并不一致。C1酶、BG酶的最适温度为60℃,Cx酶的最适温度为70℃。Cx酶、BG酶最适pH值4～5,C1酶最适pH值在4左右。C1酶、BG酶随底物浓度升高,活力升高,底物浓度为1.000%时活力最高。Cx酶在底物浓度为0.500%～0.625%时活力最高。Ca2+、Fe2+对酶有强烈的抑制作用,Ba2+、Mn2+对酶有一定的激活作用,Zn2+、Cu2+对Cx酶、C1酶活力有抑制作用,对BG酶有激活作用。结论]不同反应条件对不同酶组分的活力影响各异。黑曲霉纤维素酶系在60～70℃、pH值4～5时最稳定。

Study on the Property of Producing Cellulase by a Strain of Aspergillus niger

Objective] The aim of the study was to provide foundation for the practical application of Aspergillus niger.Method] The crude enzyme solution of cellulase was obtained by shake-flask culture of A.niger and the activities of Cl,Cx and BG enzymes were determined to study the influences of temperature,pH value,substrate concentration and metal ions on the activities of different enzyme components.Result] The cellulase excreted by A.niger was more complete,but the exudation peaks of different enzyme components were disaccording.The optimum temperature of Cl and BG enzymes was 60 ℃,and that of Cx enzyme was 70 ℃.The optimum pH value of Cx and BG enzymes was 4～5,that of Cl enzyme was about 4.The activities of Cl and BG enzymes increased along with the increment of substrate concentration,and was highest when the substrate concentration was 1.000%.The activity of Cx enzyme was highest when the substrate concentration was 0.500%～0.625%.Ca2+ and Fe2+ had strong restraining effect on the enzymes,Ba2+ and Mn2+ had some activation effect on the enzymes,and Zn2+ and Cu2+ had restraining effect on the activity of Cx and Cl enzymes and activation effect on BG enzyme.Conclusion] The influences of different reaction conditions on the activities of different enzyme components were different.The cellulase system of A.niger was most stable when the temperature was 60～70 ℃ and pH values were 4～5.