针对脂环酸芽孢杆菌对果汁工业的巨大威胁，该研究制备了一种抗菌材料，即溶菌酶接枝的带有聚多巴胺涂层的纤维素磁球，对该磁球进行了结构表征和抗菌试验。结果表明：FT-IR、XPS和EDS谱图结果证实了聚多巴胺和溶菌酶成功修饰在磁球表面；XRD结果显示纤维素的晶形结构由纤维素I转化为纤维素II，γ-Fe2O3使溶菌酶接枝的纤维素磁球LCs的II型晶体特征峰强度较纯纤维素球CB明显降低；热重分析结果表明再生纤维素磁球RC与LC-2、LC-3的最大降解速率温度依次为346、349和343 ℃，对应的最大降解速率绝对值依次为1.84、1.44和1.16，表明聚多巴胺涂层提升了纤维素磁球的热稳定性；VSM结果显示RC、LC-1和LC-3的饱和磁化强度分别为5.68、5.54和5.38 emu/g，磁球具备超顺磁特性；抗菌试验表明磁球能够抑制脂环酸芽孢杆菌的生长，LC-3的抑制效果最好。综上所述，该磁球具有抗菌性能优良，热稳定性高且磁响应性灵敏、便于回收等特点，该研究结果为纤维素磁球在果汁领域的实际应用提供理论依据。

Aiming at the great threat of Alicyclobacillus acidoterrestris to the juice industry, a kind of antibacterial material, i. e. polydopamine-coated cellulose magnetic beads with grafted lysozyme, was prepared in this study. The structure of the magnetic beads was characterized and the antibacterial test was carried out. The results of FT-IR, XPS and EDS showed that polydopamine and lysozyme were successfully modified on the surface of magnetic beads. XRD results showed that the crystalline structure of cellulose was transformed from cellulose I to cellulose II, and γ-Fe2O3 significantly reduced the intensity of type II crystal characteristic peaks of lysozyme-grafted cellulose magnetic beads LCs compared with the pure cellulose beads CB. The results of thermogravimetric analysis showed that the temperatures corresponding to the maximum degradation rates of regenerated cellulose magnetic beads RC, LC-2 and LC-3 were 346, 349 and 343 ℃, respectively, and the absolute values of the corresponding maximum degradation rates were 1.84, 1.44 and 1.16, respectively, indicating that the polydopamine coating improved the thermal stability of cellulose magnetic beads. VSM results showed that the saturation magnetization of RC, LC-1 and LC-3 were 5.68, 5.54 and 5.38 emu/g, respectively, and the beads had superparamagnetic properties. The antibacterial tests revealed that magnetic beads could inhibit the growth of A. acidoterrestris, with LC-3 being the most effective. In summary, the magnetic beads have characteristics such as excellent antibacterial properties, high thermal stability, sensitive magnetic response and easy recovery. The results of this study provide a theoretical basis for the practical application of cellulose magnetic beads in the field of fruit juice.

国家自然科学基金面上项目（32172166）；农业农村部富硒产品开发与质量控制重点实验室/富硒食品开发国家地方联合工程实验室开放课题资助项目(SE-2021B06)