金属离子和乙二胺四乙酸对漆酶活化竹材产生活性氧类自由基的影响

Effects of Metal Ions and EDTA on ROS Free Radical Produced from Laccase-treated Bamboo Powder

为了使漆酶能更有效地应用于制造无胶竹材人造板,添加不同金属离子盐和乙二胺四乙酸(ED-TA),通过电子自旋共振(ESR)波谱测定在漆酶处理竹材的过程中产生的自由基,研究不同的添加剂对漆酶活化竹材产生活性氧类(ROS)自由基的影响。结果表明:Cu2+对漆酶活化竹材的自由基反应有明显激活作用;Fe3+、Fe2+对漆酶活化竹材的自由基反应有一定激活作用;K+、Mg2+对漆酶活化竹材的自由基反应有一定抑制作用;EDTA对漆酶活性有明显的抑制作用。

Five metal ions （Cu^2＋, K^＋ , Fe^2＋ , Mg^2＋, Fe^3＋） and EDTA were added to the lacease-bamboo treatment system. Reactive oxygen species （ROS） was detected in lacease-catalyzed oxidation of bamboo powder by electron spin resonance （ESR） spectra. The effects of five metal ions and EDTA on ROS relative strengths were investigated so as to choose proper activator to improve the relative intensity of free radical intermediates and thus to enhance the adhesion between bamboo particles when particleboard was made. Result shows that Cu^2＋ significantly activates the free radical reaction, and Fe^3 ＋ Fe^2 ＋ have a slight activation effect on the ROS relative strength in the suspension liquid. There is a marked inhibition of the ROS relative intensity when EDTA is used, and K^＋, Mg^2＋ slightly inhibit the free radical reaction.