为了改善游离酶稳定性差、易失活、不易储存等缺点,将还原氧化石墨烯(RGO)作为载体进行溶菌酶固定化研究。考察了溶菌酶浓度、缓冲液pH和固定化时间对固定化酶活力的影响,通过正交实验得出最佳固定化条件,溶菌酶质量浓度为0.5 mg/mL、缓冲液pH为6.0、固定化时间为2 h时,固定化酶的活力最高。固定化酶的最适温度为55℃、最适pH为6.5,热稳定性、耐酸碱性和储存稳定性都比游离酶有所提高。固定化酶的抑菌性明显优于游离酶,对金黄色葡萄球菌、大肠杆菌和白色念珠菌均具有较好的抑制效果。

In order to overcome the disadvantages of free enzyme,such as poor stability,easy inactivation and poor storage,reduced graphene oxide (RGO) is used as a carrier for lysozyme immobilization.The effects of lysozyme concentration,buffer pH and immobilization time on the activity of the immobilized enzyme are investigated,and the optimal immobilization conditions are obtained through orthogonal experiments.The highest activity of the immobilized enzyme is obtained when the mass concentration of lysozyme is 0.5 mg·mL^-1,the buffer pH is 6.0 and the immobilization time is 2 h.The optimum temperature and pH of the immobilized enzyme are 55℃ and 6.5,respectively.The thermal stability,bacteriostatic property,acid and alkaline resistances,and storage stability of the immobilized enzyme are all better than that of the free enzyme.The immobilized enzyme has better inhibition effect on Staphylococcus aureus,Escherichia coli and Candida albicans.